Moon - Blog Posts

A Tour of our Moon

Want to go to the Moon? 

Let our Lunar Reconnaissance Orbiter take you there!

Our lunar orbiter, also known as LRO, has been collecting data on lunar topography, temperature, resources, solar radiation, and geology since it launched nine years ago. Our latest collection of this data is now in 4K resolution. This updated "Tour of the Moon" takes you on a virtual tour of our nearest neighbor in space, with new science updates from the vastly expanded data trove.

Orientale Basin

First stop, Orientale Basin located on the rim of the western nearside. It's about the size of Texas and is the best-preserved impact structure on the Moon. Topography data from LRO combined with gravity measurements from our twin GRAIL spacecraft reveal the structure below the surface and help us understand the geologic consequences of large impacts.

South-Pole and Shackleton Crater

Unlike Earth, the Moon's axis is barely tilted relative to the Sun. This means that there are craters at the poles where the sunlight never reaches, called permanently shadowed regions. As a result, the Moon's South Pole has some of the coldest measured places in the solar system. How cold? -410 degrees F.

Because these craters are so cold and dark, water that happens to find its way into them never has the opportunity to evaporate. Several of the instruments on LRO have found evidence of water ice, which you can see in the highlighted spots in this visualization.

South-Pole Aitken Basin

South Pole-Aitken Basin is the Moon's largest, deepest and oldest observed impact structure. Its diameter is about 2,200 km or 1,367 miles across and takes up 1/4 of the Moon! If there was a flat, straight road and you were driving 60 mph, it would take you about 22 hours to drive across. And the basin is so deep that nearly two Mount Everests stacked on each other would fit from the bottom of the basin to the rim. South-Pole Aitken Basin is a top choice for a landing site on the far side of the Moon.

Tycho Crater

Now let's go to the near side. Tycho Crater is 100 million years young. Yes, that's young in geologic time. The central peak of the impact crater likely formed from material that rebounded back up after being compressed in the impact, almost like a spring. Check out that boulder on top. It looks small in this image, but it could fill a baseball stadium.

Aristarchus Plateau

Also prominent on the nearside is the Aristarchus Plateau. It features a crater so bright that you could see it with your naked eye from Earth! The Aristarchus Plateau is particularly interesting to our scientists because it reveals much of the Moon's volcanic history. The region is covered in rocks from volcanic eruptions and the large river-like structure is actually a channel made from a long-ago lava flow.

Apollo 17 Landing Site

As much as we study the Moon looking for sites to visit, we also look back at places we've already been. This is because the new data that LRO is gathering helps us reinterpret the geology of familiar places, giving scientists a better understanding of the sequence of events in early lunar history.

Here, we descend to the Apollo 17 landing site in the Taurus-Littrow valley, which is deeper than the Grand Canyon. The LRO camera is even able to capture a view of the bottom half of the Apollo 17 Lunar Lander, which still sits on the surface, as well as the rover vehicle. These images help preserve our accomplishment of human exploration on the Moon's surface.

North Pole

Finally, we reach the North Pole. Like the South Pole, there are areas that are in permanent shadow and others that bask in nearly perpetual light. LRO scientists have taken detailed brightness and terrain measurements of the North Pole in order to model these areas of sunlight and shadow through time.  Sunlit peaks and crater rims here may be ideal locations for generating solar power for future expeditions to the Moon.

LRO was designed as a one-year mission. Now in its ninth year, the spacecraft and the data emphasize the power of long-term data collection. Thanks to its many orbits around the Moon, we have been able to expand on lunar science from the Apollo missions while paving the way for future lunar exploration. And as the mission continues to gather data, it will provide us with many more opportunities to take a tour of our Moon. 

And HERE's the full “Tour of the Moon” video:

We hope you enjoyed the tour. If you'd like to explore the moon further, please visit moon.nasa.gov and moontrek.jpl.nasa.gov.

Make sure to follow @NASAMoon on Twitter for the latest lunar updates and photos.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Solar System: 10 Things to Know This Week

Rockets We Love-Saturn V

Fifty years ago, with President Kennedy’s Moon landing deadline looming, the powerful Saturn V had to perform. And perform it did—hurling 24 humans to the Moon.

The race to land astronauts on the Moon was getting tense 50 years ago this week. Apollo 6, the final uncrewed test flight of America’s powerful Moon rocket, launched on April 4, 1968. Several technical issues made for a less-than-perfect launch, but the test flight nonetheless convinced NASA managers that the rocket was up to the task of carrying humans. Less than two years remained to achieve President John F. Kennedy’s goal to put humans on the Moon before the decade was out, meaning the Saturn V rocket had to perform.

1—“The only chance to get to the Moon before the end of 1969.”

After the April 1968 Apollo 6 test flight (pictured above), the words of Deke Slayton (one of the original Mercury 7 astronauts) and intense competition with a rival team in the Soviet Union propelled a 12-member panel to unanimously vote for a Christmas 1968 crewed mission to orbit the Moon.

2—Four Hundred Elephants...

The Saturn V rocket stood about the height of a 36-story-tall building, and 60 feet (18 meters) taller than the Statue of Liberty. Fully fueled for liftoff, the Saturn V weighed 6.2 million pounds (2.8 million kilograms), or the weight of about 400 elephants.

3—...and Busloads of Thrust

Stand back, Ms. Frizzle. The Saturn V generated 7.6 million pounds (34.5 million newtons) of thrust at launch, creating more power than 85 Hoover Dams. It could launch about 130 tons (118,000 kilograms) into Earth orbit. That's about as much weight as 10 school buses. The Saturn V could launch about 50 tons (43,500 kilograms) to the Moon. That's about the same as four school buses.

4—Christmas at the Moon

On Christmas Eve 1968, the Saturn V delivered on engineers’ promises by hurling Frank Borman, Jim Lovell and Bill Anders into lunar orbit. The trio became the first human beings to orbit another world. The Apollo 8 crew broadcast a special holiday greeting from lunar orbit and also snapped the iconic earthrise image of our home planet rising over the lunar landscape.

5—Gumdrop and Spider

The crew of Apollo 9 proved that they could pull the lunar module out of the top of the Saturn V’s third stage and maneuver it in space (in this case high above Earth). The crew named their command module “Gumdrop.” The Lunar Module was named “Spider.”

6—The Whole Enchilada

Saturn-V AS-505 provided the ride for the second dry run to the Moon in 1969. Tom Stafford, Gene Cernan and John Young rode Command Module “Charlie Brown” to lunar orbit and then took Lunar Module “Snoopy” on a test run in lunar orbit. Apollo 10 did everything but land on the Moon, setting the stage for the main event a few months later. Young and Cernan returned to walk on the Moon aboard Apollo 16 and 17 respectively. Cernan, who died in 2017, was the last human being (so far) to set foot on the Moon.

7—The Main Event

The launch of Apollo 11—the first mission to land humans on the Moon—provided another iconic visual as Saturn-V AS-506 roared to life on Launch Pad 39A at Kennedy Space Center in Florida. Three days later, Neil Armstrong and Buzz Aldrin made the first of many bootprints in the lunar dust (supported from orbit by Michael Collins).

8—Moon Men

Saturn V rockets carried 24 humans to the Moon, and 12 of them walked on its surface between 1969 and 1972. Thirteen are still alive today. The youngest, all in their early 80s, are moonwalkers Charles Duke (Apollo 16) and Harrison Schmitt (Apollo 17) and Command Module Pilot Ken Mattingly (Apollo 16, and also one of the heroes who helped rescue Apollo 13). There is no single image of all the humans who have visited the Moon.

9—The Flexible Saturn V

The Saturn V’s swan song was to lay the groundwork for establishing a permanent human presence in space. Skylab, launched into Earth orbit in 1973, was America’s first space station, a precursor to the current International Space Station. Skylab’s ride to orbit was a Saturn IV-B 3rd stage, launched by a Saturn 1-C and SII Saturn V stages.

This was the last launch of a Saturn V, but you can still see the three remaining giant rockets at the visitor centers at Johnson Space Center in Texas and Kennedy Space Center in Florida and at the United States Space and Rocket Center in Alabama (near Marshall Space Flight Center, one of the birthplaces of the Saturn V).

10—The Next Generation

The Saturn V was retired in 1973. Work is now underway on a fleet of rockets. We are planning an uncrewed flight test of Space Launch System (SLS) rocket to travel beyond the Moon called Exploration Mission-1 (EM-1). “This is a mission that truly will do what hasn’t been done and learn what isn’t known,” said Mike Sarafin, EM-1 mission manager at NASA Headquarters in Washington.

Read the web version of this 10 Things to Know article HERE. 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Solar System: 10 Things to Know This Week

Week of March 5: Great Shots Inspiring views of our solar system and beyond

1-Mars-By-Numbers

“The first TV image of Mars, hand colored strip-by-strip, from Mariner 4 in 1965. The completed image was framed and presented to JPL director, William H. Pickering. Truly a labor of love for science!” -Kristen Erickson, NASA Science Engagement and Partnerships Director

2-Night Life

“There are so many stories to this image. It is a global image, but relates to an individual in one glance. There are stories on social, economic, population, energy, pollution, human migration, technology meets science, enable global information, etc., that we can all communicate with similar interests under one image.” -Winnie Humberson, NASA Earth Science Outreach Manager

3-Pale Blue Dot

“Whenever I see this picture, I wonder...if another species saw this blue dot what would they say and would they want to discover what goes on there...which is both good and bad. However, it would not make a difference within the eternity of space—we’re so insignificant...in essence just dust in the galactic wind—one day gone forever.”

