Nebula IC 63 - in the direction of our constellation Cassiopeia - is slowly dissipating under the influence of ionizing ultraviolet radiation from a hot, luminous variable star known as Gamma Cas.

A rainbow glows over Kranzhorn Mountain in Germany's Bavarian Alps.

These images from the Mars Express spacecraft show an ancient, dried-up river system, one of the longest valley networks on Mars.

Watch 2 NASA astronauts aboard the International Space Station (ISS) make history by performing the 1st ever all-female spacewalk on Friday.

Exoplanets - worlds orbiting distant suns - are very, very far away. Astronomers are learning what some might look like, and what's in their atmospheres. Soon - for the first time - a new telescope will be able to "see inside" some exoplanets.

New research suggests that the tiny human species - that survived until about 18,000 years ago, later than any human species other than our own - evolved its small size remarkably quickly while living on an isolated island.

Lenticular cloud over Butte, Montana.

Glaciers are melting in many places on Earth today. But glacier loss in the Peruvian Andes is happening particularly rapidly. New research reports a reduction of almost 30% between 2000 and 2016.

Northern and Southern Hemisphere views of Venus from October 2019 to June 2020, and some insights on the coming view of Venus in the evening sky.

As it orbits Earth once a month, the moon is up during the day half the time, pale against the blue sky. You can see it this weekend, if you look.