Galaxies might not have such discreet boundaries as we imagined. Instead, they might stretch out to great distances, forming a vast, interconnected sea of stars.
It looks like an artist's illustration, but it's a real image and it lets us glimpse the process by which planets are born in orbit around their stars.
Researchers used an ultra-high-speed cannon to simulate a collision on Vesta. Images taken at a million frames per second show how Vesta got its grooves.
Here's a newly released color mosaic of Titan - taken in near-infrared part of the spectrum - showing the sun glinting off of Titan's north polar seas. Beautiful!