Fillthevoid-with-space - Fill The Void With... SPACE

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.

LUCIDA 

[noun] 

the brightest star in a constellation.

Etymology: from the full phrase in Latin stella lūcida meaning “bright star”. Lucida can be traced to the Latin verb lūcēre, "to shine,“ from lux, "light.”

[Tim Barton - Amber of the Void]

I just watched the 4 clearly visible planets march across the sky with the moon in the center, so here’s a short guide to the night sky as the last 3 move across.

mammenxTime lapse of the milky way rolling across the night sky, flanked by the planets Jupiter, Saturn & Mars. Taken from Diskit Ladakh, this place truly has some fantastic unobstructed views of the night sky

How hard is it to become an austronaut? I want to start to studie astrophysics and I don't know if I'll ever get any kind of job. Do you have any tips for people like me?

Astrophysics is a perfect field for pursuing any work at NASA!  A degree in a STEM field is a requirement of becoming an astronaut, but other than that there are many possibilities.  One of the best things about the astronaut office is its diversity.  We are scientists, engineers, military pilots, flight test engineers, medical doctors, etc. etc. My biggest tip is to ensure you are pursuing what it is you are passionate about as that’s the only way to truly become exceptional at what you are doing, and most importantly, to be happy doing it.  Passion, hard work, and dedication will get you there.  Good luck!

Ep. 34 Stargazing - HD and the Void

Not enough people in the real world listened to my stories about my recent stargazing adventure, so I distilled my process and plans so that the process of selecting a site and using a stargazing app seems more attainable for those who have never ...

I went stargazing in early August of this year (2019) and I want to suggest a few options that will hopefully make this sort of trip accessible to people who are curious about stargazing but haven’t tried it yet. I talk through the process of finding the right time and location, selecting campsites, preparing some tools to maintain your nightvision, and using an app to figure out stars and constellations more easily.

Below the cut are the transcript, sources, and music credits. Send me any topic suggestions via Tumblr message (you don’t need an account to do this, just submit as anonymous). You can also tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me in real life. Subscribe on iTunes to get the new episodes of my semi-monthly podcast, and I’d love if you could rate and review it. Go ahead and tell friends if you think they’d like to hear it, too!

(The next episode is undecided, but I’m hoping to have it out for September.)

Transcript

Sources

Dark Site Finder

SkyView Lite

Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity

Filler Music: me singing ‘House of Gold’ by Twenty-One Pilots off their album Vessel

me singing a parody of ‘Mexican Wine’ by Fountains of Wayne off their album Welcome Interstate Managers

Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught

How much of a daily threat is "Space junk"?

Good question, as this is a serious issue and one which we must monitor constantly in order to avoid harmful impacts on the International Space Station with objects in space.  For example, the US Space Command in Colorado is monitoring all objects bigger than a few inches in order to assess any potential impact with the Space Station.  We categorize the chance of impact and if there is a high probability, we will actually use thrusters to slightly change the position of the Space Station to avoid the impact.  If it is something that we are unable to avoid, we will have the astronauts shelter in place in their spacecrafts and in case of a catastrophic impact, they will return to Earth.

This photo of Astronaut Charlie Duke’s family has been on the moon for the last 43 years.

via reddit

Geocentric map of the Solar System.

It’s a long ways down. This is a view from the vantage point of astronaut Shane Kimbrough during his spacewalk last Friday outside the International Space Station. Shane posted this photo and wrote, “ View of our spectacular planet (and my boots) during the #spacewalk yesterday with @Thom_astro.” During the spacewalk with Kimbrough and Thomas Pesquet of ESA, which lasted just over six-and-a-half hours, the two astronauts successfully disconnected cables and electrical connections to prepare for its robotic move Sunday, March 26.

Two astronauts will venture outside the space station again this Thursday, March 30 for the second of three spacewalks. Kimbrough and Flight Engineer Peggy Whitson will begin spacewalk preparation live on NASA Television starting at 6:30 a.m. EST, with activities beginning around 8 a.m. Watch live online here.

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

Comet That Took a Century to Confirm Passes by Earth

NASA Goddard Space Flight Center logo. March 31, 2017 On April 1, 2017, comet 41P will pass closer than it normally does to Earth, giving observers with binoculars or a telescope a special viewing opportunity. Comet hunters in the Northern Hemisphere should look for it near the constellations Draco and Ursa Major, which the Big Dipper is part of. Whether a comet will put on a good show for observers is notoriously difficult to predict, but 41P has a history of outbursts, and put on quite a display in 1973. If the comet experiences similar outbursts this time, there’s a chance it could become bright enough to see with the naked eye. The comet is expected to reach perihelion, or its closest approach to the sun, on April 12.

Image above: In this image taken March 24, 2017, comet 41P/Tuttle-Giacobini-Kresák is shown moving through a field of faint galaxies in the bowl of the Big Dipper. On April 1, the comet will pass by Earth at a distance of about 13 million miles (0.14 astronomical units), or 55 times the distance from Earth to the moon; that is a much closer approach than usual for this Jupiter-family comet. Image Credits: image copyright Chris Schur, used with permission. Officially named 41P/Tuttle-Giacobini-Kresák to honor its three discoverers, the comet is being playfully called the April Fool’s Day comet on this pass. Discovery credit goes first to Horace Tuttle, who spotted the comet in 1858. According to the Cometography website, 41P was recognized at the time as a periodic comet — one that orbits the sun — but astronomers initially were uncertain how long the comet needed to make the trip. The comet was rediscovered in 1907 by Michael Giacobini but not immediately linked to the object seen in 1858. Later, the astronomer Andrew Crommelin determined that the two observations had been of the same object and predicted that the comet would return in 1928 and 1934, according to the Cometography entry for the comet. However, the object was not seen then and was considered lost. In 1951, L’ubor Kresák discovered it again and tied it to the earlier observations. A member of the Jupiter family of comets, 41P makes a trip around the sun every 5.4 years, coming relatively close to Earth on some of those trips. On this approach, the comet will pass our planet at a distance of about 13 million miles (0.14 astronomical units), or about 55 times the distance from Earth to the moon. This is the comet’s closest approach to Earth in more than 50 years and perhaps more than a century. For scientists, 41P’s visit is an opportunity to fill in details about the comet’s composition, coma and nucleus.

Image above: An artist’s illustration of a group of comet enthusiasts. Image Credits: NASA’s Goddard Space Flight Center. “An important aspect of Jupiter-family comets is that fewer of them have been studied, especially in terms of the composition of ices in their nuclei, compared with comets from the Oort cloud,” said Michael DiSanti of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. He and his team will be observing 41P on April 1 using NASA’s Infrared Telescope Facility in Hawaii. Astronomers will try to determine characteristics such as how quickly 41P’s nucleus rotates, which provides clues about how structurally sound the nucleus is, and whether any changes can be documented in the coma and tail. Observers also will look for outbursts, which are an indication of how active a comet is. By cataloging the subtle, and sometimes not-so-subtle, differences among comets, researchers can construct a family tree and trace the history of how and where these objects formed as the solar system was taking shape. “Comets are remnants from the early solar system,” said DiSanti. “Each comet that comes into the neighborhood of Earth gives us a chance to add to our understanding of the events that led to the formation of our own planet.” Related links: Comets: http://www.nasa.gov/comets Goddard Space Flight Center: https://www.nasa.gov/centers/goddard/home/index.html Images (mentioned), Text, Credits: NASA’s Goddard Space Flight Center, by Elizabeth Zubritsky/Rob Garner. Greetings, Orbiter.ch Full article