-Dwayne Brown, NASA Senior Communications Official

4-Grand Central

“I observed the Galactic Center with several X-ray telescopes before Chandra, including the Einstein Observatory and ROSAT. But the Chandra image looks nothing like those earlier images, and it reminded me how complex the universe really is. Also I love the colors.” -Paul Hertz, Director, NASA Astrophysics Division

5-Far Side Photobomb

“This image from the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the Moon as it moved in front of the sunlit side of Earth in 2015. It shows a view of the farside of the Moon, which faces the Sun, that is never directly visible to us here on Earth. I found this perspective profoundly moving and only through our satellite views could this have been shared.” -Michael Freilich, Director NASA Earth Science Division

6-”Shocking, Exciting and Wonderful”

“Pluto was so unlike anything I could imagine based on my knowledge of the Solar System. It showed me how much about the outer solar system we didn’t know. Truly shocking, exciting and wonderful all at the same time.” -Jim Green, Director, NASA Planetary Science Division

7-Slices of the Sun

“This is an awesome image of the Sun through the Solar Dynamic Observatory’s many filters. It is one of my favorites.” - Peg Luce, Director, NASA Heliophysics Division (Acting)

8-Pluto’s Cold, Cold Heart

“This high-resolution, false color image of Pluto is my favorite. The New Horizons flyby of Pluto on July 14, 2015 capped humanity’s initial reconnaissance of every major body in the solar system. To think that all of this happened within our lifetime! It’s a reminder of how privileged we are to be alive and working at NASA during this historic era of space exploration.” - Laurie Cantillo, NASA Planetary Science Public Affairs Officer

9-Family Portrait

“The Solar System family portrait, because it is a symbol what NASA exploration is really about: Seeing our world in a new and bigger way.” - Thomas H. Zurbuchen, Associate Administrator, NASA Science Mission Directorate

10-Share Your Favorite Space Shots

Tag @NASASolarSystem on your favorite social media platform with a link to your favorite image and few words about why it makes your heart thump.

Check out the full version of this article HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.   

What’s Up - March 2018

What’s Up For March?

Several Planets and the Zodiacal Light!

This month, at sunset, catch elusive Mercury, bright Venus, the Zodiacal Light, Mars, Saturn and Jupiter between midnight and dawn!

Both Venus and Mercury play the part of "evening stars" this month. At the beginning of the month they appear low on the western horizon.

The Moon itself joins the pair from March 18th through the 20th. 

The Moon skims by the Pleiades star cluster and Taurus's bright red star Aldebaran on the next few evenings, March 21 through the 23rd.

Jupiter, king of the planets, rises just before midnight this month and earlier by month end. 

Even through the smallest telescope or average binoculars, you should see the 4 Galilean moons, Europa, Io, Callisto and Ganymede.

The March morning sky offers dazzling views of Mars and Saturn all month long.

Through a telescope, you can almost make out some of the surface features on Mars.

Look a little farther into Mars' future and circle May 5th with a red marker. When our InSight spacecraft launches for its 6 month journey to the Red Planet, Mars will be easily visible to your unaided eye. 

Keep watching Mars as it travels closer to Earth. It will be closest in late July, when the red planet will appear larger in apparent diameter than it has since 2003!

You are in for a real treat if you can get away to a dark sky location on a moonless night this month -- the Zodiacal Light and the Milky Way intersect! 

The Zodiacal light is a faint triangular glow seen from a dark sky just after sunset in the spring or just before sunrise in the fall.

The more familiar Milky Way is one of the spiral arms of our galaxy. 

What we're seeing is sunlight reflecting off dust grains that circle the Sun in the inner solar system. These dust grains journey across our sky in the ecliptic, the same plane as the Moon and the planets.

Watch the full What’s Up for March Video: 

There are so many sights to see in the sky. To stay informed, subscribe to our What’s Up video series on Facebook. Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.   

What’s Up - February 2018

What’s Up For February?

This month, in honor of Valentine's Day, we'll focus on celestial star pairs and constellation couples.

Let's look at some celestial pairs!

The constellations Perseus and Andromeda are easy to see high overhead this month.

According to lore, the warrior Perseus spotted a beautiful woman--Andromeda--chained to a seaside rock. After battling a sea serpent, he rescued her. 

As a reward, her parents Cepheus and Cassiopeia allowed Perseus to marry Andromeda.

The great hunter Orion fell in love with seven sisters, the Pleiades, and pursued them for a long time. Eventually Zeus turned both Orion and the Pleiades into stars.

Orion is easy to find. Draw an imaginary line through his belt stars to the Pleiades, and watch him chase them across the sky forever.

A pair of star clusters is visible on February nights. The Perseus Double Cluster is high in the sky near Andromeda's parents Cepheus and Cassiopeia.

Through binoculars you can see dozens of stars in each cluster. Actually, there are more than 300 blue-white supergiant stars in each of the clusters.

There are some colorful star pairs, some visible just by looking up and some requiring a telescope. Gemini's twins, the brothers Pollux and Castor, are easy to see without aid.

Orion's westernmost, or right, knee, Rigel, has a faint companion. The companion, Rigel B, is 500 times fainter than the super-giant Rigel and is visible only with a telescope. 

Orion's westernmost belt star, Mintaka, has a pretty companion. You'll need a telescope.

Finally, the moon pairs up with the Pleiades on the 22nd and with Pollux and Castor on the 26th.

Watch the full What’s Up for February Video: 

There are so many sights to see in the sky. To stay informed, subscribe to our What’s Up video series on Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.  

Much of the western United States began the morning with the view of a super blue blood moon total lunar eclipse. In this silent time lapse video, the complete eclipse is seen over NASA's Jet Propulsion Laboratory, located at the base of the San Gabriel Mountains near Pasadena, California.  This Jan. 31 full moon was special for three reasons: it was the third in a series of “supermoons,” when the Moon is closer to Earth in its orbit -- known as perigee -- and about 14 percent brighter than usual. It was also the second full moon of the month, commonly known as a “blue moon.” The super blue moon will pass through Earth’s shadow to give viewers in the right location a total lunar eclipse. While the Moon is in the Earth’s shadow it will take on a reddish tint, known as a “blood moon.”

Credits: NASA/JPL-Caltech

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.  

A Total Lunar Eclipse is Coming: 10 Things to Know

If you were captivated by August's total solar eclipse, there's another sky show to look forward to on Jan. 31: a total lunar eclipse!

Below are 10 things to know about this astronomical event, including where to see it, why it turns the Moon into a deep red color and more...

1. First things first. What's the difference between solar and lunar eclipses? We've got the quick and easy explanation in this video:

2. Location, location, location. What you see will depend on where you are. The total lunar eclipse will favor the western U.S., Alaska, Hawaii, and British Columbia on Jan. 31. Australia and the Pacific Ocean are also well placed to see a major portion of the eclipse, if not all of it.

3. Color play. So, why does the Moon turn red during a lunar eclipse? Here's your answer:

4. Scientists, stand by. What science can be done during a lunar eclipse? Find out HERE. 

5. Show and tell. What would Earth look like from the Moon during a lunar eclipse? See for yourself with this artist's concept HERE. 

6. Ask me anything. Mark your calendars to learn more about the Moon during our our Reddit AMA happening Monday, Jan. 29, from 3-4 pm EST/12-1 pm PST.

7. Social cues. Make sure to follow @NASAMoon and @LRO_NASA for all of the latest Moon news leading up to the eclipse and beyond.

8. Watch year-round. Can't get enough of observing the Moon? Make a DIY Moon Phases Calendar and Calculator that will keep all of the dates and times for the year's moon phases right at your fingertips HERE.

Then, jot down notes and record your own illustrations of the Moon with a Moon observation journal, available to download and print from moon.nasa.gov.

9. Lesson learned. For educators, pique your students' curiosities about the lunar eclipse with this Teachable Moment HERE.

10. Coming attraction. There will be one more lunar eclipse this year on July 27, 2018. But you might need your passport—it will only be visible from central Africa and central Asia. The next lunar eclipse that can be seen all over the U.S. will be on Jan. 21, 2019. It won't be a blue moon, but it will be a supermoon.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.  

What’s Up - January 2018

What’s Up For January? 

Quadrantid meteors, a West Coast-favoring total lunar eclipse and time to start watching Mars!

This month the new year's first meteor shower fizzles, Mars meets Jupiter in the morning sky and the U.S. will enjoy a total lunar eclipse!

Most meteor showers radiate from recognizable constellations. Like the Leonids, Geminids and Orionids.

But the Quadrantids are meteors that appear to radiate from the location of the former Quadrans Muralis constellation, an area that's now part of the constellation Bootes.

The Quadrantids' peak lasts for just a few hours, and sadly, this year their timing coincides with a very bright, nearly full moon that will wash out most of the meteors.

You can look in any direction to see all the meteor showers. When you see one of these meteors, hold a shoestring along the path it followed. The shoestring will lead you back to the constellation containing the meteor’s origin.

On the morning of January 6th, look in the south-southeast sky 45 minutes before sunrise to see Jupiter and fainter Mars almost as close as last month's Jupiter and Venus close pairing.

Mars is only one-sixth the apparent diameter of Jupiter, but the two offer a great binocular and telescopic view with a pretty color contrast. They remain in each other's neighborhood from January 5th through the 8th.

Finally, to end the month, a great total lunar eclipse favors the western U.S., Alaska, and Hawaii and British Columbia on January 31st. Australia and the Pacific Ocean are well placed to see a major portion of the eclipse--if not all of it.

Watch the full What’s Up for January Video: 

There are so many sights to see in the sky. To stay informed, subscribe to our What’s Up video series on Facebook. Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.   

