Sun - Blog Posts
House of Horrors: Exoplanet Edition
Astronomers may be closer than ever to discovering a planet that’s habitable like our own, but along the way they’ve discovered some very scary exoplanets – places where conditions are far too harsh for life as we know it to exist.
Okay, but what IS an exoplanet???
We’ve rounded up some of the most frightening, deadly exoplanets, places that make even the scariest haunted house on Earth pale in comparison. Check them out...
Radiation Bath, Anyone?
The exoplanets PSR B1257+12 B, C & D were among the first discovered, and also happened to be three of the weirdest! The entire system is a graveyard, remnants of what used to be a normal, functional solar system before the star blew apart in a giant explosion known as a supernova.
The massive shockwave from the supernova stripped away any atmosphere or living creatures that might have once lived on these planets, leaving behind ghostly, rocky shells, dead planets orbiting the corpse of an extinct star.
Except that the system isn’t completely dead…the remaining core from the old star has become a zombie star called a pulsar. Literally spinning in its grave, it makes a full rotation every 6.22 milliseconds and emits an intense beam of radiation that can be detected from Earth. The star’s unfortunate planets are thus bathed in deadly radiation on a regular basis, making sure that this system remains a cosmic no-man’s land.
A Mighty Wind
The sound of howling wind is a must for any Earth-based haunted house, but weather conditions on HD 189733 b make it a very dangerous place to go trick-or-treating.
At first glance, this exoplanet looks like the typical “hot Jupiter” — a huge gas planet perched dangerously to a burning-hot star, with daytime temperatures around a balmy 1,770 degrees Fahrenheit. This exoplanet is also “tidally locked” in its orbit, which means that the same side of the planet always faces its star.
But when scientists measured the planet’s nighttime temperature, they were shocked to find that it was only 500 degrees cooler. How does the back side of the planet stay so warm?
The answer is wind! Insanely fast, dangerous wind that whisks heat from day-side to night-side at a speed of 4,500 mph, nearly six times the speed of sound! In fact, astronomers estimate that wind speeds might top out at 5,400 mph, conditions that make hurricanes on Earth look like a breezy day at the beach.
Newborn Exoplanet Around Scorching Star
This exoplanet, named K2-33b, is the youngest fully formed exoplanet ever detected. This planet is a bit larger than Neptune and whips tightly around its star every five days. Since this planet sits nearly 10 times closer to its star than Mercury is to our sun, it’s HOT!
No matter how cute you think infants are, this is one baby you’d want to stay away from.
Boil, Boil, Toil and Trouble
The planet HD 209458 b (aka. Osiris - the god of death) has a few things in common with Earth: water vapor, methane and carbon dioxide in its atmosphere, key ingredients for life on our planet. Don’t be fooled, though, because this planet is a rolling cauldron of almost unimaginable heat.
Even the hottest summer days on Earth don’t get as dangerous as the conditions here. A planet that orbits so close to its host star that its atmosphere is literally boiling off, ripped away from the planet as it whips around on its breakneck 3.5-day orbit.
All Alone and Very, Very Cold
While most of the exoplanets found so far are hellishly hot, OGLE-2005-BLG-390L b has the distinction of being extremely cold.
The planet takes about 10 Earth years to orbit its tiny dwarf star, and it’s a chilly trip; the average temperature on this exoplanet is 50 Kelvin, or minus 370 degrees Fahrenheit! A good costume for trick-or-treating on this frigid planet would be a toasty self-heating spacesuit, an oxygen supply, ice skates and plenty of hot cocoa.
Of course, don’t expect to find many houses with candy here, because despite the fact that it’s just a few times bigger than Earth, this exoplanet is an uninhabitable ice ball stuck in a perpetual winter freeze.
A Scorched World
Kepler-10b is a scorched world, orbiting at a distance that’s more than 20 times closer to its star than Mercury is to our own sun. The daytime temperatures are expected to be more than 2,500 degrees Fahrenheit, hotter than lava flows here on Earth.
Intense radiation from the star has kept the planet from holding onto an atmosphere, but flecks of silicates and iron that have boiled off a molten surface are swept away by the stellar radiation.
Learn more about worlds beyond our solar system at: https://exoplanets.nasa.gov/
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Celebrating 10 Years of Revolutionary Solar Views
Twin spacecraft give humanity unprecedented views of the entire sun at one time, traveling to the far side of our home star over the course of a 10-year mission.
