Sunspots: Magnetic Depressions
13.01.1997

Our Sun has spots! These spots appear dark in photographs like the one above, but in fact sunspots are quite bright - they are just dark compared to the rest of the Sun. Sunspots are about the size of the Earth and frequently occur in groups, as shown above.

Lunar Orbiter Earthset
27.08.2016

August 10th was the 50th anniversary of the launch of Lunar Orbiter 1. It was the first of five Lunar Orbiters intended to photograph the Moon's surface to aid in the selection of future landing sites.

Phobos Over Mars
15.10.1996

Hurtling through space a mere 3,000 miles above the Martian surface, the diminutive moon Phobos (below and left of center) was imaged against the backdrop of a large shield volcano by the Viking 2 Orbiter in 1977.

A Partial Eclipse in Southern Skies
3.09.1997

Location is everything, especially if you want to see a Solar Eclipse. These fleeting events are only visible to those in the path of the Moon's shadow as it races across the Earth.

Phoebe: Comet Moon of Saturn
30.06.2004

Was Saturn's moon Phoebe once a comet? Images from the robotic Cassini spacecraft taken two weeks ago when entering the neighborhood of Saturn indicate that Phoebe may have originated in the outer Solar System.

Saturns Moon Rhea from Cassini
15.02.2005

Each moon of Saturn seems to come with its own mystery. Rhea, Saturn's second largest moon behind Titan, shows unusual wisps, visible above as light colored streaks. Higher resolution images of the wisps show them to be made of long braided fractures.

Follow The Spots
21.10.1999

The Sun rotates on its axis about once every 27 days. How can you tell? Just follow the sunspots. This composite picture was constructed from solar images recorded daily by the MDI instrument on board the space-based SOlar and Heliospheric Observatory (SOHO).

Io in True Color
20.09.1999

The strangest moon in the Solar System is bright yellow. This recently released picture, showing Io's true colors, was taken in July by the Galileo spacecraft currently orbiting Jupiter. Io's colors derive from sulfur and molten silicate rock. The unusual surface of Io is kept very young by its system of active volcanoes.

Crater on Mimas
8.03.2005

Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn's smallest moons. The crater, named Herschel after the 1789 discoverer of Mimas, Sir William Herschel, spans about 130 kilometers and is pictured above in the dramatic light of its terminator.

Mercury: A Cratered Inferno
19.08.2001

Mercury's surface looks similar to our Moon's. Each is heavily cratered and made of rock. Mercury's diameter is about 4800 km, while the Moon's is slightly less at about 3500 km (compared with about 12,700 km for the Earth). But Mercury is unique in many ways.