Tarantula Nebula by NASA Hubble
This glittery spray of ancient stars is about 16,700 light-years away from Earth toward the constellation Tucana. Globular clusters like this one are isolated star cities, home to hundreds of thousands of stars that are held together by their mutual gravity. And like the fast pace of cities, there’s plenty of action in these stellar metropolises. The stars are in constant motion, orbiting around the cluster’s center.
Past observations have shown that the heavyweight stars tend to crowd into the “downtown” core area, while lightweight stars reside in the less populated suburbs. But as heavyweight stars age, they rapidly lose mass, cool down and shut off their nuclear furnaces. After the purge, only the stars’ bright, superhot cores – called white dwarfs – remain. This weight loss program causes the now lighter-weight white dwarfs to be nudged out of the downtown area through gravitational interactions with heftier stars.
Until these Hubble observations, astronomers had never seen the dynamic conveyor belt in action. The Hubble results reveal young white dwarfs amid their leisurely 40-million-year exodus from the bustling center of the cluster.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
(WARNING: Don’t try any of this on Earth—except the last one.)
Janssen aka 55 Cancri e
Hang your steak on a fishing pole and dangle your meat over the boiling pools of lava on this possible magma world. Try two to three minutes on each side to get an ashy feast of deliciousness.
Dimidium aka 51 Pegasi b
Set your grill to 1800 degrees Fahrenheit (982 degrees Celsius) or hop onto the first exoplanet discovered and get a perfect char on your hot dogs. By the time your dogs are done, it’ll be New Year’s Eve, because a year on this planet is only four days long.
HD 40307 g
Super air fry your duck on this Super Earth, as you skydive in the intense gravity of a planet twice as massive as Earth. Why are you air frying a duck? We don’t know. Why are you skydiving on an exoplanet? We’re not judging.
HAT-P-11b
I’ve got steaks, they’re multiplying/and I’m looooosing control. Cause the power this planet is supplying/is electrifying!
Sear your tuna to perfection in the lightning strikes that could flash across the stormy skies of this Neptune-like planet named HAT-P-11b.
Kepler-186f
Tired of all that meat? Try a multi-colored salad with the vibrant plants that could grow under the red sun of this Earth-sized planet. But it could also be a lifeless rock, so BYOB (bring your own barbecue).
Kepler-70b
Don’t take too long to prep your vegetables for the grill! The hottest planet on record will flash-incinerate your veggies in seconds!
WASP-12b
Picture this: You are pressure cooking your chicken on a hot gas giant in the shape of an egg. And you’re under pressure to cook fast, because this gas giant is being pulled apart by its nearby star.
Kepler-16b
Evenly cook your ribs in a dual convection oven under the dual stars of this “Tatooine.” Kick back and watch your two shadows grow in the fading light of a double sunset.
Venus
Order in for a staycation in our own solar system. The smell of rotten eggs rising from the clouds of sulfuric acid and choking carbon dioxide will put you off cooking, so get that meal to go.
Earth
Sometimes the best vacations are the ones you take at home. Flip your burgers on the only planet where you can breathe the atmosphere.
Grill us on Twitter and tell us how bad our jokes are.
Read the full version of this week’s ‘Solar System: 10 Things to Know’ Article HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
I had a really stupid idea and had to paint it for a friend.
In order to understand what is a brown dwarf, we need to understand the difference between a star and a planet. It is not easy to tell a star from a planet when you look up at the night sky with your eyes. However, the two kinds of objects look very different to an astronomer using a telescope or spectroscope. Planets shine by reflected light; stars shine by producing their own light. So what makes some objects shine by themselves and other objects only reflect the light of some other body? That is the important difference to understand – and it will allow us to understand brown dwarfs as well.
As a star forms from a cloud of contracting gas, the temperature in its center becomes so large that hydrogen begins to fuse into helium – releasing an enormous amount of energy which causes the star to begin shining under its own power. A planet forms from small particles of dust left over from the formation of a star. These particles collide and stick together. There is never enough temperature to cause particles to fuse and release energy. In other words, a planet is not hot enough or heavy enough to produce its own light.
Brown dwarfs are objects which have a size between that of a giant planet like Jupiter and that of a small star. In fact, most astronomers would classify any object with between 13 times the mass of Jupiter and 75 times the mass of Jupiter to be a brown dwarf. Given that range of masses, the object would not have been able to sustain the fusion of hydrogen like a regular star; thus, many scientists have dubbed brown dwarfs as “failed stars”.
This artist’s conception illustrates what brown dwarfs of different types might look like to a hypothetical interstellar traveler who has flown a spaceship to each one. Brown dwarfs are like stars, but they aren’t massive enough to fuse atoms steadily and shine with starlight – as our sun does so well.
On the left is an L dwarf, in the middle is a T dwarf, and on the right is a Y dwarf. The objects are progressively cooler in atmospheric temperatures as you move from left to right. Y dwarfs are the newest and coldest class of brown dwarfs and were discovered by NASA’s Wide-field Infrared Survey Explorer, or WISE. WISE was able to detect these Y dwarfs for the first time because it surveyed the entire sky deeply at the infrared wavelengths at which these bodies emit most of their light. The L dwarf is seen as a dim red orb to the eye. The T dwarf is even fainter and appears with a darker reddish, or magenta, hue. The Y dwarf is dimmer still. Because astronomers have not yet detected Y dwarfs at the visible wavelengths we see with our eyes, the choice of a purple hue is done mainly for artistic reasons. The Y dwarf is also illustrated as reflecting a faint amount of visible starlight from interstellar space.