These two spacecraft are called STEREO, short for Solar and Terrestrial Relations Observatory. Launched on Oct. 25, 2006, and originally slated for a two-year mission, both spacecraft sent back data for nearly eight years, and STEREO-A still sends information and images from its point of view on the far side of the sun.
STEREO watches the sun from two completely new perspectives. It also provides information invaluable for understanding the sun and its impact on Earth, other worlds, and space itself – collectively known as space weather. On Earth, space weather can trigger things like the aurora and, in extreme cases, put a strain on power systems or damage high-flying satellites.
Because the rest of our sun-watching satellites orbit near our home planet, STEREO’s twin perspectives far from Earth give us a unique opportunity to look at solar events from all sides and understand them in three dimensions.
We use data from STEREO and other missions to understand the space environment throughout the solar system. This helps operators for missions in deep space prepare for the sudden bursts of particles and magnetic field that could pose a danger to their spacecraft.
STEREO has also helped us understand other objects in our solar system – like comets. Watching how a comet’s tail moves gives us clues about the constant stream of particles that flows out from the sun, called the solar wind.
STEREO is an essential piece of our heliophysics fleet, which includes 17 other missions. Together, these spacecraft shed new light on the sun and its interaction with space, Earth, and other worlds throughout the solar system.
To celebrate, we’re hosting a Facebook Live event on Wednesday, Oct. 26. Join us at noon ET on the NASA Sun Science Facebook page to learn more about STEREO and ask questions.
Learn more about how NASA studies the sun at: www.nasa.gov/stereo
Follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
A Space Odyssey: 21 Years of Searching for Another Earth
There are infinite worlds both like and unlike this world of ours. We must believe that in all worlds there are living creatures and plants and other things we see in this world. – Epicurus, c. 300 B.C.
Are we alone? Are there other planets like ours? Does life exist elsewhere in the universe?
These are questions mankind has been asking for years—since the time of Greek philosophers. But for years, those answers have been elusive, if not impossible to find.
The month of October marks the 21st anniversary of the discovery of the first planet orbiting another sun-like star (aka. an exoplanet), 51 Pegasi b or “Dimidium.” Its existence proved that there were other planets in the galaxy outside our solar system.*
Even more exciting is the fact that astronomers are in hot pursuit of the first discovery of an Earth-like exoplanet orbiting a star other than the sun. The discovery of the so-called "blue dot" could redefine our understanding of the universe and our place in it, especially if astronomers can also find signs that life exists on that planet's surface.
Astronomy is entering a fascinating era where we're beginning to answer tantalizing questions that people have pondered for thousands of years.
Are we alone?
In 1584, when the Catholic monk Giordano Bruno asserted that there were "countless suns and countless earths all rotating around their suns," he was accused of heresy.
But even in Bruno's time, the idea of a plurality of worlds wasn't entirely new. As far back as ancient Greece, humankind has speculated that other solar systems might exist and that some would harbor other forms of life.
Still, centuries passed without convincing proof of planets around even the nearest stars.
Are there other planets like ours?
The first discovery of a planet orbiting a star similar to the sun came in 1995. The Swiss team of Michel Mayor and Didier Queloz of Geneva announced that they had found a rapidly orbiting gas world located blisteringly close to the star 51 Pegasi.
This announcement marked the beginning of a flood of discoveries. Exotic discoveries transformed science fiction into science fact:
a pink planet
worlds with two or even three suns
a gas giant as light as Styrofoam
a world in the shape of an egg
a lava planet
But what about another Earth?
Our first exoplanet mission**, Kepler, launched in 2009 and revolutionized how astronomers understand the universe and our place in it. Kepler was built to answer the question—how many habitable planets exist in our galaxy?
And it delivered: Thousands of planet discoveries poured in, providing statistical proof that one in five sun-like stars (yellow, main-sequence G type) harbor Earth-sized planets orbiting in their habitable zones– where it’s possible liquid water could exist on their surface.
Now, our other missions like the Hubble and Spitzer space telescopes point at promising planetary systems (TRAPPIST-1) to figure out whether they are suitable for life as we know it.
Does life exist elsewhere in the universe?
Now that exoplanet-hunting is a mainstream part of astronomy, the race is on to build instruments that can find more and more planets, especially worlds that could be like our own.
Our Transiting Exoplanet Survey Satellite (TESS), set for launch in 2017-2018, will look for super-Earth and Earth-sized planets around stars much closer to home. TESS will find new planets the same way Kepler does—via the transit method—but will cover 400 times the sky area.
The James Webb Space Telescope, to launch in 2018, wil be our most powerful space telescope to date. Webb will use its spectrograph to look at exoplanet atmospheres, searching for signs of life.
