What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. […]

What’s that passing in front of the Sun? It looks like a moon, but it can’t be Earth’s Moon, because it isn’t round. It’s the Martian moon Phobos. The featured […]

Sometimes Saturn disappears. It doesn’t really go away, though, it just disappears from view when our Moon moves in front. Such a Saturnian eclipse was visible along a small swath […]

After sunset on March 28, the International Space Station climbed above the western horizon, as seen from Wallasey, England at the mouth of the River Mersey. Still glinting in the […]

After the Crab Nebula, M1, this giant star cluster is the second entry in 18th century astronomer Charles Messier’s famous list of things with are not comets. M2 is one […]

The famous Horsehead Nebula in Orion is not alone. A deep exposure shows that the dark familiar shaped indentation, visible just below center, is part of a vast complex of […]

Score three points for NASA. With time running out late in Apollo 15’s mission to the Moon in 1971, Astronaut David Scott prepared to split the uprights and bring about […]

Put on your red/cyan glasses and float next to the jagged and double-lobed nucleus of Churyumov-Gerasimenko, also known as Comet 67P. The stereo anaglyph was created by combining two images […]

Messier 15 is a 13 billion year old relic of the early formative years of our galaxy, one of about 170 globular star clusters that still roam the halo of […]

Why are stars forming in the bridge between these colliding galaxies? Usually when galaxies crash, star formation is confined to galaxy disks or tidal tails. In Arp 194, though, there […]