@maevemauvaise

What’s hard about Mars?

Mars, unlike the Moon, is far away. It also has an atmosphere - but not a useful one. Atmospheric density, wind, dust storms… all of these things contribute to a larger list of circumstances that any given mission needs to be ready for.

All those circumstances contribute heavily to the cost, time and hard resources needed to be poured into the mission preparation. In addition, the vast distance to Mars means the cost of carrying all this prepared hardware must be covered.

The atmosphere of Mars is such that if you’re going too fast during entry, you’ll burn up. It’s such a low density however that parachutes aren’t tremendously useful.

During the Curiosity rover’s landing it needed a heat shield, a supersonic parachute, rocket boosters to slow it down, a sky-crane to allow Curiosity to drop to the surface like an interplanetary spider and then explosive propulsion to send the platform it dropped from a safe distance away to crash into the surface.

During this landing, the rover experienced a force of about 15 g’s. That force would make a 200 lb man weigh 3000 lbs. Without proper precautions it would make the average head snap down at about 150 to 165 lbs.

NASA’s developing a new type of parachute and it’s being attached to a flying saucer-like spacecraft known as the Low-Density Supersonic Decelerator. This is currently hoped to provide NASA with a stable go-to architecture for future Mars missions.

The red planet’s killed most missions sent there. Power for solar-panels on rovers get covered during planet-wide dust storms. Some missions smashed into its moons. Some have smashed into its surface. Others have simply missions the planet entirely only to drift away as Mars dances around the Sun.

The world is an untamed place and has sought to buck all attempts to temper its mysteries.  

(Image credit: ESA / DLR / FU Berlin (G. Neukum) / animation by Emily Lakdawalla)

@little-laced Here are some test shots I took of the moon. It’s hard to tell because I had to reduce the image size drastically but the telescope was extremely difficult to keep focused. The image quality loss I incurred uploading this only adds to the ‘out-of-focus’ness

Also shout out to the Sea of Crises visible as the circular, dark-gray splotch on the right

What caused this outburst of this star named V838 Mon? For reasons unknown, this star’s outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this had never been seen before – supernovas and novas expel matter out into space.

Although the V838 Mon flash appears to expel material into space, what is seen in the above GIF from the Hubble Space Telescope is actually an outwardly moving light echo of the bright flash.

In a light echo, light from the flash is reflected by successively more distant rings in the complex array of ambient interstellar dust that already surrounded the star. V838 Mon lies about 20,000 light years away toward the constellation of the unicorn (Monoceros), while the light echo above spans about six light years in diameter.

Credit: NASA, ESA

To discover more, visit: https://www.nasa.gov/multimedia/imagegallery/image_feature_2472.html

The beautiful chaos of watching 12 frantic astrophysics students try to save a theoretical astronaut from falling into a black hole. I’ve never seen a group of people work so quickly and efficiently before.

When Dead Stars Collide!

Gravity has been making waves - literally.  Earlier this month, the Nobel Prize in Physics was awarded for the first direct detection of gravitational waves two years ago. But astronomers just announced another huge advance in the field of gravitational waves - for the first time, we’ve observed light and gravitational waves from the same source.

There was a pair of orbiting neutron stars in a galaxy (called NGC 4993). Neutron stars are the crushed leftover cores of massive stars (stars more than 8 times the mass of our sun) that long ago exploded as supernovas. There are many such pairs of binaries in this galaxy, and in all the galaxies we can see, but something special was about to happen to this particular pair.

Each time these neutron stars orbited, they would lose a teeny bit of gravitational energy to gravitational waves. Gravitational waves are disturbances in space-time - the very fabric of the universe - that travel at the speed of light. The waves are emitted by any mass that is changing speed or direction, like this pair of orbiting neutron stars. However, the gravitational waves are very faint unless the neutron stars are very close and orbiting around each other very fast.