We still don’t know where or which planets are in the habitable zones of the nearest stars to Earth. Searching out our nearest potentially habitable neighbors will be the next chapter in this unfolding story.
*The first true discovery of extrasolar planets was actually a triplet of dead worlds orbiting the remains of an exploded star, called a pulsar star. Two of three were found by Dr. Alexander Wolszczan in 1992– a full three years before Dimidium’s discovery. But because they are so strange, and can’t support life as we know it, most scientists would reserve the “first” designation for a planet orbiting a normal star.
** The French CoRoT mission, launched in 2006, was the first dedicated exoplanet space mission. It has contributed dozens of confirmed exoplanets to the ranks and boasts a roster of some of the most well-studied planets outside our solar system.
To stay up-to-date on our latest exoplanet discoveries, visit: https://exoplanets.nasa.gov
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
It’s Friday...Come Space Out with Us
It’s Friday…which seems like a great excuse to take a look at some awesome images from space.
First, let’s start with our home planet: Earth.
This view of the entire sunlit side of Earth was taken from one million miles away…yes, one MILLION! Our EPIC camera on the Deep Space Climate Observatory captured this image in July 2015 and the picture was generated by combining three separate images to create a photographic-quality image.
Next, let’s venture out 4,000 light-years from Earth.
This image, taken by the Hubble Space Telescope, is not only stunning…but shows the colorful “last hurrah” of a star like our sun. This star is ending its life by casting off its outer layers of gas, which formed a cocoon around the star’s remaining core. Our sun will eventually burn out and shroud itself with stellar debris…but not for another 5 billion years.
The material expelled by the star glows with different colors depending on its composition, its density and how close it is to the hot central star. Blue samples helium; blue-green oxygen, and red nitrogen and hydrogen.
Want to see some rocks on Mars?
Here’s an image of the layered geologic past of Mars revealed in stunning detail. This color image was returned by our Curiosity Mars rover, which is currently “roving” around the Red Planet, exploring the “Murray Buttes” region.
In this region, Curiosity is investigating how and when the habitable ancient conditions known from the mission’s earlier findings evolved into conditions drier and less favorable for life.
Did you know there are people currently living and working in space?
Right now, three people from three different countries are living and working 250 miles above Earth on the International Space Station. While there, they are performing important experiments that will help us back here on Earth, and with future exploration to deep space.
This image, taken by NASA astronaut Kate Rubins shows the stunning moonrise over Earth from the perspective of the space station.
Lastly, let’s venture over to someplace REALLY hot…our sun.
The sun is the center of our solar system, and makes up 99.8% of the mass of the entire solar system…so it’s pretty huge. Since the sun is a star, it does not have a solid surface, but is a ball of gas held together by its own gravity. The temperature at the sun’s core is about 27 million degrees Fahrenheit (15 million degrees Celsius)…so HOT!
This awesome visualization appears to show the sun spinning, as if stuck on a pinwheel. It is actually the spacecraft, SDO, that did the spinning though. Engineers instructed our Solar Dynamics Observatory (SDO) to roll 360 degrees on one axis, during this seven-hour maneuver, the spacecraft took an image every 12 seconds.
This maneuver happens twice a year to help SDO’s imager instrument to take precise measurements of the solar limb (the outer edge of the sun as seen by SDO).
Thanks for spacing out with us...you may now resume your Friday.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Mercury In the Spotlight
For more than seven hours on Monday, May 9, Mercury will be visible as a tiny black dot crossing the face of the sun. This rare event – which happens only slightly more than once a decade – is called a transit.
Although Mercury whips around the sun every 88 days – over four times faster than Earth – the three bodies rarely align. Because Mercury orbits in a plane 7 degrees tilted from Earth’s orbit, it usually darts above or below our line of sight to the sun. As a result, a Mercury transit happens only about 13 times a century. The last one was in 2006, and the next one isn’t until 2019.
When: On May 9, shortly after 7:00 a.m. EDT, Mercury will appear as a tiny black dot against a blazing backdrop, traversing the sun’s disk over seven and a half hours. Mercury will cross the edge of the sun (ingress) after 7:00 a.m. EDT. The mid-transit point will occur a little after 10:45 a.m. EDT, with egress around 2:30 p.m. EDT.
Where: Skywatchers in Western Europe, South America and eastern North America will be able to see the entirety of the transit. The entire 7.5-hour path across the sun will be visible across the Eastern U.S. – with magnification and proper solar filters – while those in the West can observe the transit in progress at sunrise.