In this rendering, the traveler’s spaceship is the same distance from each object. This illustrates an unusual property of brown dwarfs – that they all have the same dimensions, roughly the size of the planet Jupiter, regardless of their mass. This mass disparity can be as large as fifteen times or more when comparing an L to a Y dwarf, despite the fact that both objects have the same radius. The three brown dwarfs also have very different atmospheric temperatures. A typical L dwarf has a temperature of 2,600 degrees Fahrenheit (1,400 degrees Celsius). A typical T dwarf has a temperature of 1,700 degrees Fahrenheit (900 degrees Celsius). The coldest Y dwarf so far identified by WISE has a temperature of less than about 80 degrees Fahrenheit (25 degrees Celsius).
Sources: starchild.gsfc.nasa.gov & nasa.gov
image credit: NASA / JPL-Caltech
Archaeologists have uncovered a total of 250 cairn circles in southern India’s trade and industrial center of Kodumanal, which was inhabited from the 400s through first century B.C.E.
The cairn circles were made of giant rocks, or megaliths. Most of the cairn circles were around rectangular chambers built of megaliths, which in turn contained burial cists and three or four bowls or pots. The pottery was likely for offerings placed outside the burial cists, showing a belief system that included something after death.
An impressive ten pots and bowls were recently unearthed in a larger circle made of boulders and rectangular-shaped cists made of stone slabs, surrounding a three-chambered burial. This larger, more complex burial might have been intended for someone important in the community.
Gamma-ray bursts are the brightest, most violent explosions in the universe, but they can be surprisingly tricky to detect. Our eyes can’t see them because they are tuned to just a limited portion of the types of light that exist, but thanks to technology, we can even see the highest-energy form of light in the cosmos — gamma rays.
So how did we discover gamma-ray bursts?
Accidentally!
We didn’t actually develop gamma-ray detectors to peer at the universe — we were keeping an eye on our neighbors! During the Cold War, the United States and the former Soviet Union both signed the Nuclear Test Ban Treaty of 1963 that stated neither nation would test nuclear weapons in space. Just one week later, the US launched the first Vela satellite to ensure the treaty wasn’t being violated. What they saw instead were gamma-ray events happening out in the cosmos!
Things Going Bump in the Cosmos
Each of these gamma-ray events, dubbed “gamma-ray bursts” or GRBs, lasted such a short time that information was very difficult to gather. For decades their origins, locations and causes remained a cosmic mystery, but in recent years we’ve been able to figure out a lot about GRBs. They come in two flavors: short-duration (less than two seconds) and long-duration (two seconds or more). Short and long bursts seem to be caused by different cosmic events, but the end result is thought to be the birth of a black hole.
Short GRBs are created by binary neutron star mergers. Neutron stars are the superdense leftover cores of really massive stars that have gone supernova. When two of them crash together (long after they’ve gone supernova) the collision releases a spectacular amount of energy before producing a black hole. Astronomers suspect something similar may occur in a merger between a neutron star and an already-existing black hole.
Long GRBs account for most of the bursts we see and can be created when an extremely massive star goes supernova and launches jets of material at nearly the speed of light (though not every supernova will produce a GRB). They can last just a few seconds or several minutes, though some extremely long GRBs have been known to last for hours!
A Gamma-Ray Burst a Day Sends Waves of Light Our Way!
Our Fermi Gamma-ray Space Telescope detects a GRB nearly every day, but there are actually many more happening — we just can’t see them! In a GRB, the gamma rays are shot out in a narrow beam. We have to be lined up just right in order to detect them, because not all bursts are beamed toward us — when we see one it’s because we’re looking right down the barrel of the gamma-ray gun. Scientists estimate that there are at least 50 times more GRBs happening each day than we detect!
So what’s left after a GRB — just a solitary black hole? Since GRBs usually last only a matter of seconds, it’s very difficult to study them in-depth. Fortunately, each one leaves an afterglow that can last for hours or even years in extreme cases. Afterglows are created when the GRB jets run into material surrounding the star. Because that material slows the jets down, we see lower-energy light, like X-rays and radio waves, that can take a while to fade. Afterglows are so important in helping us understand more about GRBs that our Neil Gehrels Swift Observatory was specifically designed to study them!
Last fall, we had the opportunity to learn even more from a gamma-ray burst than usual! From 130 million light-years away, Fermi witnessed a pair of neutron stars collide, creating a spectacular short GRB. What made this burst extra special was the fact that ground-based gravitational wave detectors LIGO and Virgo caught the same event, linking light and gravitational waves to the same source for the first time ever!
For over 10 years now, Fermi has been exploring the gamma-ray universe. Thanks to Fermi, scientists are learning more about the fundamental physics of the cosmos, from dark matter to the nature of space-time and beyond. Discover more about how we’ll be celebrating Fermi’s achievements all year!
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Okay, the title of The Atlantic’s article might be a little click-bait-y. But the discovery is truly remarkable. A new bone has been analyzed from the already-famous cave in Russia, and it belonged to, per DNA analysis, the daughter of a Neanderthal mother and a Denisovan father.
The Aurora Named STEVE by NASA Goddard Photo and Video
Amateur astronomer, owns a telescope. This is a side blog to satiate my science-y cravings! I haven't yet mustered the courage to put up my personal astro-stuff here. Main blog : @an-abyss-called-life
212 posts