The sudden spike of X-rays released as much energy in 20 seconds as our sun does in nearly 10 days. Turns out it was a massive thermonuclear flash on a pulsar, the crushed remains of a star that exploded as a supernova long ago.

Wow! Check out these space-based views of the Mercury transit from NASA's Solar Dynamics Observatory.

NASA's Lunar Reconnaissance Orbiter has returned some amazing high-resolution photos of the surface of the moon, including these ones of steep cliffs and impact melt inside a young crater called Giordano Bruno.

You've heard of panspermia, the idea that life exists throughout space and was carried to Earth by comets? What if the reverse occurred, with microbes on Earth ejected into space by asteroid impacts, escaping into the solar system billions of years ago?

New images from ESO's Very Large Telescope show that asteroid Hygiea is round, meaning that it may now be classified as the smallest-known dwarf planet in our solar system.

TESS watched a black hole tear apart a star from start to finish, a cataclysmic phenomenon called a tidal disruption event.

... and it's poised to find thousands more. But will we find another Earth?

Mosaic of the southern sky constructed from 208 images by NASA’s TESS spacecraft, taken during the mission’s first year of science operations.

Contrary to previous thought, a giant planet in a wild orbit doesn't mean there can't be an Earth-like planet in the same system. What’s more, the view from that Earth-like world as its giant neighbor moves past would be unlike anything we've ever seen.

Voyager 2 left the realm of the sun's influence a year ago today, becoming the 2nd craft ever to do so. This week, the journal Nature Astronomy published 5 new papers describing what Voyager 2 has been seeing on its journey into the unknown.