Safety!
Unlike the 2012 Venus transit of the sun, Mercury is too small to be visible without magnification from a telescope or high-powered binoculars. Both must have safe solar filters made of specially-coated glass or Mylar; you can never look directly at the sun. We’re offering several avenues for the public to view the event without specialized and costly equipment, including images on NASA.gov, a one-hour NASA Television special, and social media coverage.
The Science…Why are Planetary Transits Important?
Transits like this allowed scientists in the 17th century to make the first estimates of Earth’s distance from the sun. Transit observations over the past few centuries have also helped scientists study everything from the atmosphere of Venus to the slight shifts in Mercury’s orbit that could only be explained by the theory of general relativity. Because we know Mercury’s size and location precisely, this transit will help scientists calibrate telescopes on solar observatories SDO, SOHO, and Hinode.
Transits can also teach us more about planets – both in and out of our solar system. The Venus transit in 2012 provided observations of the planet's atmosphere. Transits are also the main way we find planets outside the solar system, called exoplanets.
The transit method looks for a drop in the brightness of a star when a planet passes in front of it. This method will not find every planet – only those that happen to cross our line of sight from Earth to the star. But with enough sensitivity, the transit method through continuous monitoring is a great way to detect small, Earth-size planets, and has the advantage of giving us both the planet’s size (from the fraction of starlight blocked), as well as its orbit (from the period between transits). Our Kepler/K2 mission uses this method to find exoplanets, as will the Transiting Exoplanet Survey Satellites, or TESS, following its launch in 2017/2018.
We will stream a live program on NASA TV and the agency’s Facebook page from 10:30 to 11:30 a.m. -- an informal roundtable during which experts representing planetary, heliophysics and astrophysics will discuss the science behind the Mercury transit. Viewers can ask questions via Facebook and Twitter using #AskNASA.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Worlds That Will Make You Believe Star Wars is Real
The fantastical planets in Star Wars preceded our discovery of real planets outside our solar system…but fiction isn’t too far from the facts. When we send our spacecraft into the solar system and point our telescopes beyond, we often see things that seem taken right out of the Star Wars universe.
Is there a more perfect time than May the 4th to compare real worlds to the ones depicted in Star Wars?
Probably not...so here are a few:
Mimas
Saturn’s moon, Mimas, has become known as the "Death Star" moon because of how its 80-mile wide Herschel crater creates a resemblance to the Imperial battle station, especially when seen in this view from our Cassini spacecraft.
Kepler-452b
The most recently revealed exoplanet dubbed as Earth’s bigger, older cousin, Kepler-452b, might make a good stand-in for Coruscant — the high tech world seen in several Star Wars films whose surface is encased in a single, globe-spanning city. Kepler-452b belongs to a star system 1.5 billion years older than Earth’s! That would give any technologically adept species more than a billion-year jump ahead of us.
CoRoT-7b
At 3,600 degrees Fahrenheit, CoRoT-7B is a HOT planet. Discovered in 2010 with France’s CoRoT satellite, it’s some 480 light-years away, and has a diameter 70% larger than Earth’s, with nearly five times the mass. Possibly the boiled-down remnant of a Saturn-sized planet, its orbit is so tight that its star looms much larger in its sky than our sun appears to us, keeping its sun-facing surface molten! This scorching planet orbiting close to its star could be a good analog for planet Mustafar from Star Wars.
Kepler-16b
Luke Skywalker’s home planet, Tatooine, is said to possess a harsh, desert environment, swept by sandstorms as it roasts under the glare of twin suns. Real exoplanets in the thrall of two or more suns are even harsher! Kepler-16b was the Kepler telescope’s first discovery of a planet in a “circumbinary” orbit (a.k.a, circling both stars, as opposed to just one, in a double star system). This planet, however, is likely cold, about the size of Saturn, and gaseous, though partly composed of rock.
OGLE-2005-BLG-390
Fictional Hoth is a frozen tundra that briefly serves as a base for the hidden Rebel Alliance. It’s also the nickname of real exoplanet OGLE-2005-BLG-390, a cold super-Earth whose surface temperature clocks in at minus 364 degrees Fahrenheit.
Kepler-22b
Kepler-22b, analog to the Star Wars planet Kamino…which was the birthplace of the army of clone soldiers, is a super-Earth that could be covered in a super ocean. The jury is still out on Kepler-22b’s true nature; at 2.4 times Earth’s radius, it might even be gaseous. But if the ocean world idea turns out to be right, we can envision a physically plausible Kamino-like planet.
