Dog-Bone Shaped Asteroid 216 Kleopatra
10.05.2000

An asteroid the size of New Jersey that orbits the Sun between Mars and Jupiter has been discovered to have an unusual dog-bone shape. Asteroid 216 Kleopatra, recently mapped with Earth-based radar, reflects radio waves so well that astronomers speculate it is composed mostly of metals such as nickel and iron.

The Colorful Moon
7.01.1998

Do you recognize the Earth's Moon when you see it? The crazy, patchwork appearance of this false color image makes this nearly full view of our Moon's familiar nearside look very strange. The image was taken in 1992 by the Galileo spacecraft enroute to Jupiter.

Blue Sun Glaring
6.01.1997

The Sun is a bubbling ball of extremely hot gas. In this false-color picture, light blue regions are extremely hot - over 1 million degrees, while dark blue regions are slightly cooler. The camera filter used was highly sensitive to the emission of highly charged iron ions, which trace the magnetic field of the Sun.

Galactic Supernova Remnant IC 443
21.07.1999

About 8000 years ago, a star in our Galaxy exploded. Ancient humans might have noticed the supernova as a temporary star, but modern humans can see the expanding shell of gas even today.

Southwest Mercury
13.02.2000

The planet Mercury resembles a moon. Mercury's old surface is heavily cratered like many moons. Mercury is larger than most moons but smaller than Jupiter's moon Ganymede and Saturn's moon Titan. Mercury is much denser and more massive than any moon, though, because it is made mostly of iron.

The Colorful Moon
16.03.2002

Do you recognize the Earth's Moon when you see it? The crazy, patchwork appearance of the false-color image makes this almost full view of the Moon's familiar near side look very strange.

APOD: 2024 December 3 Б Ice Clouds over a Red Planet
3.12.2024

If you could stand on Mars -- what might you see? You might look out over a vast orange landscape covered with rocks under a dusty orange sky, with a blue-tinted Sun setting over the horizon, and odd-shaped water clouds hovering high overhead.

The Earths Magnetic Field
25.11.2002

Why does the Earth have a magnetic field? The electrical conductivity of the molten plasma of the Earth's core should be able to damp the current magnetic field in only thousands of years. Yet our five billion year old Earth clearly causes magnets to point to (defined) north.

Block Island Meteorite on Mars
13.08.2009

What is this strange rock on Mars? Sitting on a smooth plane, the rock stands out for its isolation, odd shape, large size and unusual texture. The rock was discovered by the robotic Opportunity rover rolling across Mars late last month. Pictured above, Opportunity prepares to inspect the unusual rock.

Unusual Spheres on Mars
25.09.2012

Why are these strange little spheres on Mars? The robotic rover Opportunity chanced across these unusually shaped beads earlier this month while exploring a place named Kirkwood near the rim of Mars' Endeavor Crater.