The Black Swan (Cygnus Atratus) Is One Of My Favourite Birds, Mainly Because It’s Hella Gay. An Estimated

A giant #ammonite from millions of years ago. One of New Zealand’s largest fossils is on permanent display in Te Papa.

Daphnis and the Rings of Saturn : What’s happening to the rings of Saturn? A little moon making big waves. The moon is 8-kilometer Daphnis and it is making waves in the Keeler Gap of Saturn’s rings using just its gravity – as it bobs up and down, in and out. The featured image is a colored and more detailed version of a previously released images taken in 2017 by the robotic Cassini spacecraft during one of its Grand Finale orbits. Daphnis can be seen on the far right, sporting ridges likely accumulated from ring particles. Daphnis was discovered in Cassini images in 2005 and raised mounds of ring particles so high in 2009 – during Saturn’s equinox when the ring plane pointed directly at the Sun – that they cast notable shadows. via NASA

A ten billion-year stellar dance by europeanspaceagency

The night palatte 

Gamma-ray Bursts: Black Hole Birth Announcements

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!

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Kepler’s Supernova Remnant SN 1604 by Hubble Heritage

Hubble Observes Infant Stars in Nearby Galaxy by NASA Hubble

Lyrid Meteors

Sun’s corona during a solar-eclipse.

It makes me sad how no one ever seems to mention how wild the crocodilian-line archosaurs were. Dinosaurs get all the attention when there was equally crazy shit happening on the other branch of the archosaur tree.

There was a whole linage of bipedal crocodylomorphs during the Triassic that were basically identical to theropod dinosaurs, so much so that a lot of them were initially classified as dinosaurs!

Just fucking look at them!

And these weren’t just little lizard guys, there were some big lads running around.

Not to mention the long-legged ones that galloped around on all fours like some kind of terrifying reptilian dogs.

These crazy crocodiles aren’t just from the Triassic, either; there was a galloping, hoofed crocodilian that lived during the Eocene and likely hunted horses. (They were smaller and not quite as fast as modern horses, but still)

But don’t worry, they weren’t all meat-eaters! There were vegetarian and omnivore crocodylomorphs too! Just look at this guy!

He was an ankylosaur before ankylosaurs were cool (or even existed).