Glossary

Raising the bar for antimatter exploration

CERN - European Organization for Nuclear Research logo.  March 18, 2017 The absence of antimatter in the universe is a long-standing jigsaw puzzle in physics. Many experiments have been exploring this question by finding asymmetries between particles and their antimatter counterparts. GBAR (Gravitational Behaviour of Antihydrogen at Rest), a new experiment at CERN, is preparing to explore one aspect of this puzzle – what is the effect of gravity on antimatter? While theories exist as to whether antimatter will behave like matter or not, a definitive experimental result is still missing.

Image above: Installation of the GBAR linac in its shielding bunker. The electrons accelerated to 10 MeV toward a target will produce the positrons that are necessary to form antihydrogen with the antiprotons coming from the ELENA decelerator. (Image: Max Brice/CERN). GBAR will measure the effect of gravity on antihydrogen atoms. Located in the Antiproton Decelerator (AD) hall, GBAR is the first of five experiments that will be connected to the new ELENA deceleration ring. On 1 March, the first component of the experiment was installed – a linear accelerator (linac). In sharp contrast to the LHC’s chain of big accelerators and fast particles, the AD world of antimatter is small and its particles are as slow as they come. The GBAR linac is only 1.2 metres long and it will be used to create positrons, the antimatter equivalent of electrons. The experiment will use antiprotons supplied by ELENA and positrons created by the linac to produce antihydrogen ions. They consist of one antiproton and two positrons, and their positive charge makes them significantly easier to manipulate. With the help of lasers, their velocity will be reduced to half a metre per second. This will allow them to be directed to a fixed point. Then, trapped by an electric field, one of their positrons will be removed with a laser, which will make them neutral again. The only force acting on them at this point will be gravity and they will be free to make a 20-centimetre fall, during which researchers will observe their behaviour. The results might turn out to be very exciting. As the spokesperson of GBAR, Patrice Pérez, explains: “Einstein’s Equivalence Principle states that the trajectory of a particle is independent of its composition and internal structure when it is only submitted to gravitational forces. If we find out that gravity has a different effect on antimatter, this would mean that we still have a lot to learn about the universe.” Five other experiments are based at the Antiproton Decelerator, two of which – AEGIS and ALPHA – are also studying the effect of gravity on antimatter. Note: CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature. The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions. Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States. Related links: GBAR (Gravitational Behaviour of Antihydrogen at Rest): https://gbar.web.cern.ch/GBAR/public/index.html Antiproton Decelerator (AD): https://home.cern/about/accelerators/antiproton-decelerator ELENA: http://home.cern/about/updates/2016/11/new-ring-slow-down-antimatter linear accelerator (linac): http://home.cern/tags/linear-accelerator AEGIS: http://home.cern/about/experiments/aegis ALPHA: https://home.cern/about/experiments/alpha For more information about European Organization for Nuclear Research (CERN), Visit: http://home.cern/ Image (mentioned), Text, Credits: CERN/Iva Raynova. Greetings, Orbiter.ch Full article

Galaxy NGC 7714 After Collision : Is this galaxy jumping through a giant ring of stars? Probably not. Although the precise dynamics behind the featured image is yet unclear, what is clear is that the pictured galaxy, NGC 7714, has been stretched and distorted by a recent collision with a neighboring galaxy. This smaller neighbor, NGC 7715, situated off to the left of the featured frame, is thought to have charged right through NGC 7714. Observations indicate that the golden ring pictured is composed of millions of older Sun-like stars that are likely co-moving with the interior bluer stars. In contrast, the bright center of NGC 7714 appears to be undergoing a burst of new star formation. NGC 7714 is located about 100 million light years away toward the constellation of the Fish . The interactions between these galaxies likely started about 150 million years ago and should continue for several hundred million years more, after which a single central galaxy may result. via NASA

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The 10-billion-year life cycle of the Sun, illustrated by David Meltzer for National Geographic, May 1974.

It’s international dark sky week! Please enjoy this great Bortle scale.

skyglowproject What sky do you live under? Learn more at SKYGLOWPROJECT.COM

The Cassini probe took a picture of Saturn that includes Earth in it!

Cassini has actually taken a ton of cool photos of Saturn if you want to check those out in the wake of last week’s planets podcast. 

No matter where you hang your stockings, I wish you a very Merry Christmas!

Why Webb Needs to Chill

Our massive James Webb Space Telescope is currently being tested to make sure it can work perfectly at incredibly cold temperatures when it’s in deep space. 