Gas Giants
Gas giants of all stripes populate the real exoplanet universe; in Star Wars, a gas giant called Bespin is home to a “Cloud City” actively involved in atmospheric mining. Mining the atmospheres of giant gas planets is a staple of science fiction. We too have examined the question, and found that gases such as helium-3 and hydrogen could theoretically be extracted from the atmospheres of Uranus and Neptune.
Exomoons
Endor, the forested realm of the Ewoks, orbits a gas giant. Exomoon detection is still in its infancy for scientists on Earth. However, a possible exomoon (a moon circling a distant planet) was observed in 2014 via microlensing. It will remain unconfirmed, however, since each microlensing event can be seen only once.
May the 4th be with you!
Discover more about exoplanets here: https://exoplanets.jpl.nasa.gov/
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Solar System: Things to Know This Week
The solar system is vast, and exploring it requires not one expedition, but many. From the sun to the Earth to the depths of space beyond Pluto, an entire fleet of spacecraft is pushing back the frontiers of knowledge. Scientists and engineers around the world work together on dozens of missions, and the results of their work unfold on a daily basis. During any given week, astronauts and robotic spacecraft return thousands of pictures and other data from Earth orbit and from half a dozen other worlds.
The result? It’s nothing short of a visual and intellectual feast. For example, all of the following images were obtained over the course of one week during January this year.
The same missions that took these pictures are still at work – they may be photographing Saturn or transmitting a report from Mars as you read this.
1. The Sun
From its clear vantage point in Earth orbit, our Solar Dynamics Observatory (SDO) observes our nearby star almost continuously. This image shows activity on the sun’s surface on Jan. 18. You can also get similar pictures from SDO daily!
2. The Earth from Afar
The DSCOVR satellite orbits the Earth at a distance of nearly a million miles (1.5 million kilometers). It’s Earth Polychromatic Imaging Camera (EPIC) keeps a steady watch on the home planet. This is how the world turned on Jan. 20. Get the latest daily images from EPIC HERE.
3. Mars from Above
The team that manages the Mars Reconnaissance Orbiter (MRO) recently celebrated a decade of observing the Red Planet. MRO took this detailed look at dunes and rocky buttes in Danielson Crater on Jan. 24. It was 3:06 p.m., local Mars time. On the right stide of the image, dust devils have left tracks in the sand.
4. Comet 67/P
The European Space Agency’s Rosetta probe caught this look at the surface of Comet 67/P from a distance of just 46 miles (75 kilometers) on Jan. 23.
5. Saturn
On the same day (Jan. 23), our Cassini spacecraft continued its odyssey of nearly two decades in space, bringing us this look at the sixth planet. See the latest images from Cassini HERE.
Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Fun Facts About Mars
Mars is a cold desert world, and is the fourth planet from the sun. It is half the diameter of Earth and has the same amount of dry land. Like Earth, Mars has seasons, polar ice caps, volcanoes, canyons and weather, but its atmosphere is too thin for liquid water to exist for long on the surface. There are signs of ancient floods on the Red Planet, but evidence for water now exists mainly in icy soil and thin clouds.
Earth has one, Mars has two…moons of course! Phobos (fear) and Deimos (panic) are the Red Planet’s two small moons. They are named after the horses that pulled the chariot of the Greek war god Ares, the counterpart to the Roman war god Mars.
The diameter of Mars is 4220 miles (6792 km). That means that the Red Planet is twice as big as the moon, but the Earth is twice as big as Mars.
Since Mars has less gravity than Earth, you would weigh 62% less than you do here on our home planet. Weigh yourself here on the Planets App. What’s the heaviest thing you’ve ever lifted? On Mars, you could have lifted more than twice that! Every 10 pounds on Earth only equals 4 pounds on the Red Planet. Find out why HERE.
Mass is the measurement of the amount of matter something contains. Mars is about 1/10th of the mass of Earth.
Mars and Earth are at their closest point to each other about every two years, with a distance of about 33 million miles between them at that time. The farthest that the Earth and Mars can be apart is: 249 million miles. This is due to the fact that both Mars and Earth have elliptical orbits and Mars’ orbit is tilted in comparison with the Earth’s. They also orbit the sun at different rates.
The temperature on Mars can be as high as 70 degrees Fahrenheit (20 degrees Celsius) or as low as about –225 degrees Fahrenheit (-153 degrees Celsius). How hot or cold the surface varies between day and night and among seasons. Mars is colder than Earth because it is farther from the sun.