The Moon in Motion

Happy New Year! And happy supermoon! Tonight, the Moon will appear extra big and bright to welcome us into 2018 – about 6% bigger and 14% brighter than the average full Moon. And how do we know that? Well, each fall, our science visualizer Ernie Wright uses data from the Lunar Reconnaissance Orbiter (LRO) to render over a quarter of a million images of the Moon. He combines these images into an interactive visualization, Moon Phase and Libration, which depicts the Moon at every day and hour for the coming year. 

Want to see what the Moon will look like on your birthday this year? Just put in the date, and even the hour (in Universal Time) you were born to see your birthday Moon.

Our Moon is quite dynamic. In addition to Moon phases, our Moon appears to get bigger and smaller throughout the year, and it wobbles! Or at least it looks that way to us on Earth. This wobbling is called libration, from the Latin for ‘balance scale’ (libra). Wright relies on LRO maps of the Moon and NASA orbit calculations to create the most accurate depiction of the 6 ways our Moon moves from our perspective.

1. Phases

The Moon phases we see on Earth are caused by the changing positions of the Earth and Moon relative to the Sun. The Sun always illuminates half of the Moon, but we see changing shapes as the Moon revolves around the Earth. Wright uses a software library called SPICE to calculate the position and orientation of the Moon and Earth at every moment of the year. With his visualization, you can input any day and time of the year and see what the Moon will look like!

2. Shape of the Moon

Check out that crater detail! The Moon is not a smooth sphere. It’s covered in mountains and valleys and thanks to LRO, we know the shape of the Moon better than any other celestial body in the universe. To get the most accurate depiction possible of where the sunlight falls on the lunar surface throughout the month, Wright uses the same graphics software used by Hollywood design studios, including Pixar, and a method called ‘raytracing’ to calculate the intricate patterns of light and shadow on the Moon’s surface, and he checks the accuracy of his renders against photographs of the Moon he takes through his own telescope.

3. Apparent Size 

The Moon Phase and Libration visualization shows you the apparent size of the Moon. The Moon’s orbit is elliptical, instead of circular - so sometimes it is closer to the Earth and sometimes it is farther. You’ve probably heard the term “supermoon.” This describes a full Moon at or near perigee (the point when the Moon is closest to the Earth in its orbit). A supermoon can appear up to 14% bigger and brighter than a full Moon at apogee (the point when the Moon is farthest from the Earth in its orbit). 

Our supermoon tonight is a full Moon very close to perigee, and will appear to be about 14% bigger than the July 27 full Moon, the smallest full Moon of 2018, occurring at apogee. Input those dates into the Moon Phase and Libration visualization to see this difference in apparent size!

4. East-West Libration

Over a month, the Moon appears to nod, twist, and roll. The east-west motion, called ‘libration in longitude’, is another effect of the Moon’s elliptical orbital path. As the Moon travels around the Earth, it goes faster or slower, depending on how close it is to the Earth. When the Moon gets close to the Earth, it speeds up thanks to an additional pull from Earth’s gravity. Then it slows down, when it’s farther from the Earth. While this speed in orbital motion changes, the rotational speed of the Moon stays constant. 

This means that when the Moon moves faster around the Earth, the Moon itself doesn’t rotate quite enough to keep the same exact side facing us and we get to see a little more of the eastern side of the Moon. When the Moon moves more slowly around the Earth, its rotation gets a little ahead, and we see a bit more of its western side.

5. North-South Libration

The Moon also appears to nod, as if it were saying “yes,” a motion called ‘libration in latitude’. This is caused by the 5 degree tilt of the Moon’s orbit around the Earth. Sometimes the Moon is above the Earth’s northern hemisphere and sometimes it’s below the Earth’s southern hemisphere, and this lets us occasionally see slightly more of the northern or southern hemispheres of the Moon! 

6. Axis Angle

Finally, the Moon appears to tilt back and forth like a metronome. The tilt of the Moon’s orbit contributes to this, but it’s mostly because of the 23.5 degree tilt of our own observing platform, the Earth. Imagine standing sideways on a ramp. Look left, and the ramp slopes up. Look right and the ramp slopes down. 

Now look in front of you. The horizon will look higher on the right, lower on the left (try this by tilting your head left). But if you turn around, the horizon appears to tilt the opposite way (tilt your head to the right). The tilted platform of the Earth works the same way as we watch the Moon. Every two weeks we have to look in the opposite direction to see the Moon, and the ground beneath our feet is then tilted the opposite way as well.

So put this all together, and you get this:

Beautiful isn’t it? See if you can notice these phenomena when you observe the Moon. And keep coming back all year to check on the Moon’s changing appearance and help plan your observing sessions.

Follow @NASAMoon on Twitter to keep up with the latest lunar updates. 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

What Scientists Are Learning from the Eclipse

While millions of people in North America headed outside to watch the eclipse on Aug. 21, 2017, hundreds of scientists got out telescopes, set up instruments, and prepared balloon launches – all so they could study the Sun and its complicated influence on Earth.

Total solar eclipses happen about once every 18 months somewhere in the world, but the August eclipse was rare because of its long path over land. The total eclipse lasted more than 90 minutes over land, from when it first reached Oregon to when it left the U.S. in South Carolina.

This meant that scientists could collect more data from land than during most eclipses, giving us new insight into our world and the star that powers it.

A moment in the Sun’s atmosphere

During a total solar eclipse, the Sun’s outer atmosphere, the corona, is visible from Earth. It’s normally too dim to see next to the Sun’s bright face, but, during an eclipse, the Moon blocks out the Sun, revealing the corona.

Image Credit: Peter Aniol, Miloslav Druckmüller and Shadia Habbal

Though we can study parts of the corona with instruments that create artificial eclipses, some of the innermost regions of the corona are only visible during total solar eclipses. Solar scientists think this part of the corona may hold the secrets to some of our most fundamental questions about the Sun: Like how the solar wind – the constant flow of magnetized material that streams out from the Sun and fills the solar system – is accelerated, and why the corona is so much hotter than the Sun’s surface below.  

Depending on where you were, someone watching the total solar eclipse on Aug. 21 might have been able to see the Moon completely obscuring the Sun for up to two minutes and 42 seconds. One scientist wanted to stretch that even further – so he used a pair of our WB-57 jets to chase the path of the Moon’s shadow, giving their telescopes an uninterrupted view of the solar corona for just over seven and half minutes.

These telescopes were originally designed to help monitor space shuttle launches, and the eclipse campaign was their first airborne astronomy project!

These scientists weren’t the only ones who had the idea to stretch out their view of the eclipse: The Citizen CATE project (short for Continental-America Telescopic Eclipse) did something similar, but with the help of hundreds of citizen scientists. 

Citizen CATE included 68 identical small telescopes spread out across the path of totality, operated by citizen and student scientists. As the Moon’s shadow left one telescope, it reached the next one in the lineup, giving scientists a longer look at the way the corona changes throughout the eclipse.

After accounting for clouds, Citizen CATE telescopes were able to collect 82 minutes of images, out of the 93 total minutes that the eclipse was over the US. Their images will help scientists study the dynamics of the inner corona, including fast solar wind flows near the Sun’s north and south poles.

The magnetized solar wind can interact with Earth’s magnetic field, causing auroras, interfering with satellites, and – in extreme cases – even straining our power systems, and all these measurements will help us better understand how the Sun sends this material speeding out into space.

Exploring the Sun-Earth connection

Scientists also used the eclipse as a natural laboratory to explore the Sun’s complicated influence on Earth.

High in Earth’s upper atmosphere, above the ozone layer, the Sun’s intense radiation creates a layer of electrified particles called the ionosphere. This region of the atmosphere reacts to changes from both Earth below and space above. Such changes in the lower atmosphere or space weather can manifest as disruptions in the ionosphere that can interfere with communication and navigation signals.

One group of scientists used the eclipse to test computer models of the ionosphere’s effects on these communications signals. They predicted that radio signals would travel farther during the eclipse because of a drop in the number of energized particles. Their eclipse day data – collected by scientists spread out across the US and by thousands of amateur radio operators – proved that prediction right.

In another experiment, scientists used the Eclipse Ballooning Project to investigate the eclipse’s effects lower in the atmosphere. The project incorporated weather balloon flights from a dozen locations to form a picture of how Earth’s lower atmosphere – the part we interact with and which directly affects our weather – reacted to the eclipse. They found that the planetary boundary layer, the lowest part of Earth’s atmosphere, actually moved closer to Earth during the eclipse, dropped down nearly to its nighttime altitude.

A handful of these balloons also flew cards containing harmless bacteria to explore the potential for contamination of other planets with Earth-born life. Earth’s stratosphere is similar to the surface of Mars, except in one main way: the amount of sunlight. But during the eclipse, the level of sunlight dropped to something closer to what you’d expect to see on Mars, making this the perfect testbed to explore whether Earth microbes could hitch a ride to the Red Planet and survive. Scientists are working through the data collected, hoping to build up better information to help robotic and human explorers alike avoid carrying bacterial hitchhikers to Mars.

Image: The small metal card used to transport bacteria.

Finally, our EPIC instrument aboard NOAA’s DSCOVR satellite provided awe-inspiring views of the eclipse, but it’s also helping scientists understand Earth’s energy balance. Earth’s energy system is in a constant dance to maintain a balance between incoming radiation from the Sun and outgoing radiation from Earth to space, which scientists call the Earth’s energy budget. The role of clouds, both thick and thin, is important in their effect on energy balance.

Like a giant cloud, the Moon during the total solar eclipse cast a large shadow across a swath of the United States. Scientists know the dimensions and light-blocking properties of the Moon, so they used ground- and space-based instruments to learn how this large shadow affects the amount of sunlight reaching Earth’s surface, especially around the edges of the shadow. Measurements from EPIC show a 10% drop in light reflected from Earth during the eclipse (compared to about 1% on a normal day). That number will help scientists model how clouds radiate the Sun’s energy – which drives our planet’s ocean currents, seasons, weather and climate – away from our planet.