How cold is it getting and why? Here’s the whole scoop…

Webb is a giant infrared space telescope that we are currently building. It was designed to see things that other telescopes, even the amazing Hubble Space Telescope, can’t see.  

Webb’s giant 6.5-meter diameter primary mirror is part of what gives it superior vision, and it’s coated in gold to optimize it for seeing infrared light.  

Why do we want to see infrared light?

Lots of stuff in space emits infrared light, so being able to observe it gives us another tool for understanding the universe. For example, sometimes dust obscures the light from objects we want to study – but if we can see the heat they are emitting, we can still “see” the objects to study them.

It’s like if you were to stick your arm inside a garbage bag. You might not be able to see your arm with your eyes – but if you had an infrared camera, it could see the heat of your arm right through the cooler plastic bag.

Credit: NASA/IPAC

With a powerful infrared space telescope, we can see stars and planets forming inside clouds of dust and gas.

We can also see the very first stars and galaxies that formed in the early universe. These objects are so far away that…well, we haven’t actually been able to see them yet. Also, their light has been shifted from visible light to infrared because the universe is expanding, and as the distances between the galaxies stretch, the light from them also stretches towards redder wavelengths. 

We call this phenomena  “redshift.”  This means that for us, these objects can be quite dim at visible wavelengths, but bright at infrared ones. With a powerful enough infrared telescope, we can see these never-before-seen objects.

We can also study the atmospheres of planets orbiting other stars. Many of the elements and molecules we want to study in planetary atmospheres have characteristic signatures in the infrared.

Because infrared light comes from objects that are warm, in order to detect the super faint heat signals of things that are really, really far away, the telescope itself has to be very cold. How cold does the telescope have to be? Webb’s operating temperature is under 50K (or -370F/-223 C). As a comparison, water freezes at 273K (or 32 F/0 C).

How do we keep the telescope that cold? 

Because there is no atmosphere in space, as long as you can keep something out of the Sun, it will get very cold. So Webb, as a whole, doesn’t need freezers or coolers - instead it has a giant sunshield that keeps it in the shade. (We do have one instrument on Webb that does have a cryocooler because it needs to operate at 7K.)

Also, we have to be careful that no nearby bright things can shine into the telescope – Webb is so sensitive to faint infrared light, that bright light could essentially blind it. The sunshield is able to protect the telescope from the light and heat of the Earth and Moon, as well as the Sun.  

Out at what we call the Second Lagrange point, where the telescope will orbit the Sun in line with the Earth, the sunshield is able to always block the light from bright objects like the Earth, Sun and Moon.

How do we make sure it all works in space? 

By lots of testing on the ground before we launch it. Every piece of the telescope was designed to work at the cold temperatures it will operate at in space and was tested in simulated space conditions. The mirrors were tested at cryogenic temperatures after every phase of their manufacturing process.

The instruments went through multiple cryogenic tests at our Goddard Space Flight Center in Maryland.

Once the telescope (instruments and optics) was assembled, it even underwent a full end-to-end test in our Johnson Space Center’s giant cryogenic chamber, to ensure the whole system will work perfectly in space.  

What’s next for Webb? 

It will move to Northrop Grumman where it will be mated to the sunshield, as well as the spacecraft bus, which provides support functions like electrical power, attitude control, thermal control, communications, data handling and propulsion to the spacecraft.

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

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115th Anniversary of the Antikythera Mechanism's Discovery

Today's Google Doodle

On this date in 1902, Greek archaeologist Valerios Stais sifted through some artifacts from a shipwreck at Antikythera. The wrecked Roman cargo ship was discovered two years earlier, but Stais was the first to notice an intriguing bit of bronze among the treasures. It looked like it might be a gear or wheel. That corroded chunk of metal turned out to be part of the Antikythera Mechanism, an ancient analog astronomical computer.

The Antikythera Mechanism tracked planetary positions, predicted lunar and solar eclipses, and even signaled the next Olympic Games. It was probably also used for mapping and navigation. A dial on the front combines zodiacal and solar calendars, while dials on the back capture celestial cycles. Computer models based on 3-D tomography have revealed more than 30 sophisticated gears, housed in a wooden and bronze case the size of a shoebox.  

“As the centuries unfold, millions of artists will live on the moon and paint the moon and Mars as we go out into the universe.”

Today we remember the fourth man to walk on the moon. Astronaut Alan Bean passed away in Houston, at the age of 86.

Bean was the lunar module pilot for Apollo 12 in November 1969, and was commander of Skylab 3 in June 1973. He retired from NASA in 1981 to devote his time to painting.