Located In The Large Magellanic Cloud, One Of Our Neighbouring Dwarf Galaxies, This Young Globular-like

Ghost Nebula

Enceladus

Enceladus is one of the major inner moons of Saturn along with Dione, Tethys, and Mimas. It orbits Saturn at a distance of 148,000 miles (238,000 km), falling between the orbits of Mimas and Tethys. It is tidally locked with Saturn, keeping the same face toward the planet. It completes one orbit every 32.9 hours within the densest part of Saturn’s E Ring, the outermost of its major rings, and is its main source.

Enceladus is, like many moons in the extensive systems of the giant planets, trapped in an orbital resonance. Its resonance with Dione excites its orbital eccentricity, which is damped by tidal forces, tidally heating its interior, and possibly driving the geological activity.

Enceladus is Saturn’s sixth largest moon, only 157 miles (252 km) in mean radius, but it’s one of the most scientifically compelling bodies in our solar system. Hydrothermal vents spew water vapor and ice particles from an underground ocean beneath the icy crust of Enceladus. This plume of material includes organic compounds, volatile gases, carbon dioxide, carbon monoxide, salts and silica.

With its global ocean, unique chemistry and internal heat, Enceladus has become a promising lead in our search for worlds where life could exist.

In 2005, Cassini’s multiple instruments discovered that this icy outpost is gushing water vapor geysers out to a distance of three times the radius of Enceladus. The icy water particles are roughly one ten-thousandth of an inch, or about the width of a human hair. The particles and gas escape the surface at jet speed at approximately 800 miles per hour (400 meters per second). The eruptions appear to be continuous, refreshing the surface and generating an enormous halo of fine ice dust around Enceladus, which supplies material to one of Saturn’s rings, the E-ring.

Several gases, including water vapor, carbon dioxide, methane, perhaps a little ammonia and either carbon monoxide or nitrogen gas make up the gaseous envelope of the plume.

Read more at: solarsystem.nasa.gov

Image credit: NASA/JPL/Cassini & Kevin Gill

Messier 82

Messier 82 is a starburst galaxy about 12 million light-years away in the constellation Ursa Major. A member of the M81 Group, it is about five times more luminous than the whole Milky Way and has a center one hundred times more luminous than our galaxy’s center.

Image credit: NASA/ESA & Hubble

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.

Image of Saturn taken by the Cassini spacecraft in 2013

Image credit: NASA / JPL-Caltech 

Tomorrow one of the most prolific and beloved spacecraft missions will come to an end when the Cassini spacecraft makes its final plunge into Saturn. After nearly 20 years in space and 13 years orbiting Saturn, the Cassini mission is close to running out of fuel. To prevent the craft from contaminating one of Saturn’s moons – which its mission revealed may harbor the ingredients for life – mission operators are instead sending it on a fatal dive into the gas giant. 

Cassini has and will continue to provide a trove of scientific insights about Saturn and its environs. It has given us front-row seats to a storm that wrapped around the entire planet. It shed new light on Saturn’s spectacular hexagonal polar vortex and showed us the beauty of auroras on other planets. Cassini also showed us that Saturn’s moon Titan has stable hydrocarbon lakes at its surface, fed by methane rains and driven by processes unfamiliar to terrestrial ones. It also gave us paths for future exploration by documenting plumes of water ejected from Enceladus’ icebound oceans.

Cassini also holds a special place in my heart. It launched while I was in middle school, reached Jupiter while I was in college, and collected data throughout my postgraduate research career. It was an inspiration for my undergraduate spacecraft mission design projects, and it provided fun and exciting fluid dynamical discoveries throughout my time writing FYFD. It’s my favorite mission (sorry, Mars rovers, New Horizons, Dawn, and Juno!) and likely to remain so for years to come.

So thank you, Cassini, and many thanks to all the scientists, engineers, and operators who’ve worked on the mission during the decades from its conception to completion. You did a hell of a job. Godspeed, Cassini! (Photo credits: NASA/JPL)

P.S. - Tonight I’ll be helping kick off the Ig Nobel Prize ceremony. You can tune into the live webcast here. The ceremony officially starts at 6 PM Eastern time, but I recommend tuning in early, especially if you want to catch my full spiel. - Nicole 

Hubble Sees the Force Awakening in a Newborn Star

This celestial lightsaber does not lie in a galaxy far, far away, but rather inside our home galaxy, the Milky Way. It’s inside a turbulent birthing ground for new stars known as the Orion B molecular cloud complex, located 1,350 light-years away.

In the center of the image, partially obscured by a dark, Jedi-like cloak of dust, a newborn star shoots twin jets out into space as a sort of birth announcement to the universe

Credit: NASA/ESA

R Aquarii is known as a symbiotic star made up of a white dwarf–red giant binary pairing. These two stars are tied in orbit around one another with a period of around 44 years. The primary star is a variable red giant, meaning it changes temperature and undergoes drastic brightness fluctuations. The secondary star is a white dwarf that sucks in material from the red giant. Some of the extra material is sometimes ejected, forming the incredibly stunning nebula surrounding it.

(Credit: Hubble Space Telescope/Judy Schmidt)

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.