universe is expanding

The Aurebesh, an alphabet for the Star Wars universe, created by West End Games art director Stephen Crane for his Star Wars Miniatures Battles Companion rules supplement (1994).  The Aurebesh now appears in the canonical films, in phrases that can be transposed into English.

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.

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If The Universe Is Expanding, Then Why Aren’t We?

“You might then ask, at what distance does the expansion start to take over? That happens when you average over a volume so large that the density of matter inside the volume has a gravitational self-attraction weaker than the expansion’s pull. From atomic nuclei up, the larger the volume you average over, the smaller the average density. But it is only somewhere beyond the scales of galaxy clusters that expansion takes over. On very short distances, when the nuclear and electromagnetic forces aren’t neutralized, these also act against the pull of gravity. This safely prevents atoms and molecules from being torn apart by the universe’s expansion.”

The Universe is expanding. The farther away a galaxy is, the faster it appears to be receding from us. The standard story tells us that space itself is expanding, and that’s the cause, but it’s only natural to wonder if perhaps space is static, and everything else within it isn’t shrinking instead? Many laypersons choose to go this route, and question the entire field of cosmology as a result. But is this fair? Or is this a road to not only ruin, but to physical inconsistencies? Could we flip the story on its head, and do some sort of test to see if atoms, the planet, or some other ‘local’ entity is shrinking, instead? Or, using the principle of relativity, could we declare that all frames are equally valid, and choose a frame where space isn’t expanding, after all?

These are all interesting thoughts, but there’s only one correct, valid, and consistent way to view the Universe. Sabine Hossenfelder has the explanation!

Nothing in this Universe happens by chance. Everything happens for a reason. The good, the bad, tragic, and ecstatic, it all happens for a reason.

Between the Power Rangers movie, episode VIII, Spider-Man Homecoming, Justice League, Wonder Woman, Ragnarok, Guardians of the Galaxy and the Yu-Gi-Oh! film I feel like 2017’s nerdiest films are trying to apologize for Carrie Fisher’s death in 2016

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Entertainment Weekly has details for several Journey to Star Wars: The Last Jedi books. The new addition: A collection of short stories focusing on inhabitants of Canto Bight, the ritzy casino planet. The authors are Star Wars vet John Jackson Miller and franchise newcomers Saladin Ahmed, Rae Carson, and Mira Grant. It will be on shelves December 5.

We first heard about most of them back at Celebration, but there’s still plenty of mystery. Ken Liu’s The Legends of Luke Skywalker (October 31), which “presents its stories as rumors circulating through the galaxy.” Claudia Gray’s Leia: Princess of Alderaan (September 1) is set when the character is 16, when she “decides to become involved in the fight against the Empire.” We’ll also see plenty of her parents and friends, a boon for fans who want to know more about Alderaan.

Delilah S. Dawson’s Phasma (September 1) will, as we learned in Orlando, give us her origin story, going back to her youth. The book will “show how she got off the planet that she was on initially and came to the First Order and what did she have to do to get there and what will she do to protect her secrets,” Lucasfilm’s Michael Siglain says. “It cuts between the present and the past and shows her as this fearsome warrior on this brutal world that she was on. The First Order comes to that planet, and she sees a great opportunity when they arrive.”