Galileo image of Gaspra
(29 October 1991)
Click on image for full size
Asteroids are small bodies that are believed to be left over from the beginning of the solar system 4.6 billion years ago. They are rocky objects with round or irregular shapes up to several hundred km across, but most are much smaller.
More than 100,000 asteroids lie in a belt between Mars and Jupiter. These asteroids lie in a location in the solar system where there seems to be a jump in the spacing between the planets. Scientists think that this debris may be the remains of an early planet, which broke up early in the solar system. Several thousand of the largest asteroids in this belt have been given names.
The chances of an asteroid colliding with Earth are very small! But some do come close to Earth, like Hermes (closest approach of 777,000 km).
You might also be interested in:
On the night of July 19, 2009, Anthony Wesley noticed a dark splotch on Jupiter that hadn't been there before. Wesley, an amateur astronomer in Australia, had discovered the remnants of a huge impact on...more
A moon was discovered orbiting the asteroid, Eugenia. This is only the second time in history that a satellite has been seen circling an asteroid. A special mirror allowed scientists to find the moon...more
Scientists just created an asteroid map that shows over 900 asteroids that could someday collide with Earth. Any asteroid 1 kilometer long or larger is considered a danger. Even one of these smaller space...more
The first asteroid collection mission has been set. Japan and the United States will put joint efforts into the MUSES-C mission to be launched in January 2002 from Kagoshima Space Center, Japan. This will...more
Lutetia is a medium-sized asteroid which orbits in the main asteroid belt between the planets Mars and Jupiter. It is officially known as "21 Lutetia" because it was the 21st asteroid discovered. The asteroid...more
After a long, slow struggle, the Japanese space program is taking off! Japan's space program started as University researchers launching pencil-sized rockets in the 1950's. They struggled and fought against...more
A recent study shows there is a possibility that we came from Mars! No, that doesn't mean a spaceship flew here and dropped us off. Rather, scientists say chunks of rock were thrown off the Red Planet...more