You know that onions have layers, but did you know that Mars has layers too? Like Earth, Mars has a crust, a mantle and a core. The same stuff even makes up the planet layers: iron and silicate.
Ever wonder why it’s so hard launching things to space? It’s because the Earth has a log of gravity! Gravity makes things have weight, and the greater the gravity, the more it weights. On Mars, things weigh less because the gravity isn’t as strong.
Take a deep breath. What do you think you just breathed in? Mostly Nitrogen, about a fifth of that breath was Oxygen and the rest was a mix of other gases. To get the same amount of oxygen from one Earth breath, you’d have to take around 14,500 breaths on Mars! With the atmosphere being 100 times less dense, and being mostly carbon dioxide, there’s not a whole lot of oxygen to breathe in.
Mars has about 15% of Earth’s volume. To fill Earth’s volume, it would take over 6 Mars’ volumes.
For more fun Mars facts, visit HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Leap Day…Why Does It Exist?
Once every four years, an extra calendar day is added: a leap day. But why?
The reason for adding leap days to the calendar is to align the calendar year with the actual year – which is defined by the time it takes Earth to circle the sun. It is equal to 365 days, 5 hours, 48 minutes and 46 seconds, or 365.24219 days.
If all calendar years contained exactly 365 days, they would drift from the actual year by about 1 day every 4 years. Eventually, July would occur during the northern hemisphere winter! Wouldn’t that be weird?
To correct (approximately), we add 1 day every 4 years...resulting in a leap year.
By making most years 365 days but every fourth year 366 days, the calendar year and the actual year remain more nearly in step.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
20 Years of the Solar and Heliospheric Observatory
The Solar and Heliospheric Observatory, SOHO for short, has captured the imagination of scientists and the public alike for two decades now. We teamed up with the European Space Agency (ESA) on SOHO, which observes the sun from space. It was launched 20 years ago this week, on Dec. 2, 1995, with the mission to study the internal structure of our neighborhood star, its atmosphere and the origin of the solar wind. SOHO sends spectacular data daily, and has led scientists to a wealth of understanding.
Here are the top 5 things you need to know about SOHO, the sun and other solar observation missions:
1. SOHO Set Out for Space with an Ambitious Mission
SOHO was designed to answer three fundamental scientific questions about the sun: What are the structure and dynamics of the solar interior? Why does the solar corona exist and how is it heated to such an extremely high temperature? Where is the solar wind produced and how is it accelerated? Clues about the solar interior come from studying seismic waves that appear as ripples on the sun's surface, a technique called helioseismology.
2. SOHO Enjoys a Great View
SOHO commands an uninterrupted view of the sun, while always staying within easy communication range of controllers at home. The space-based observatory moves around the sun in step with the Earth, by slowly orbiting around a unique point in space called the First Lagrangian Point (L1). There, the combined gravity of the Earth and sun keep SOHO in a position that's always between the sun and the Earth. The L1 point is about 1 million miles (about 1.5 million kilometers) away from Earth (about four times the distance to the Moon).
3. Bonus Discoveries: Lots of Comets
Besides watching the sun, SOHO has become the most prolific discoverer of comets in astronomical history. In September 2015, SOHO found its 3000th comet. Sometimes the spacecraft's instruments capture comets plunging to their death as they collide with the sun.
4. Extra Innings
SOHO was meant to operate until 1998, but it was so successful that ESA and NASA decided to prolong its life several times and endorsed several mission extensions. Because of this, the mission has been able to observe an entire 11-year solar cycle and much of the next.
5. Keep Your Eye (Safely) on the Sun
You can see what SOHO sees, almost in real time. The latest images from the spacecraft, updated several times daily, are available online. Take a look HERE.
Also, make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Solar System: 5 Things To Know This Week
Our solar system is huge, so let us break it down for you. Here are 5 things to know this week:
1. Dancing with a Star
Our local star, better known as the sun, teems with activity. This month NASA has been tracking regions that burst with magnetic loops. The Solar Dynamics Observatory is one of several space-based assets that keep tabs on the sun daily, watching as charged particles trace the magnetic field, forming bright lines as they emit light in ultraviolet wavelengths.
2. An Idyll for Ida
On Nov. 24, the asteroid Ida makes its closest approach to Earth (at a very safe distance). Ida is the first asteroid found to have its own moon, and the second ever visited by a spacecraft. Its close encounter happened in 1993 as Galileo flew by en route to Jupiter.