For even more eclipse science updates, stay tuned to nasa.gov/eclipse.

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Finalists for a Future Mission to Explore the Solar System

We’ve selected two finalists for a robotic mission that is planned to launch in the mid-2020s! Following a competitive peer review process, these two concepts were chosen from 12 proposals that were submitted in April under a New Frontiers program announcement opportunity.

What are they?

In no particular order…

CAESAR

CAESAR, or the Comet Astrobiology Exploration Sample Return mission seeks to return a sample from 67P/Churyumov-Gerasimenko – the comet that was successfully explored by the European Space Agency’s Rosetta spacecraft – to determine its origin and history.

This mission would acquire a sample from the nucleus of comet Churyumov-Gerasimenko and return it safely to Earth. 

Comets are made up of materials from ancient stars, interstellar clouds and the birth of our solar system, so the CAESAR sample could reveal how these materials contributed to the early Earth, including the origins of the Earth's oceans, and of life.

Dragonfly

A drone-like rotorcraft would be sent to explore the prebiotic chemistry and habitability of dozens of sites on Saturn’s moon Titan – one of the so-called ocean worlds in our solar system.

Unique among these Ocean Worlds, Titan has a surface rich in organic compounds and diverse environments, including those where carbon and nitrogen have interacted with water and energy.

Dragonfly would be a dual-quadcopter lander that would take advantage of the environment on Titan to fly to multiple locations, some hundreds of miles apart, to sample materials and determine surface composition to investigate Titan's organic chemistry and habitability, monitor atmospheric and surface conditions, image landforms to investigate geological processes, and perform seismic studies.

What’s Next?

The CAESAR and Dragonfly missions will receive funding through the end of 2018 to further develop and mature the concepts. It is planned that from these, one investigation will be chosen in the spring of 2019 to continue into subsequent mission phases.

That mission would be the fourth mission in the New Frontiers portfolio, which conducts principal investigator (PI)-led planetary science missions under a development cost cap of approximately $850 million. Its predecessors are the New Horizons mission to Pluto and a Kuiper Belt object, the Juno mission to Jupiter and OSIRIS-REx, which will rendezvous with and return a sample of the asteroid Bennu. 

Key Technologies

We also announced that two mission concepts were chosen to receive technology development funds to prepare them for future mission opportunities.

The Enceladus Life Signatures and Habitability (ELSAH) mission concept will receive funds to enable life detection measurements by developing cost-effective techniques to limit spacecraft contamination on cost-capped missions.

The Venus In situ Composition Investigations (VICI) mission concept will further develop the VEMCam instrument to operate under harsh conditions on Venus. The instrument uses lasers on a lander to measure the mineralogy and elemental composition of rocks on the surface of Venus.

The call for these mission concepts occurred in April and was limited to six mission themes: comet surface sample return, lunar south pole-Aitken Basin sample return, ocean worlds, Saturn probe, Trojan asteroid tour and rendezvous and Venus insitu explorer.

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Human Expansion Across Solar System

On this day in 1972, two NASA astronauts landed on the Moon. Now, 45 years later, we have been instructed to return to the lunar surface.

Today at the White House, President Trump signed the Space Policy Directive 1, a change in national space policy that provides for a U.S.-led program with private sector partners for a human return to the Moon, followed by missions to Mars and beyond.

Among other dignitaries on hand for the signing, were NASA astronauts Sen. Harrison “Jack” Schmitt, Buzz Aldrin, Peggy Whitson and Christina Koch.

Schmitt landed on the moon 45 years to the minute that the policy directive was signed as part of our Apollo 17 mission, and is the most recent living person to have set foot on our lunar neighbor. 

Above, at the signing ceremony instructing us to send humans back to the lunar surface, Schmitt shows First Daughter Ivanka Trump the Moon sample he collected in 1972.

The effort signed today will more effectively organize government, private industry and international efforts toward returning humans on the Moon, and will lay the foundation that will eventually enable human exploration of Mars.

To learn more, visit: https://www.nasa.gov/press-release/new-space-policy-directive-calls-for-human-expansion-across-solar-system

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Reinventing the Wheel

Planning a trip to the Moon? Mars? You’re going to need good tires…

Exploration requires mobility. And whether you’re on Earth or as far away as the Moon or Mars, you need good tires to get your vehicle from one place to another. Our decades-long work developing tires for space exploration has led to new game-changing designs and materials. Yes, we’re reinventing the wheel—here’s why.

Wheels on the Moon

Early tire designs were focused on moving hardware and astronauts across the lunar surface. The last NASA vehicle to visit the Moon was the Lunar Roving Vehicle during our Apollo missions. The vehicle used four large flexible wire mesh wheels with stiff inner frames. We used these Apollo era tires as the inspiration for new designs using newer materials and technology to better function on a lunar surface.

Up springs a new idea

During the mid-2000s, we worked with industry partner Goodyear to develop the Spring Tire, an airless compliant tire that consists of several hundred coiled steel wires woven into a flexible mesh, giving the tires the ability to support high loads while also conforming to the terrain. The Spring Tire has been proven to generate very good traction and durability in soft sand and on rocks.

Spring Tires for Mars

A little over a year after the Mars Curiosity Rover landed on Mars, engineers began to notice significant wheel damage in 2013 due to the unexpectedly harsh terrain. That’s when engineers began developing new Spring Tire prototypes to determine if they would be a new and better solution for exploration rovers on Mars.

In order for Spring Tires to go the distance on Martian terrain, new materials were required. Enter nickel titanium, a shape memory alloy with amazing capabilities that allow the tire to deform down to the axle and return to its original shape.

These tires can take a lickin’

After building the shape memory alloy tire, Glenn engineers sent it to the Jet Propulsion Laboratory’s Mars Life Test Facility. It performed impressively on the punishing track.

Why reinvent the wheel? It’s worth it.

New, high performing tires would allow lunar and Mars rovers to explore greater regions of the surface than currently possible. They conform to the terrain and do not sink as much as rigid wheels, allowing them to carry heavier payloads for the same given mass and volume. Also, because they absorb energy from impacts at moderate to high speeds, there is potential for use on crewed exploration vehicles which are expected to move at speeds significantly higher than the current Mars rovers.

Airless tires on Earth

Maybe. Recently, engineers and materials scientists have been testing a spinoff tire version that would work on cars and trucks on Earth. Stay tuned as we continue to push the boundaries on traditional concepts for exploring our world and beyond.  

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What’s That in the Night Sky?

The night sky has really been showing off lately. During the past week, we’ve had the chance to see some amazing sights by simply just looking up!

On Wednesday, Dec. 29, we were greeted by a flyby of the International Space Station over much of the east coast.

When the space station flies overhead, it’s usually easy to spot because it’s the third brightest object in the night sky. You can even enter your location into THIS website and get a list of dates/times when it will be flying over you!

One of our NASA Headquarters Photographers ventured to the Washington National Cathedral to capture the pass in action.

Then, on Saturday, Dec. 2, just one day before the peak of this month’s supermoon, the space station was seen passing in front of the Moon. 

Captured by another NASA HQ Photographer, this composite image shows the space station, with a crew of six onboard, as its silhouette transits the Moon at roughly five miles per second.

Here’s an animated version of the transit.

To top off all of this night sky greatness, are these beautiful images of the Dec. 3 supermoon. This marked the first of three consecutive supermoons taking the celestial stage. The two others will occur on Jan. 1 and Jan. 31, 2018.

A supermoon occurs when the moon’s orbit is closest to Earth at the same time that it is full.

Are you this pilot? An aircraft taking off from Ronald Reagan National Airport is seen passing in front of the Moon as it rose on Sunday.

Learn more about the upcoming supermoons: 

To learn more about what you can expect to spot in the sky this month, visit: https://solarsystem.nasa.gov/news/2017/12/04/whats-up-december-2017

Discover when the International Space Station will be visible over your area by visiting: https://spotthestation.nasa.gov/

Learn more about our Moon at: https://moon.nasa.gov/

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What’s Up November 2017

What’s Up For November?

Dawn pairing of Jupiter and Venus, Moon shines near star clusters, meteor activity all month long!

This month binoculars will come in handy--to view the moon, star clusters, and a close pairing of Venus and Jupiter.

You can’t miss bright Venus in the predawn sky. This month Venus pairs up with Jupiter on the morning of November 13th.

The Leonids peak on a moonless November 17th. Expect no more than 10 meteors an hour around 3:00 a.m., the height of the shower.

The Northern and Southern sub-branches of the Taurid meteor shower offer sparse counts of about 5 meteors per hour, but slow, bright meteors are common.

The nearby November Orionids peak on the 28th. In contrast to the Taurids, the Orionids are swift. But don’t expect more than 3 meteors per hour.

The moon glides by three beautiful star clusters in the morning sky this month, and a pair of binoculars will allow you to see the individual stars in the clusters. Aim your binoculars at the Pleiades and the moon on the 5th.

Then aim at the Messier or M-35 cluster and the moon on the 7th and the Beehive cluster and the moon on the 10th.

Meanwhile, at dusk, catch Saturn as it dips closer to the western horizon and pairs up with Mercury on the 24th through the 28th.

Also, Comet C/2017 O1 should still be a binocular-friendly magnitude 7 or 8 greenish object in November. Use Polaris, the North Star as a guide. Look in the East to Northeast sky in the late evening.  

Watch the full What’s Up for November Video: 

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5 things that may surprise you about the Moon

...In honor of International Observe the Moon Night

October 28th is International Observe the Moon Night, a worldwide, public celebration of lunar science and exploration held annually since 2010 thanks to our Lunar Reconnaissance Orbiter (LRO) mission team and partners. One day each year, everyone on Earth is invited to observe and learn about the Moon together, and to celebrate the cultural and personal connections we all have with our planet’s nearest neighbor.

