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Meteorites |
Meteorites are mostly pieces of rock, though a few are metal, that fall to Earth from space. Most meteorites come from the break-up of small asteroids that never accreted to form a planet....but not all! Meteorites tell us the story of solar system history from the formation of the planets to catastrophic impacts on Earth.
Meteorite Sample Disk
NASA has prepared a Meteortie Sample Disk for loan to educators to help students learn about the early history of the solar system. The disk contains six labeled meteorites embedded in a 15-cm plastic disk. These pieces of asteroids represent the products of basic planetary processes: accretion, differentiation, volcanism, and impact cratering. The Meteorite Sample Disk package contains the disk, a copy of the activity guide called "Exploring Meteorite Mysteries," and a slide set.
To borrow the disk, educators must first attend a short certification briefing on secruity requirements and handling procedures. This is the same certification as for borrowing the Lunar Sample Disk. These briefings are given by NASA staff at locations around the country. After certification, educators may request a loan of the disks for periods of one to two weeks. Written requests should be sent to the NASA Educator Resource Center in your geographic area at least one month before the requested loan date. Spacelink has all the addresses and contact numbers for these Centers.
Spacelink also has the activity guide, NASA publication EG-1997-08-104-HQ, on-line at: Exploring Meteorite Mysteries.
To order the slide set separately, please contact CORE.
Why study meteorites?
| Meteorite | Percent silicates (rocky materials) | Percent metallic iron and iron sulfide | Characteristics and formation |
| Chondrites | 80 | 20 | These contain chondrules (round objects that were flash-heated before asteroids formed); once accreted, chondrites never melted. |
| Carbonaceous Chondrites | > 99 | < 1 | The most primitive meteorites, these contain water and carbon compounds including a variety of organic molecules. May contain diamond and amino acids. |
| Achondrites | > 99 | < 1 | These are igneous rocks formed from lavas that compose the crust of asteroids. Or they formed from the material remaining inside asteroids, e.g., from asteroid mantle material. |
| Iron meteorites | < 1 | > 99 | Most of these are solidified cores of asteroids that melted. |
| Pallasites | 50 | 50 | These are mostly the mineral olivine surrounded by metallic iron-nickel; formed at the boundary between an asteroid's core and mantle. |
The Planetary Materials Curation at Johnson Space Center has more information.
Hey, what's this?
This meteorite, collected on Earth, is an igneous rock containing trapped air exactly like the martian atmosphere! This sample and nine others, termed SNC (pronounced "snick") meteorites, are 1.3 billion years old or less, which is much too young for the source to be asteroids or the Moon. What do you think about that? An impact event probably blasted if off from a young volcanic region on Mars!
Find out about meteorites from Mars from the Johnson Space Center.