Mercury: A Cratered Inferno
12.09.1996

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.

Eclipsed Moon and Stars
23.05.2003

Half-shadowed by the Earth, the Moon takes on a remarkable appearance against a field of stars in this intriguing telephoto picture recorded during a partial phase of last week's lunar eclipse. The picture is not a composite, but it has been digitally enhanced to bring out features covering a large range in brightness.

Sol 5 Postcard from Mars
9.01.2004

A martian Sol - the average martian solar day - is about 39 minutes longer than Earth's familiar 24 hour day. Operating on martian time, the Spirit rover recently sent back this color postcard image, recorded on Sol 5 of its stay on the martian surface.

Earth's North Magnetic Pole
19.10.1999

A magnetic compass does not point toward the true North Pole of the Earth. Rather, it more closely points toward the North Magnetic Pole of the Earth. The North Magnetic Pole is currently located in northern Canada.

Mimas: Small Moon with a Big Crater
17.05.2009

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.

Lunar Dust and Duct Tape
28.03.2025

Why is the Moon so dusty? On Earth, rocks are weathered by wind and water, creating soil and sand. On the Moon, eons of constant micrometeorite bombardment have blasted away at the rocky surface creating a layer of powdery lunar soil or regolith.

Mercury: A Cratered Inferno
30.11.1997

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.

Lunar Dust and Duct Tape
10.11.2001

Why is the Moon dusty? On Earth, rocks are weathered by wind and water, creating soil and sand. On the Moon, the long history of micrometeorite bombardment has blasted away at the rocky surface creating a layer of powdery lunar soil or regolith. This lunar regolith could be a scientific and industrial bonanza.

A Giant Starspot on HD 12545
2.11.2003

What could cause a star to have such a large spot? Our Sun itself frequently has sunspots, relatively cool dark magnetic depressions that move across its surface. HD 12545, however, exhibits the largest starspots yet observed.

Europa: Ice Line
18.04.2000

This bright white swath cutting across the surface of icy Jovian moon Europa is known as Agenor Linea. In all about 1000 kilometers long and 5 kilometers wide, only a section is pictured here as part of a combined color and black and white image based on data from the Galileo spacecraft.