Callisto in True Color
11.05.1998

Callisto's surface has many stories to tell. The most distant of Jupiter's Galilean Moons, Callisto shows the highest density of impact craters in the Solar System, but harbors no volcanoes or even any large mountains. Callisto's surface is laced with cracks and craters from

Sun Dance
11.08.1998

Hot gas dances across the surface of the Sun in this picture from the orbiting TRACE satellite. The temperature of the gas is color coded so that blue represents hundreds of thousands of Kelvin, while red represents extreme temperatures in the millions of Kelvin.

Neptune's Moon Proteus
3.11.1995

Proteus is the second largest moon of Neptune behind the mysterious Triton. Proteus was discovered only in 1982 by the Voyager 2 spacecraft. This is unusual since Neptune has a smaller moon - Nereid - which was discovered 33 years earlier from Earth.

Skylab Over Earth
10.05.1998

Skylab was an orbiting laboratory launched by a Saturn V rocket in May 1973. Skylab was visited three times by NASA astronauts who sometimes stayed as long as two and a half months. Many scientific tests were performed on Skylab, including astronomical observations in ultraviolet and X-ray light.

The Mountains of Mars
19.07.1995

Volcanic activity on Mars has produced towering mountains. The largest one, Olympus Mons, is pictured here in this Viking Orbiter image. Olympus Mons is a shield volcano nearly 15 miles high and over 300 miles wide at its base.

Skylab Over Earth
29.04.2006

Skylab was an orbiting laboratory launched by a in May 1973. Skylab, pictured above, was visited three times by NASA astronauts who sometimes stayed as long as two and a half months. Many scientific tests were performed on Skylab, including astronomical observations in ultraviolet and X-ray light.

Welcome Home Shannon Lucid
27.09.1996

Today is Shannon Lucid's first day on Planet Earth in six months. Her stay aboard Russia's Mir Space Station was of record length - the longest stay of any American in space ever.

Arachnoids on Venus
19.01.1998

Arachnoids are large structures of unknown origin that have been found only on the surface of Venus. Arachnoids get their name from their resemblance to spider-webs. They appear as concentric ovals surrounded by a complex network of fractures, and can span 200 kilometers.

Skylab Over Earth
28.05.2000

Skylab was an orbiting laboratory launched by a Saturn V rocket in May 1973. Skylab was visited three times by NASA astronauts who sometimes stayed as long as two and a half months. Many scientific tests were performed on Skylab, including astronomical observations in ultraviolet and X-ray light.

Radioactive Clouds in the Milky Way
28.10.1995

When massive stars explode they create large radioactive blast clouds which expand into interstellar space. As the radioactive elements decay, they produce gamma-rays. Possible locations of these stellar explosions known as supernovae, are indicated by the bright clumps in this map of the central regions of our Milky Way Galaxy.