From ESA's Proba-2 satellite, images of the sun in January or February of each year from 2010 to 2019. This mosaic neatly shows the variability in the solar atmosphere in beautiful detail.

The distant Kuiper Belt object formerly known as 2014 MU69 - later known as Ultima Thule - has been renamed again. Its new name is Arrokoth.

The distant galaxy in this image is nicknamed the Sunburst Arc. It's been lensed into multiple images by a massive, intervening galaxy cluster. A recent study revealed that the 4 bright arcs in this Hubble image contain 12 images - cosmic doppelgangers - of this very distant galaxy.

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?