3. Moonshine
On Nov. 23, the Cassini spacecraft will fly near Saturn's icy moon Tethys. Several instruments aboard Cassini will collect data, including an eight-frame color image mosaic. Between Nov. 27 and Dec. 2, Cassini will have very limited communications with Earth, because Cassini will enter solar conjunction, when Cassini and Saturn are on the other side of the Sun from Earth.
4. The Moon Will Occult Aldebaran
That may sound ominous, but all it means is that Earth's moon will pass in front of the giant red star Aldebaran on Nov. 26. Aldebaran is the bright "eye" of the constellation Taurus. The event will only be visible in some parts of North America. Details can be found HERE.
5. One Wild Ride, One Year Later
What a year it's been for the Rosetta mission since the Philae lander came to rest on the surface of Comet 67P/Churyumov-Gerasimenko in November 2014. A steady flow of data from the orbiter, together with several days of information sent from the lander, is providing a detailed picture of this remnant from the creation of the solar system.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Things You Might Not Know About Our Sun
The sun is a star, a hot ball of glowing gases at the heart of our solar system. Its influence extends far beyond the orbits of distant Neptune and Pluto. Without the sun’s intense energy and heat, there would be no life on Earth. And though it is special to us, there are billions of stars like our sun scattered across the Milky Way galaxy.
Impress Your Friends with These Sun Facts:
If the sun were as tall as a typical front door, the Earth would be the size of a U.S. nickel
The temperature at the sun’s core is about 27 million degrees Fahrenheit
Our sun is more massive than the average star in its neighborhood. Nearly 90% of stars are less massive, making them cooler and dimmer
The sun contains 99.9% of all matter in our solar system
During a single second, the sun converts 4 million tons of matter to pure energy
It would take about 1 million Earths to fill the sun if it were a hollow ball
The sun rotates on its axis approximately once every 27 days
The sun is 93 million miles away from Earth and is almost 5 billion years old
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
10 Intriguing Worlds Beyond Our Solar System
In celebration of the 20th anniversary of the first confirmed planet around a sun-like star, a collection of some interesting exoplanets has been put together. Some of these are rocky, some are gaseous and some are very, very cold. But there’s one thing each these strange new worlds have in common: All have advanced scientific understanding of our place in the cosmos. Check out these 10 exoplanets, along with artist’s concepts depicting what they might look like. For an extended list of 20 exoplanets, go HERE.
1. Kepler-186f
Kepler-186f was the first rocky planet to be found within the habitable zone -- the region around the host star where the temperature is right for liquid water. This planet is also very close in size to Earth. Even though we may not find out what’s going on at the surface of this planet anytime soon, it’s a strong reminder of why new technologies are being developed that will enable scientists to get a closer look at distance worlds.
More Info
2. HD 209458 b (nickname “Osiris”)
The first planet to be seen in transit (crossing its star) and the first planet to have it light directly detected. The HD 209458 b transit discovery showed that transit observations were feasible and opened up an entire new realm of exoplanet characterization.
More info
3. Kepler-11 system
This was the first compact solar system discovered by Kepler, and it revealed that a system can be tightly packed, with at least five planets within the orbit of Mercury, and still be stable. It touched off a whole new look into planet formation ideas and suggested that multiple small planet systems, like ours, may be common.
More info
4. Kepler-16b
A real-life "Tatooine," this planet was Kepler's first discovery of a planet that orbits two stars -- what is known as a circumbinary planet.
More info
5. 51 Pegasi b
This giant planet, which is about half the mass of Jupiter and orbits its star every four days, was the first confirmed exoplanet around a sun-like star, a discovery that launched a whole new field of exploration.
More info
6. CoRoT 7b
The first super-Earth identified as a rocky exoplanet, this planet proved that worlds like the Earth were indeed possible and that the search for potentially habitable worlds (rocky planets in the habitable zone) might be fruitful.
More info
7. Kepler-22b
A planet in the habitable zone and a possible water-world planet unlike any seen in our solar system.
More info
8. Kepler-10b
Kepler's first rocky planet discovery is a scorched, Earth-size world that scientists believe may have a lava ocean on its surface.
More info
9. Kepler-444 system
The oldest known planetary system has five terrestrial-sized planets, all in orbital resonance. This weird group showed that solar systems have formed and lived in our galaxy for nearly its entire existence.