As luck would have it, the teeny energy loss caused the two neutron stars to get a teeny bit closer to each other and orbit a teeny bit faster.  After hundreds of millions of years, all those teeny bits added up, and the neutron stars were *very* close. So close that … BOOM! … they collided. And we witnessed it on Earth on August 17, 2017.  

Credit: National Science Foundation/LIGO/Sonoma State University/A. Simonnet

A couple of very cool things happened in that collision - and we expect they happen in all such neutron star collisions. Just before the neutron stars collided, the gravitational waves were strong enough and at just the right frequency that the National Science Foundation (NSF)’s Laser Interferometer Gravitational-Wave Observatory (LIGO) and European Gravitational Observatory’s Virgo could detect them. Just after the collision, those waves quickly faded out because there are no longer two things orbiting around each other!

LIGO is a ground-based detector waiting for gravitational waves to pass through its facilities on Earth. When it is active, it can detect them from almost anywhere in space.

The other thing that happened was what we call a gamma-ray burst. When they get very close, the neutron stars break apart and create a spectacular, but short, explosion. For a couple of seconds, our Fermi Gamma-ray Telescope saw gamma-rays from that explosion. Fermi’s Gamma-ray Burst Monitor is one of our eyes on the sky, looking out for such bursts of gamma-rays that scientists want to catch as soon as they’re happening.

And those gamma-rays came just 1.7 seconds after the gravitational wave signal. The galaxy this occurred in is 130 million light-years away, so the light and gravitational waves were traveling for 130 million years before we detected them.

After that initial burst of gamma-rays, the debris from the explosion continued to glow, fading as it expanded outward. Our Swift, Hubble, Chandra and Spitzer telescopes, along with a number of ground-based observers, were poised to look at this afterglow from the explosion in ultraviolet, optical, X-ray and infrared light. Such coordination between satellites is something that we’ve been doing with our international partners for decades, so we catch events like this one as quickly as possible and in as many wavelengths as possible.

Astronomers have thought that neutron star mergers were the cause of one type of gamma-ray burst - a short gamma-ray burst, like the one they observed on August 17. It wasn’t until we could combine the data from our satellites with the information from LIGO/Virgo that we could confirm this directly.

This event begins a new chapter in astronomy. For centuries, light was the only way we could learn about our universe. Now, we’ve opened up a whole new window into the study of neutron stars and black holes. This means we can see things we could not detect before.

The first LIGO detection was of a pair of merging black holes. Mergers like that may be happening as often as once a month across the universe, but they do not produce much light because there’s little to nothing left around the black hole to emit light. In that case, gravitational waves were the only way to detect the merger.

Image Credit: LIGO/Caltech/MIT/Sonoma State (Aurore Simonnet)

The neutron star merger, though, has plenty of material to emit light. By combining different kinds of light with gravitational waves, we are learning how matter behaves in the most extreme environments. We are learning more about how the gravitational wave information fits with what we already know from light - and in the process we’re solving some long-standing mysteries!

Want to know more? Get more information HERE.

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

China's colossal radio telescope begins testing - BBC News

The world's largest radio telescope has received its first signals from space and is now entering an intensive testing phase.

Fantastic success story for the astronomy community of China, congratulations!

in 20-70 million years, Mars’ moon Phobos will get close enough to the surface of the planet that it will be ripped apart by the tidal forces. The resulting debris will most likely give Mars a planetary ring.

lol sometimes science publications are like 20 pages of gibberish. It feels like an alien language I’m learning slowly as I stare at the pages… 

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Creepy or adorable? Researchers at Harvard University have demonstrated the first autonomous, untethered, entirely soft robot: the octobot.

Instead of being controlled by electronics, the robot’s logic board is powered by chemical reactions and fluid passing along tiny channels. Scientist have struggled to create completely soft robots because rigid components like circuit boards, power sources and electronic controls are difficult to replace.  

Learn more about the octobot and soft robotics here and see the full study published in Nature here.

Videos Credit: Harvard SEAS/Image Credit Lori Sanders