Here are 5 things that might surprise you about the Moon.

1. There has been a spacecraft there for 100 lunar days

In October 2017, LRO celebrates one hundred days of collecting scientific data at the Moon. One hundred Moon days. From our perspective on Earth, one lunar day is one full phase cycle, or about 29.5 Earth days. That's 100 opportunities to observe changes from night to day, photograph the surface at different Sun angles, measure rising and falling temperatures, study the way certain chemicals react to the daily light and temperature cycle, and increase our understanding of the Moon as a dynamic place.

2. You can still see the paths left by Apollo astronauts’ boot prints and rovers

Much of the lunar surface is covered in very fine dust. When Apollo astronauts landed on the Moon, the descent stage engine disturbed the dust and produced a distinct bright halo around the lunar module. As astronauts moved around, their tracks exposed the darker soil underneath, creating distinct trails that we know, thanks to LRO, are still visible today. The Moon has no atmosphere, so there is no wind to wipe away these tracks.

3. The Moon has tattoos!

Observations from LRO show mysterious patterns of light and dark that are unique to the Moon. These lunar swirls look painted on, like the Moon got ‘inked.’ Lunar swirls, like these imaged at Reiner Gamma by LRO, are found at more than 100 locations across the lunar surface. Lunar swirls can be tens of miles across and appear in groups or as isolated features. 

Researchers think these patterns form in places where there’s still a remnant of the Moon’s magnetic field. There are still many competing theories about how swirls form, but the primary idea is that the local magnetic field deflects the energetic particles in the solar wind, so there’s not as much weathering of the surface. The magnetically shielded areas would then look brighter than everything around them.

4. There were once active volcanoes, that shaped what we see now

Early astronomers named the large dark spots that we see on the near side of the Moon “maria,” Latin for “seas,” because that’s what they thought they were. We now know that the dark spots are cooled lava, called basalt, formed from ancient volcanic eruptions. The Moon’s volcanoes are no longer active, but their past shapes the Moon that we see today. The Moon doesn’t have large volcanoes like ones in Hawaii, but it does have smaller cones and domes. 

Other small features derived from volcanic activity include rivers of dried lava flows, like the ones visible in this image of Vallis Schroteri taken by LRO, and dark areas formed from eruptive volcanoes that spewed fire. For many years, scientists thought the Moon’s volcanic activity died out long ago, but there’s some evidence for relatively “young” volcanism, suggesting that the activity gradually slowed down instead of stopping abruptly.

5. Anyone, anywhere can participate in International Observe the Moon Night.  

How to celebrate International Observe the Moon Night

Attend an event –  See where events are happening near you by visiting http://observethemoonnight.org

Host an event – Call up your neighbors and friends and head outdoors – no special equipment is needed. Let us know how you celebrated by registering your event!

Don’t let cloudy weather get you down! Observe the Moon in a variety of ways from the comfort of indoors – View stunning lunar vistas through images and videos, or explore the Moon on your own with QuickMap or Moon Trek

Join the worldwide conversation with #ObserveTheMoon on Twitter, Instagram and Facebook

For regular Moon-related facts, updates and science, follow @NASAMoon on Twitter

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Solar System: Things To Know This Week

Weather permitting, you can observe the Moon most nights, unless it's a new moon, when the lighted side of the Moon faces away from Earth. The Moon is by far the brightest object in the night sky and there's plenty to see. But this week is special...

...October 28 is International Observe the Moon Night (also known as InOMN).

Here's all you need to know to join in and celebrate:

1. One Planet. One Moon. One Night.

Everyone on Earth is invited to join the celebration by hosting or attending an InOMN event and uniting on one day each year to look at and learn about the Moon together.

2. What's Up?

October's night skies are full of sights, from the first quarter Moon on InOMN to Saturn making a cameo appearance above the Moon October 23 and 24. Watch our What's Up video for details.

3. Be Social

Hundreds of events are planned around the globe. Click the top link on this page for a handy map. You can also register your own event.

4. Don't Just Stand There

Here are some activities for enhanced Moon watching.

5. Impress Your Friends with Moon Knowledge

Download InOMN flyers and handouts, Moon maps and even some pre-made presentations. There's even a certificate to mark your participation.

6. Guide to the Face of the Moon

Almost dead center on the Earth-facing side of the Moon is the Surveyor 6 robotic spacecraft impact side. Apollo 12 and 14 are a bit to the left. And Apollo 11 - the first steps on the moon - are to the right. This retro graphic tells the whole story.

7. Moon Shots

NASA photographers have done some exceptional work capturing views of the Moon from Earth. Here are a few galleries:

You can't have a solar eclipse without the Moon.

The 2016 "Supermoon" was pretty spectacular.

The Moon gets eclipsed, too.

That IS a Moon - AND the International Space Station.

The Moon is always a great photo subject.

Some spooky shots of the 2014 "Supermoon."

And 2013.

Tips from a NASA pro for photographing the Moon.

8. Walking on the Moon

Twelve human beings walked on the face of the Moon. Here are some of the best shots from the Apollo program.

9. Moon Watch

Our Lunar Reconnaissance Orbiter is up there right now, mapping the moon and capturing some spectacular high-resolution shots.

10. Keep Exploring

Make our Moon portal your base for further lunar exploration.

Check out the full version of ‘Ten Things to Know This Week’ HERE.

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Solar System: 10 Things to Know This Week

Need some space? 

Here are 10 perspective-building images for your computer desktop and mobile device wallpaper. 

These are all real images, sent very recently by our planetary missions throughout the solar system. 

1. Our Sun

Warm up with this view from our Solar Dynamics Observatory showing active regions on the Sun in October 2017. They were observed in a wavelength of extreme ultraviolet light that reveals plasma heated to over a million degrees. 

Downloads  Desktop: 1280 x 800 | 1600 x 1200 | 1920 x 1200 Mobile: 1440 x 2560 | 1080 x 1920 | 750 x 1334

2. Jupiter Up-Close

This series of enhanced-color images shows Jupiter up close and personal, as our Juno spacecraft performed its eighth flyby of the gas giant planet on Sept. 1, 2017. 

Downloads Desktop: 1280 x 800 | 1600 x 1200 | 1920 x 1200 Mobile: 1440 x 2560  | 1080 x 1920 | 750 x 1334

3. Saturn’s and Its Rings

With this mosaic from Oct. 28, 2016, our Cassini spacecraft captured one of its last looks at Saturn and its main rings from a distance. 

Downloads Desktop: 1280 x 800 | 1600 x 1200 | 1920 x 1200 Mobile: 1440 x 2560 | 1080 x 1920 | 750 x 1334

4. Gale Crater on Mars

This look from our Curiosity Mars rover includes several geological layers in Gale crater to be examined by the mission, as well as the higher reaches of Mount Sharp beyond. The redder rocks of the foreground are part of the Murray formation. Pale gray rocks in the middle distance of the right half of the image are in the Clay Unit. A band between those terrains is "Vera Rubin Ridge," where the rover is working currently. The view combines six images taken with the rover's Mast Camera (Mastcam) on Jan. 24, 2017. 

Downloads Desktop: 1280 x 800 | 1600 x 1200 | 1920 x 1200 Mobile: 1440 x 2560 | 1080 x 1920 | 750 x 1334

5. Sliver of Saturn

Cassini peers toward a sliver of Saturn's sunlit atmosphere while the icy rings stretch across the foreground as a dark band on March 31, 2017. This view looks toward the unilluminated side of the rings from about 7 degrees below the ring plane. 

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6. Dwarf Planet Ceres 

This image of the limb of dwarf planet Ceres shows a section of the northern hemisphere, as seen by our Dawn mission. Prominently featured is Occator Crater, home of Ceres' intriguing "bright spots." The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below. 

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7. Martian Crater

This image from our Mars Reconnaissance Orbiter (MRO) shows a crater in the region with the most impressive known gully activity in Mars' northern hemisphere. Gullies are active in the winter due to carbon dioxide frost, but northern winters are shorter and warmer than southern winters, so there is less frost and less gully activity. 

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8. Dynamic Storm on Jupiter

A dynamic storm at the southern edge of Jupiter's northern polar region dominates this Jovian cloudscape, courtesy of Juno. This storm is a long-lived anticyclonic oval named North North Temperate Little Red Spot 1. Citizen scientists Gerald Eichstädt and Seán Doran processed this image using data from the JunoCam imager. 

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9. Rings Beyond Saturn’s Sunlit Horizon 

This false-color view from the Cassini spacecraft gazes toward the rings beyond Saturn's sunlit horizon. Along the limb (the planet's edge) at left can be seen a thin, detached haze. 

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10. Saturn’s Ocean-Bearing Moon Enceladus

Saturn's active, ocean-bearing moon Enceladus sinks behind the giant planet in a farewell portrait from Cassini. This view of Enceladus was taken by NASA's Cassini spacecraft on Sept. 13, 2017. It is among the last images Cassini sent back before its mission came to an end on Sept. 15, after nearly 20 years in space. 

Downloads Desktop: 1280 x 800 | 1600 x 1200 | 1920 x 1200 Mobile: 1440 x 2560 | 1080 x 1920 | 750 x 1334

Applying Wallpaper: 1. Click on the screen resolution you would like to use. 2. Right-click on the image (control-click on a Mac) and select the option 'Set the Background' or 'Set as Wallpaper' (or similar).

Places to look for more of our pictures include solarsystem.nasa.gov/galleries, images.nasa.gov and www.jpl.nasa.gov/spaceimages.

