Martian Moon Phobos from Mars Express
8.11.2020

Why is Phobos so dark? Phobos, the largest and innermost of two Martian moons, is the darkest moon in the entire Solar System. Its unusual orbit and color indicate that it may be a captured asteroid composed of a mixture of ice and dark rock.

A Robots Shadow on Asteroid Itokawa
16.11.2005

What's that unusual looking spot on asteroid Itokawa? It's the shadow of the robot spacecraft Hayabusa that took the image. Japan's Hayabusa mission arrived at the asteroid in early September and has been imaging and maneuvering around the floating space mountain ever since. The above picture was taken earlier this month.

Cassini Approaches Saturn
15.03.2011

What would it look like to approach Saturn in a spaceship? One doesn't have to just imagine -- the Cassini spacecraft did just this in 2004, recording thousands of images along the way, and thousands more since entering orbit.

Super Planet Crash
11.01.2015

Can you create a planetary system that lasts for 500 years? Super Planet Crash, the featured game, allows you to try. To create up to ten planets, just click anywhere near the central star.

Circular Sun Halo
14.10.2023

Want to see a ring around the Sun? It's easy to do in daytime skies around the world. Created by randomly oriented ice crystals in thin high cirrus clouds, circular 22 degree halos are visible much more often than rainbows.

APOD: 2024 August 6 Б Storm Cloud Over Texas
6.08.2024

What makes this storm cloud so colorful? First, the cloud itself is composed of millions of tiny droplets of water and ice. Its bottom is almost completely flat -- but this isn't unusual. Bottom...

Light Deposits Indicate Water Flowing on Mars
12.12.2006

What's creating light-toned deposits on Mars? Quite possibly -- water! Images of the same parts of mid-latitude Mars taken over the years but released only last week have shown unexpected new light-toned deposits where there were none before.

Halo from Atacama
18.05.2016

Influenced by the strong Pacific El Nino, cloudy skies have more often come to Chile's high Atacama Desert this season, despite its reputation as an astronomer's paradise. Located...

Orionids Meteor Shower to Peak Tonight
21.10.1996

Tonight you might be able to see Halley's Comet again - or at least some pieces of it. It is widely thought that that the meteors from the Orionids meteor shower, which peaks tonight, are just small pieces of Halley's Comet falling to Earth.

Mars Weather Watch
16.08.1999

Mars may be a cold, dry planet but its weather is dynamic. On June 30, wide angle cameras on board the Mars Global Surveyor (MGS) spacecraft watched the development of this large scale storm system above Mars' north polar area.