Mars Through a Small Telescope
19.08.2003

How does Mars appear through a small telescope? Viewed with the unaided eye or through a small telescope, possibly the most striking part of Mars' appearance is it's red color. The color derives from rust, iron oxide, which composes perhaps 10% of the Martian soil.

Atlas 5 Rocket Launches to the Moon
22.06.2009

This rocket is headed for the Moon. Pictured above, a huge Altas V rocket roared off the launch pad last week to start NASA's first missions to Earth's Moon in 10 years. The rocket is carrying two robotic spacecraft.

Europa: Ridges and Rafts on a Frozen Moon
10.09.1998

The large Jovian moon Europa may harbor liquid water beneath its frozen crust. Controversy surrounding this idea has been recently fueled by dramatic images of Europa's surface from the Galileo spacecraft. This alluring...

Martian Moon Phobos from Mars Express
1.12.2010

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.

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...