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Chasing the Shadow of Neptune’s Moon Triton

Our Flying Observatory

Our flying observatory, called SOFIA, carries a 100-inch telescope inside a Boeing 747SP aircraft. Scientists onboard study the life cycle of stars, planets (including the atmosphere of Mars and Jupiter), nearby planetary systems, galaxies, black holes and complex molecules in space.

AND on Oct. 5, SOFIA is going on a special flight to chase the shadow of Neptune's moon Triton as it crosses Earth’s surface!

In case you’re wondering, SOFIA stands for: Stratospheric Observatory for Infrared Astronomy.

Triton

Triton is 1,680 miles (2,700 km) across, making it the largest of the 13 moons orbiting Neptune. Unlike most large moons in our solar system, Triton orbits in the opposite direction of Neptune, called a retrograde orbit. This backward orbit leads scientists to believe that Triton formed in an area past Neptune, called the Kuiper Belt, and was pulled into its orbit around Neptune by gravity. 

The Voyager 2 spacecraft flew past Neptune and Triton in 1989 and found that Triton’s atmosphere is made up of mostly nitrogen...but it has not been studied in nearly 16 years!

Occultations are Eclipse-Like Events

An occultation occurs when an object, like a planet or a moon, passes in front of a star and completely blocks the light from that star. As the object blocks the star’s light, it casts a faint shadow on Earth’s surface. 

But unlike an eclipse, these shadows are not usually visible to the naked eye because the star and object are much smaller and not nearly as bright as our sun. Telescopes with special instruments can actually see these shadows and study the star’s light as it passes near and around the object – if they can be in the right place on Earth to catch the shadow.

Chasing Shadows

Scientists have been making advanced observations of Triton and a background star. They've calculated exactly where Triton’s faint shadow will fall on Earth! Our SOFIA team has designed a flight path that will put SOFIA (the telescope and aircraft) exactly in the center of the shadow at the precise moment that Triton and the star will align. 

This is no easy feat because the shadow is moving at more than 53,000 mph while SOFIA flies at Mach 0.85 (652 mph), so we only have about two minutes to catch the shadow!! But our SOFIA team has previously harnessed the aircraft’s mobility to study Pluto from inside the center of its occultation shadow, and is ready to do it again to study Triton!

What We Learn From Inside the Shadow

From inside the shadow, our team on SOFIA will study the star’s light as it passes around and through Triton’s atmosphere. This allows us to learn more about Triton’s atmosphere, including its temperature, pressure, density and composition! 

Our team will use this information to examine if Triton’s atmosphere has changed since our Voyager 2 spacecraft flew past it in 1989. That’s a lot of information from a bit of light inside a shadow! Similar observations of Uranus in 1977, from our previous flying observatory, led to the discovery of rings around that planet!

International Ground-Based Support

Ground-based telescopes across the United States and Europe – from Scotland to the Canary Islands – will also be studying Triton’s occultation. Even though most of these telescopes will not be in the center of the shadow, the simultaneous observations, from different locations on Earth, will give us information about how Triton’s atmosphere varies across its latitudes. 

This data from across the Earth and from onboard SOFIA will help researchers understand how Triton’s atmosphere is distorted at different locations by its high winds and its strong tides!

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What’s Up October 2017

What’s Up For October? 

Planet Pairs, Stellar Superstars, Observe The Moon Night!!

This month, catch planet pairs, our moon near red stars, an asteroid, meteors and International Observe the Moon Night!

You can't miss bright Venus in the predawn sky. Look for fainter Mars below Venus on the 1st, really close on the 5th, and above Venus after that.

Midmonth, the moon is visible near Regulus, the white starry heart of the constellation Leo.

In the October 8-11 predawn sky watch the moon glide near the Pleiades star cluster and pass near the red stars Aldebaran in the constellation Taurus and Betelgeuse in Orion.

After dusk in the early part of the month look for Saturn in the southwest sky above another red star: Antares in Scorpius. Later in the month, find the moon above Antares October 22 and 23.

Saturn will be above the moon on the 23rd and below it on the 24th.

Uranus reach opposition on October 19th. It's visible all night long and its blue-green color is unmistakeable. It may be bright enough to see with your naked eye--and for sure in binoculars.

The Orionids peak on October 20--a dark, moonless night. Look near Orion's club in the hours before dawn and you may see up to 10 to 15 meteors per hour.

Use binoculars to look for bright asteroid 7 Iris in the constellation Aries. Newbies to astronomy should be able to spot this magnitude 6.9 asteroid - even from the city. 

Look later in the month and sketch its positions a day or two apart--to see it move.

Finally, celebrate International Observe the Moon Night on October 28 with your local astronomy club, Solar System Ambassador, museum, or planetarium. The first quarter moon that night will display some great features!

Watch the full What’s Up for October Video: 

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Cassini Spacecraft: Top Discoveries

Our Cassini spacecraft has been exploring Saturn, its stunning rings and its strange and beautiful moons for more than a decade.

Having expended almost every bit of the rocket propellant it carried to Saturn, operators are deliberately plunging Cassini into the planet to ensure Saturn’s moons will remain pristine for future exploration – in particular, the ice-covered, ocean-bearing moon Enceladus, but also Titan, with its intriguing pre-biotic chemistry.

Let’s take a look back at some of Cassini’s top discoveries:  

Titan

Under its shroud of haze, Saturn’s planet-sized moon Titan hides dunes, mountains of water ice and rivers and seas of liquid methane. Of the hundreds of moons in our solar system, Titan is the only one with a dense atmosphere and large liquid reservoirs on its surface, making it in some ways more like a terrestrial planet.

Both Earth and Titan have nitrogen-dominated atmospheres – over 95% nitrogen in Titan’s case. However, unlike Earth, Titan has very little oxygen; the rest of the atmosphere is mostly methane and traced amounts of other gases, including ethane.

There are three large seas, all located close to the moon’s north pole, surrounded by numerous smaller lakes in the northern hemisphere. Just one large lake has been found in the southern hemisphere.

Enceladus

The moon Enceladus conceals a global ocean of salty liquid water beneath its icy surface. Some of that water even shoots out into space, creating an immense plume!

For decades, scientists didn’t know why Enceladus was the brightest world in the solar system, or how it related to Saturn’s E ring. Cassini found that both the fresh coating on its surface, and icy material in the E ring originate from vents connected to a global subsurface saltwater ocean that might host hydrothermal vents.

With its global ocean, unique chemistry and internal heat, Enceladus has become a promising lead in our search for worlds where life could exist.

Iapetus

Saturn’s two-toned moon Iapetus gets its odd coloring from reddish dust in its orbital path that is swept up and lands on the leading face of the moon.

The most unique, and perhaps most remarkable feature discovered on Iapetus in Cassini images is a topographic ridge that coincides almost exactly with the geographic equator. The physical origin of the ridge has yet to be explained...

It is not yet year whether the ridge is a mountain belt that has folded upward, or an extensional crack in the surface through which material from inside Iapetus erupted onto the surface and accumulated locally.

Saturn’s Rings

Saturn’s rings are made of countless particles of ice and dust, which Saturn’s moons push and tug, creating gaps and waves.

Scientists have never before studied the size, temperature, composition and distribution of Saturn’s rings from Saturn obit. Cassini has captured extraordinary ring-moon interactions, observed the lowest ring-temperature ever recorded at Saturn, discovered that the moon Enceladus is the source for Saturn’s E ring, and viewed the rings at equinox when sunlight strikes the rings edge-on, revealing never-before-seen ring features and details.

Cassini also studied features in Saturn’s rings called “spokes,” which can be longer than the diameter of Earth. Scientists think they’re made of thin icy particles that are lifted by an electrostatic charge and only last a few hours.  

Auroras

The powerful magnetic field that permeates Saturn is strange because it lines up with the planet’s poles. But just like Earth’s field, it all creates shimmering auroras.

Auroras on Saturn occur in a process similar to Earth’s northern and southern lights. Particles from the solar wind are channeled by Saturn’s magnetic field toward the planet’s poles, where they interact with electrically charged gas (plasma) in the upper atmosphere and emit light.  

Turbulent Atmosphere

Saturn’s turbulent atmosphere churns with immense storms and a striking, six-sided jet stream near its north pole.

Saturn’s north and south poles are also each beautifully (and violently) decorated by a colossal swirling storm. Cassini got an up-close look at the north polar storm and scientists found that the storm’s eye was about 50 times wider than an Earth hurricane’s eye.

Unlike the Earth hurricanes that are driven by warm ocean waters, Saturn’s polar vortexes aren’t actually hurricanes. They’re hurricane-like though, and even contain lightning. Cassini’s instruments have ‘heard’ lightning ever since entering Saturn orbit in 2004, in the form of radio waves. But it wasn’t until 2009 that Cassini’s cameras captured images of Saturnian lighting for the first time.

Cassini scientists assembled a short video of it, the first video of lightning discharging on a planet other than Earth.

Cassini’s adventure will end soon because it’s almost out of fuel. So to avoid possibly ever contaminating moons like Enceladus or Titan, on Sept. 15 it will intentionally dive into Saturn’s atmosphere.

The spacecraft is expected to lose radio contact with Earth within about one to two minutes after beginning its decent into Saturn’s upper atmosphere. But on the way down, before contact is lost, eight of Cassini’s 12 science instruments will be operating! More details on the spacecraft’s final decent can be found HERE.

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Eclipse 2017 From Space

On Aug. 21, 2017, a total solar eclipse passed over North America. People throughout the continent captured incredible images of this celestial phenomenon. We and our partner agencies had a unique vantage point on the eclipse from space. Here are a few highlights from our fleet of satellites that observe the Sun, the Moon and Earth.

Our Solar Dynamics Observatory, or SDO, which watches the Sun nearly 24/7 from its orbit 3,000 miles above Earth, saw a partial eclipse on Aug. 21.