More info
10. 55 Cancri e
Sauna anyone? 55 Cancri e is a toasty world that rushes around its star every 18 hours. It orbits so closely -- about 25 times closer than Mercury is to our sun -- that it is tidally locked with one face forever blistering under the heat of its sun. The planet is proposed to have a rocky core surrounded by a layer of water in a “supercritical” state, where it is both liquid and gas, and then the whole planet is thought to be topped by a blanket of steam.
More info
NASA’s Fleet of Planet-hunters and World-explorers
Around every star there could be at least one planet, so we’re bound to find one that is rocky, like Earth, and possibly suitable for life. While we’re not quite to the point where we can zoom up and take clear snapshots of the thousands of distant worlds we’ve found outside our solar system, there are ways we can figure out what exoplanets light years away are made of, and if they have signs of basic building blocks for life. Here are a few current and upcoming missions helping us explore new worlds:
Kepler
Launched in 2009, the Kepler space telescope searched for planets by looking for telltale dips in a star’s brightness caused by crossing, or transiting, planets. It has confirmed more than 1,000 planets; of these, fewer than 20 are Earth-size (therefore possibly rocky) and in the habitable zone -- the area around a star where liquid water could pool on the surface of an orbiting planet. Astronomers using Kepler data found the first Earth-sized planet orbiting in the habitable zone of its star and one in the habitable zone of a sun-like star.
In May 2013, a second pointing wheel on the spacecraft broke, making it not stable enough to continue its original mission. But clever engineers and scientists got to work, and in May 2014, Kepler took on a new job as the K2 mission. K2 continues the search for other worlds but has introduced new opportunities to observe star clusters, young and old stars, active galaxies and supernovae.
Transiting Exoplanet Survey Satellite (TESS)
Revving up for launch around 2017-2018, NASA’s Transiting Exoplanet Survey Satellite (TESS) will find new planets the same way Kepler does, but right in the stellar backyard of our solar system while covering 400 times the sky area. It plans to monitor 200,000 bright, nearby stars for planets, with a focus on finding Earth and Super-Earth-sized planets.
Once we’ve narrowed down the best targets for follow-up, astronomers can figure out what these planets are made of, and what’s in the atmosphere. One of the ways to look into the atmosphere is through spectroscopy.
As a planet passes between us and its star, a small amount of starlight is absorbed by the gas in the planet’s atmosphere. This leaves telltale chemical “fingerprints” in the star’s light that astronomers can use to discover the chemical composition of the atmosphere, such as methane, carbon dioxide, or water vapor.
James Webb Space Telescope
Launching in 2018, NASA’s most powerful telescope to date, the James Webb Space Telescope (JWST), will not only be able to search for planets orbiting distant stars, its near-infrared multi-object spectrograph will split infrared light into its different colors- spectrum- providing scientists with information about an physical properties about an exoplanet’s atmosphere, including temperature, mass, and chemical composition.
Hubble Space Telescope
Hubble Space Telescope is better than ever after 25 years of science, and has found evidence for atmospheres bleeding off exoplanets very close to their stars, and even provided thermal maps of exoplanet atmospheres. Hubble holds the record for finding the farthest exoplanets discovered to date, located 26,000 light-years away in the hub of our Milky Way galaxy.
Chandra X-ray Observatory
Chandra X-ray Observatory can detect exoplanets passing in front of their parent stars. X-ray observations can also help give clues on an exoplanet’s atmosphere and magnetic fields. It has observed an exoplanet that made its star act much older than it actually is.
Spitzer Space Telescope
Spitzer Space Telescope has been unveiling hidden cosmic objects with its dust-piercing infrared vision for more than 12 years. It helped pioneer the study of atmospheres and weather on large, gaseous exoplanets. Spitzer can help narrow down the sizes of exoplanets, and recently confirmed the closest known rocky planet to Earth.
SOFIA
The Stratospheric Observatory for Infrared Astronomy (SOFIA) is an airplane mounted with an infrared telescope that can fly above more than 99 percent of Earth's atmospheric water vapor. Unlike most space observatories, SOFIA can be routinely upgraded and repaired. It can look at planetary-forming systems and has recently observed its first exoplanet transit.
What’s Coming Next?
Analyzing the chemical makeup of Earth-sized, rocky planets with thin atmospheres is a big challenge, since smaller planets are incredibly faint compared to their stars. One solution is to block the light of the planets' glaring stars so that we can directly see the reflected light of the planets. Telescope instruments called coronagraphs use masks to block the starlight while letting the planet's light pass through. Another possible tool is a large, flower-shaped structure known as the starshade. This structure would fly in tandem with a space telescope to block the light of a star before it enters the telescope.
All images (except SOFIA) are artist illustrations.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com