The Earth and Moon Planetary System
15.10.2001

How similar in size are the Earth and the Moon? A dramatic visual answer to this question is found by combining photographs taken by the Mariner 10 spacecraft that headed out toward Venus and Mercury in 1973.

APOD: 2004 August 24- Supply Ship Approaches the Space Station
24.08.2004

The crew on board the International Space Station sometimes needs supplies. As the US Space Shuttle fleet prepares to return to flight, supplies usually now come from a robot Progress supply vessel launched from Kazakhstan.

Looking Out Over Mars
23.08.2004

What would it be like to climb a hill and look out over Mars? That opportunity was afforded the Spirit rover earlier this month as it rolled to a high perch in the Columbia Hills.

A Lenticular Cloud Over Wyoming
26.03.2003

Is that a cloud or a flying saucer? Both, although it is surely not an alien spacecraft. Lenticular clouds can be shaped like a saucer, and can fly in the sense that, like most clouds, they are composed of small water droplets that float on air.

Neptune: Big Blue Giant
21.02.1998

This picture was taken by the Voyager 2 spacecraft in 1989 - the only spacecraft ever to visit Neptune. Neptune will be the farthest planet from the Sun until 1999, when the elliptical orbit of Pluto will cause it to once again resume this status.

Rhea: Saturns Second Largest Moon
5.12.1999

Rhea is the second largest moon of Saturn, behind Titan, and the largest without an atmosphere. It is composed mostly of water ice, but has a small rocky core. Rhea's rotation and orbit are locked together (just like Earth's Moon) so that one side always faces Saturn.

A Seemingly Square Sun
26.05.1998

Isn't the Sun round? Yes, but in the above picture, the Earth's atmosphere makes it appear almost square. Here a layer of air near the Earth was so warm it acted like a giant lens, creating increasingly distorted paths for sunlight to reach the camera.

Neptune: Big Blue Giant
17.08.1995

This picture was taken by the Voyager 2 spacecraft in 1986 - the only spacecraft ever to visit Neptune. Neptune will be the farthest planet from the Sun until 1999, when the elliptical orbit of Pluto will cause it to once again resume this status.

Ganymede: Moonquake World
4.09.1995

Ganymede probably undergoes frequent ground shaking events not unlike terrestrial earthquakes. Ganymede, the largest moon of Jupiter and the Solar System, has a thick outer coating of water ice. Passing Voyager spacecraft found...

Saturn's Cleanest Moon: Enceladus
25.11.1995

Enceladus orbits Saturn between the smaller Mimas and the larger Tethys. Enceladus is composed mostly of water ice and has the cleanest and purest ice surface in the Solar System. It's surface therefore appears nearly white. The surface also has many unusual groves and relatively few craters, like Jupiter's moon Ganymede.