SDO sees the Moon cross in front of the Sun several times a year. However, these lunar transits don’t usually correspond to an eclipse here on Earth, and an eclipse on the ground doesn’t guarantee that SDO will see anything out of the ordinary. In this case, on Aug. 21, SDO did see the Moon briefly pass in front of the Sun at the same time that the Moon’s shadow passed over the eastern United States. From its view in space, SDO only saw 14 percent of the Sun blocked by the Moon, while most U.S. residents saw 60 percent blockage or more.

Six people saw the eclipse from the International Space Station. Viewing the eclipse from orbit were NASA’s Randy Bresnik, Jack Fischer and Peggy Whitson, the European Space Agency’s Paolo Nespoli, and Roscosmos’ Commander Fyodor Yurchikhin and Sergey Ryazanskiy. The space station crossed the path of the eclipse three times as it orbited above the continental United States at an altitude of 250 miles.

From a million miles out in space, our Earth Polychromatic Imaging Camera, or EPIC, instrument captured 12 natural color images of the Moon’s shadow crossing over North America. EPIC is aboard NOAA’s Deep Space Climate Observatory, or DSCOVR, where it photographs the full sunlit side of Earth every day, giving it a unique view of the shadow from total solar eclipses. EPIC normally takes about 20 to 22 images of Earth per day, so this animation appears to speed up the progression of the eclipse.

A ground-based image of the total solar eclipse – which looks like a gray ring – is superimposed over a red-toned image of the Sun’s atmosphere, called the corona. This view of the corona was captured by the European Space Agency and our Solar and Heliospheric Observatory, or SOHO. At center is an orange-toned image of the Sun’s surface as seen by our Solar Dynamics Observatory in extreme ultraviolet wavelengths of light.

During a total solar eclipse, ground-based telescopes can observe the lowest part of the solar corona in a way that can’t be done at any other time, as the Sun’s dim corona is normally obscured by the Sun’s bright light. The structure in the ground-based corona image — defined by giant magnetic fields sweeping out from the Sun’s surface — can clearly be seen extending into the outer image from the space-based telescope. The more scientists understand about the lower corona, the more they can understand what causes the constant outward stream of material called the solar wind, as well as occasional giant eruptions called coronal mass ejections.

As millions of Americans watched the total solar eclipse that crossed the continental United States, the international Hinode solar observation satellite captured its own images of the awe-inspiring natural phenomenon. The images were taken with Hinode's X-ray telescope, or XRT, as it flew above the Pacific Ocean, off the west coast of the United States, at an altitude of approximately 422 miles. Hinode is a joint endeavor by the Japan Aerospace Exploration Agency, the National Astronomical Observatory of Japan, the European Space Agency, the United Kingdom Space Agency and NASA.

During the total solar eclipse our Lunar Reconnaissance Orbiter, or LRO, in orbit around the Moon, turned one of its instruments towards Earth to capture an image of the Moon’s shadow over a large region of the United States.

As LRO crossed the lunar south pole heading north at 3,579 mph, the shadow of the Moon was racing across the United States at 1,500 mph. A few minutes later, LRO began a slow 180-degree turn to look back at Earth, capturing an image of the eclipse very near the location where totality lasted the longest. The spacecraft’s Narrow Angle Camera began scanning Earth at 2:25:30 p.m. EDT and completed the image 18 seconds later.

Sensors on the polar-orbiting Terra and Suomi NPP satellites gathered data and imagery in swaths thousands of miles wide. The Moderate Resolution Imaging Spectroradiometer, or MODIS, sensor on Terra and Visible Infrared Imaging Radiometer Suite, or VIIRS, on Suomi NPP captured the data used to make this animation that alternates between two mosaics. Each mosaic is made with data from different overpasses that was collected at different times.

This full-disk geocolor image from NOAA/NASA’s GOES-16 shows the shadow of the Moon covering a large portion of the northwestern U.S. during the eclipse.

Our Interface Region Imaging Spectrograph, or IRIS, mission captured this view of the Moon passing in front of the Sun on Aug. 21.  

Check out nasa.gov/eclipse to learn more about the Aug. 21, 2017, eclipse along with future eclipses, and follow us on Twitter for more satellite images like these: @NASASun, @NASAMoon, and @NASAEarth.

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From the unique vantage point of about 25,000 feet above Earth, our Associate Administrator of Science at NASA, Dr. Thomas Zurbuchen, witnessed the 2017 eclipse. He posted this video to his social media accounts saying, “At the speed of darkness...watch as #SolarEclipse2017 shadow moves across our beautiful planet at <1 mile/second; as seen from GIII aircraft”. 

Zurbuchen, along with NASA Acting Administrator Robert Lightfoot, Associate Administrator Lesa Roe traveled on a specially modified Gulfstream III aircraft flying north over the skies of Oregon.

In order to capture images of the event, the standard windows of the Gulfstream III were replaced with optical glass providing a clear view of the eclipse. This special glass limits glare and distortion of common acrylic aircraft windows. Heaters are aimed at the windows where the imagery equipment will be used to prevent icing that could obscure a clear view of the eclipse.

Learn more about the observations of the eclipse made from this aircraft HERE.

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Eclipse Across America

August 21, 2017, the United States experienced a solar eclipse! 

An eclipse occurs when the Moon temporarily blocks the light from the Sun. Within the narrow, 60- to 70-mile-wide band stretching from Oregon to South Carolina called the path of totality, the Moon completely blocked out the Sun’s face; elsewhere in North America, the Moon covered only a part of the star, leaving a crescent-shaped Sun visible in the sky.

During this exciting event, we were collecting your images and reactions online. 

Here are a few images of this celestial event...take a look:

This composite image, made from 4 frames, shows the International Space Station, with a crew of six onboard, as it transits the Sun at roughly five miles per second during a partial solar eclipse from, Northern Cascades National Park in Washington. Onboard as part of Expedition 52 are: NASA astronauts Peggy Whitson, Jack Fischer, and Randy Bresnik; Russian cosmonauts Fyodor Yurchikhin and Sergey Ryazanskiy; and ESA (European Space Agency) astronaut Paolo Nespoli.

Credit: NASA/Bill Ingalls

The Bailey's Beads effect is seen as the moon makes its final move over the sun during the total solar eclipse on Monday, August 21, 2017 above Madras, Oregon.

Credit: NASA/Aubrey Gemignani

This image from one of our Twitter followers shows the eclipse through tree leaves as crescent shaped shadows from Seattle, WA.

Credit: Logan Johnson

“The eclipse in the palm of my hand”. The eclipse is seen here through an indirect method, known as a pinhole projector, by one of our followers on social media from Arlington, TX.

Credit: Mark Schnyder

Through the lens on a pair of solar filter glasses, a social media follower captures the partial eclipse from Norridgewock, ME.

Credit: Mikayla Chase

While most of us watched the eclipse from Earth, six humans had the opportunity to view the event from 250 miles above on the International Space Station. European Space Agency (ESA) astronaut Paolo Nespoli captured this image of the Moon’s shadow crossing America.

Credit: Paolo Nespoli

This composite image shows the progression of a partial solar eclipse over Ross Lake, in Northern Cascades National Park, Washington. The beautiful series of the partially eclipsed sun shows the full spectrum of the event. 

Credit: NASA/Bill Ingalls

In this video captured at 1,500 frames per second with a high-speed camera, the International Space Station, with a crew of six onboard, is seen in silhouette as it transits the sun at roughly five miles per second during a partial solar eclipse, Monday, Aug. 21, 2017 near Banner, Wyoming.

Credit: NASA/Joel Kowsky

To see more images from our NASA photographers, visit: https://www.flickr.com/photos/nasahqphoto/albums/72157685363271303

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Celebrate Today’s Solar Eclipse With NASA

Today, Aug. 21, the Moon’s shadow is sweeping across North America. People across the continent have the chance to see a partial solar eclipse if skies are clear.

For those within the narrow path of totality, stretching from Oregon to South Carolina, that partial eclipse will become total for a few brief moments. 

Make sure you’re using proper solar filters (not sunglasses) or an indirect viewing method if you plan to watch the eclipse in person.

Wherever you are, you can also watch today’s eclipse online with us at nasa.gov/eclipselive. Starting at noon ET, our show will feature views from our research aircraft, high-altitude balloons, satellites and specially-modified telescopes, as well as live reports from cities across the country and the International Space Station.

Learn all about today’s eclipse at eclipse2017.nasa.gov.

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You don't necessarily need fancy equipment to watch one of the sky's most awesome shows: a solar eclipse. With just a few simple supplies, you can make a pinhole camera that allows you to view the event safely and easily. Before you get started, remember: You should never look at the Sun directly without equipment that's specifically designed for solar viewing. Do not use standard binoculars or telescopes to watch the eclipse, as the light could severely damage your eyes. Sunglasses also do NOT count as protection when attempting to look directly at the Sun. Stay safe and still enjoy the Sun's stellar show by creating your very own pinhole camera. It's easy! 

See another pinhole camera tutorial at https://www.jpl.nasa.gov/edu/learn/project/how-to-make-a-pinhole-camera/

Watch this and other eclipse videos on our YouTube channel:  https://youtu.be/vWMf5rYDgpc?list=PL_8hVmWnP_O2oVpjXjd_5De4EalioxAUi

A pinhole camera is just one of many viewing options. Learn more at https://eclipse2017.nasa.gov/safety 

Music credit: Apple of My Eye by Frederik Wiedmann

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On Monday, August 21, 2017, our nation will be treated to a total eclipse of the Sun. The eclipse will be visible – weather permitting – across all of North America. The entire continent will experience at least a partial eclipse lasting two to three hours. Halfway through the event, anyone within a 60 to 70 mile-wide path from Oregon to South Carolina will experience a total eclipse. During those brief moments when the moon completely blocks the Sun's bright face for 2+ minutes, day will turn into night, making visible the otherwise hidden solar corona, the Sun's outer atmosphere. Bright stars and planets will become visible as well. This is truly one of nature's most awesome sights. The eclipse provides a unique opportunity to study the Sun, Earth, Moon and their interaction because of the eclipse's long path over land coast to coast.

