ON THIS DAY: An Impressive Impact Crater On Mars, Observed By NASA’s Mars Reconnaissance Orbiter, November

Planet Jupiter, observed by the Juno probe on September 1, 2017.

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.

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

Io and Europa taken by the Voyager 1 spacecraft in 1979

Image credit: Justin Cowart

evosia Chasing auroras is much like living life: if you show up, always be prepared for the amazing to happen.

NASA’s Juno Probe Returns Stunning New Image of Jupiter

http://www.sci-news.com/space/juno-image-jupiter-05256.html

Ask Ethan: Why don’t we build a telescope without mirrors or lenses?

“Why do we need a lens and a mirror to make a telescope now that we have CCD sensors? Instead of having a 10m mirror and lens that focus the light on a small sensor, why not have a 10m sensor instead?”

Every time you shine light through a lens or reflect it off of a mirror, no matter how good it is, a portion of your light gets lost. Today’s largest, most powerful telescopes don’t even simply have a primary mirror, but secondary, tertiary, even quaternary or higher mirrors, and each of those reflections means less light to derive your data from. As CCDs and other digital devices are far more efficient than anything else, why couldn’t we simply replace the primary mirror with a CCD array to collect and measure the light? It seems like a brilliant idea on the surface, and it would, in fact, gather significantly more light over the same collecting area. True, CCDs are more expensive, and there are technical challenges as far as applying filters and aligning the array properly. But there’s a fundamental problem if you don’t use a mirror or lens at all that may turn out to be a dealbreaker: CCDs without lenses or mirrors are incapable of measuring the direction light is coming from. A star or galaxy would appear equally on all portions of your CCD array at once, giving you just a bright, white-light image on every single CCD pixel.

It’s a remarkable idea, but there’s a good physical reason why it won’t pan out. For the foreseeable future, we still need optics to make a telescope! Find out why on this week’s Ask Ethan.

Curiosity drill site reveals that under its red surface, Mars is grey-blue

via reddit

Coffee in Space: Keeping Crew Members Grounded in Flight

Happy National Coffee Day, coffee lovers! 

On Earth, a double shot mocha latte with soymilk, low-fat whip and a caramel drizzle is just about as complicated as a cup of coffee gets. Aboard the International Space Station, however, even just a simple cup of black coffee presents obstacles for crew members.

Understanding how fluids behave in microgravity is crucial to bringing the joys of the coffee bean to the orbiting laboratory. Astronaut Don Pettit crafted a DIY space cup using a folded piece of overhead transparency film. Surface tension keeps the scalding liquid inside the cup, and the shape wicks the liquid up the sides of the device into the drinker’s mouth.

The Capillary Beverage investigation explored the process of drinking from specially designed containers that use fluid dynamics to mimic the effect of gravity. While fun, this study could provide information useful to engineers who design fuel tanks for commercial satellites!

The capillary beverage cup allows astronauts to drink much like they would on Earth. Rather than drinking from a shiny bag and straw, the cup allows the crew member to enjoy the aroma of the beverage they’re consuming.

On Earth, liquid is held in the cup by gravity. In microgravity, surface tension keeps the liquid stable in the container.

The ISSpresso machine brought the comforts of freshly-brewed coffees and teas to the space station. European astronaut Samantha Cristoforetti enjoyed the first cup of espresso brewed using the ISSpresso machine during Expedition 43.

Now, during Expedition 53, European astronaut Paolo Nespoli enjoys the same comforts. 

Astronaut Kjell Lindgren celebrated National Coffee Day during Expedition 45 by brewing the first cup of hand brewed coffee in space.

We have a latte going on over on our Snapchat account, so give us a follow to stay up to date! Also be sure to follow @ISS_Research on Twitter for your daily dose of space station science.

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

If we ever want a long-distance relationship with aliens, they have to be able to find us.

2017 October 30

Orionid Meteors from Orion Image Credit & Copyright: Lu Shupei

Explanation: Meteors have been shooting out from the constellation of Orion. This was expected, as October is the time of year for the Orionids Meteor Shower. Pictured here, over a dozen meteors were caught in successively added exposures last weekend over Wulan Hada volcano in Inner Mongolia, China. The featured image shows multiple meteor streaks that can all be connected to a single small region on the sky called the radiant, here visible just above and to the left of the belt of Orion, The Orionids meteors started as sand sized bits expelled from Comet Halley during one of its trips to the inner Solar System. Comet Halley is actually responsible for two known meteor showers, the other known as the Eta Aquarids and visible every May. Next month, the Leonids Meteor Shower from Comet Tempel-Tuttle should also result in some bright meteor streaks.

∞ Source: apod.nasa.gov/apod/ap171030.html