Scientists will be able to take ground-based and airborne observations over a period of about 90 minutes to complement the wealth of data provided by NASA assets.

Watch this and other eclipse videos on our YouTube channel: https://youtu.be/8jaxiha8-rY?list=PL_8hVmWnP_O2oVpjXjd_5De4EalioxAUi

To learn all about the 2017 Total Eclipse: https://eclipse2017.nasa.gov/

Music credit: Ascending Lanterns by Philip Hochstrate

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How to Safely Watch the Aug. 21 Solar Eclipse

On Aug. 21, 2017, a solar eclipse will be visible in North America. Throughout the continent, the Moon will cover part – or all – of the Sun’s super-bright face for part of the day.

Since it’s never safe to look at the partially eclipsed or uneclipsed Sun, everyone who plans to watch the eclipse needs a plan to watch it safely. One of the easiest ways to watch an eclipse is solar viewing glasses – but there are a few things to check to make sure your glasses are safe:

 Glasses should have an ISO 12312-2 certification

They should also have the manufacturer’s name and address, and you can check if the manufacturer has been verified by the American Astronomical Society

Make sure they have no scratches or damage

To use solar viewing glasses, make sure you put them on before looking up at the Sun, and look away before you remove them. Proper solar viewing glasses are extremely dark, and the landscape around you will be totally black when you put them on – all you should see is the Sun (and maybe some types of extremely bright lights if you have them nearby).

Never use solar viewing glasses while looking through a telescope, binoculars, camera viewfinder, or any other optical device. The concentrated solar rays will damage the filter and enter your eyes, causing serious injury. But you can use solar viewing glasses on top of your regular eyeglasses, if you use them!

If you don’t have solar viewing glasses, there are still ways to watch, like making your own pinhole projector. You can make a handheld box projector with just a few simple supplies – or simply hold any object with a small hole (like a piece of cardstock with a pinhole, or even a colander) above a piece of paper on the ground to project tiny images of the Sun.

Of course, you can also watch the entire eclipse online with us. Tune into nasa.gov/eclipselive starting at noon ET on Aug. 21! 

For people in the path of totality, there will be a few brief moments when it is safe to look directly at the eclipse. Only once the Moon has completely covered the Sun and there is no light shining through is it safe to look at the eclipse. Make sure you put your eclipse glasses back on or return to indirect viewing before the first flash of sunlight appears around the Moon’s edge.

You can look up the length of the total eclipse in your area to help you set a time for the appropriate length of time. Remember – this only applies to people within the path of totality.

Everyone else will need to use eclipse glasses or indirect viewing throughout the entire eclipse!

Photographing the Eclipse

Whether you’re an amateur photographer or a selfie master, try out these tips for photographing the eclipse.  

#1 — Safety first: Make sure you have the required solar filter to protect your camera.

#2 — Any camera is a good camera, whether it’s a high-end DSLR or a camera phone – a good eye and vision for the image you want to create is most important.

#3 — Look up, down, and all around. As the Moon slips in front of the Sun, the landscape will be bathed in long shadows, creating eerie lighting across the landscape. Light filtering through the overlapping leaves of trees, which creates natural pinholes, will also project mini eclipse replicas on the ground. Everywhere you can point your camera can yield exceptional imagery, so be sure to compose some wide-angle photos that can capture your eclipse experience.

#4 — Practice: Be sure you know the capabilities of your camera before Eclipse Day. Most cameras, and even many camera phones, have adjustable exposures, which can help you darken or lighten your image during the tricky eclipse lighting. Make sure you know how to manually focus the camera for crisp shots.

#5 —Upload your eclipse images to NASA’s Eclipse Flickr Gallery and relive the eclipse through other peoples’ images.

Learn all about the Aug. 21 eclipse at eclipse2017.nasa.gov, and follow @NASASun on Twitter and NASA Sun Science on Facebook for more. Watch the eclipse through the eyes of NASA at nasa.gov/eclipselive starting at 12 PM ET on Aug. 21.

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Eclipse 2017: A Unique Chance for Science

On Aug. 21, the Moon will cast its shadow down on Earth, giving all of North America the chance to see a solar eclipse. Within the narrow, 60- to 70-mile-wide band stretching from Oregon to South Carolina called the path of totality, the Moon will completely block out the Sun’s face; elsewhere in North America, the Moon will cover only a part of the star, leaving a crescent-shaped Sun visible in the sky.

Find eclipse times for your location with our interactive version of this map.

A total solar eclipse happens somewhere on Earth about once every 18 months. But because Earth’s surface is mostly ocean, most eclipses are visible over land for only a short time, if at all. The Aug. 21 total solar eclipse is different – its path stretches over land for nearly 90 minutes, giving scientists an unprecedented opportunity to make scientific measurements from the ground.

No matter where you are, it is never safe to look directly at the partially eclipsed or uneclipsed Sun. Make sure you’re prepared to watch safely, whether that’s with solar viewing glasses, a homemade pinhole projector, or online with us at nasa.gov/eclipselive.

Within the path of totality, the Moon will completely obscure the Sun’s face for up to 2 minutes and 40 seconds, depending on location. This will give people within the path of totality a glimpse of the innermost reaches of the Sun’s corona, the outer region of the atmosphere that is thought to house the processes that kick-start much of the space weather that can influence Earth, as well as heating the whole corona to extraordinarily high temperatures.

In fact, scientists got their first hint at these unusually high temperatures during the total solar eclipse of 1869, when instruments detected unexpected light emission. It was later discovered that this emission happens when iron is stripped of its electrons at extremely high temperatures.

This region of the Sun’s atmosphere can’t be measured at any other time, as human-made instruments that create artificial eclipses must block out much of the Sun’s atmosphere – as well as its bright face – in order to produce clear images.

We’re funding six science investigations to study the Sun’s processes on Aug. 21. Teams will spread out across the path of totality, focusing their instruments on the Sun’s atmosphere. One team will use a pair of retro-fitted WB-57F jets to chase the Moon’s shadow across the eastern US, extending the time of totality to more than 7 minutes combined, up from the 2 minutes and 40 seconds possible on the ground.

Our scientists are also using the Aug. 21 eclipse as a natural science experiment to study how Earth’s atmosphere reacts to the sudden loss of solar radiation within the Moon’s shadow.

One region of interest is Earth’s ionosphere. Stretching from roughly 50 to 400 miles above Earth’s surface, the tenuous ionosphere is an electrified layer of the atmosphere that reacts to changes from both Earth below and space above and can interfere with communication and navigation signals.

The ionosphere is created by ionizing radiation from the Sun. When totality hits on Aug. 21, we’ll know exactly how much solar radiation is blocked, the area of land it’s blocked over and for how long. Combined with measurements of the ionosphere during the eclipse, we’ll have information on both the solar input and corresponding ionosphere response, enabling us to study the mechanisms underlying ionospheric changes better than ever before.

The eclipse is also a chance for us to study Earth’s energy system, which is in a constant dance to maintain a balance between incoming radiation from the Sun and outgoing radiation from Earth to space, called the energy budget. Like a giant cloud, the Moon during the 2017 total solar eclipse will cast a large shadow across a swath of the United States.

Our scientists already know the dimensions and light-blocking properties of the Moon, and will use ground and space instruments to learn how this large shadow affects the amount of sunlight reaching Earth’s surface, especially around the edges of the shadow. This will help develop new calculations that improve our estimates of the amount of solar energy reaching the ground, and our understanding of one of the key players in regulating Earth’s energy system — clouds.

Learn all about the Aug. 21 eclipse at eclipse2017.nasa.gov, and follow @NASASun on Twitter and NASA Sun Science on Facebook for more. Watch the eclipse through the eyes of NASA at nasa.gov/eclipselive starting at 12 PM ET on Aug. 21.

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The total solar eclipse is coming! Here’s your chance to ask an eclipse scientist your questions! Have questions about the upcoming total solar eclipse on August 21? Join our Tumblr Answer Time session on Thursday, August 17 from 3:00 – 4:00 p.m. EDT/12:00 - 1:00 p.m. PDT. here on NASA’s Tumblr, where space physics researcher Alexa Halford will answer them. Make sure to ask your questions now by visiting: https://nasa.tumblr.com/ask!

See all the #AnswerTime questions here: https://nasa.tumblr.com/tagged/answertime

Alexa Halford is a space physics researcher at our Goddard Space Flight Center and Dartmouth College. She started researching waves in Earth's magnetosphere as an undergraduate at Augsburg College with Mark Engebretson using ground based magnetometers in the Arctic and Antarctic. She moved away from waves to focus on geomagnetic storms and substorms during her masters at the University of Colorado Boulder with Dan Baker but returned once more to waves with her PhD at University of Newcastle NSW Australia. Her PhD thesis was on Electromagnetic Ion Cyclotron (EMIC) waves during the CRRES mission and their relationship to the plasmasphere and radiation belts.

She is member of the scientific team for a NASA-funded scientific balloon experiment project called BARREL (Balloon Array for RBSP Relativistic Electron Losses) where she looks at the population of particles lost due to these interactions. She is now currently a contractor at NASA Goddard continuing work the BARREL and NASA Van Allen Probes satellite missions.

To get more information about the eclipse, visit: https://eclipse2017.nasa.gov/

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