Center for Meteorite Studies

 
Where do meteorites come from?
Most meteorites are believed to originate in the asteroid belt between Mars and Jupiter, and wereasteroid breakup formed early in the history of the Solar System ~4.56 billion years ago.  These fragments of asteroids were either knocked out of their orbit of the Sun, and into Earth-crossing orbits, through collisions with other objects, or through the interaction of gravitational forces exerted by the Sun and Jupiter.  
Image credit: NASA/JPL-Caltech
 
How do we know meteorites come from space?
Meteorites that come from the asteroid belt are about the same age as the solar system, approximately 4.5 billion years old. No Earth rocks are this old, because they have all been repeatedly broken down and reformed by terrestrial geological processes such as erosion and plate tectonics.
 
Which asteroids do they come from?
Vesta fullWhile it is difficult to pinpoint specific asteroids as parent bodies of specific meteorite types, comparison of meteorite data with data from asteroids from Earth-based observations and spacecraft can help to define likely sources of some meteorite types.  For example, data collected by NASA’s Dawn spacecraft has strengthened the theory that the HED (Howardites, Eucrites and Diogenites) group of achondrites formed in the crust of asteroid 4-Vesta (This mosaic synthesizes some of the best views the Dawn spacecraft had of the giant asteroid Vesta. Image credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA).

Meteorites from a tracked asteroid

The small asteroid 2008 TC3 was first discovered October 6th, 2008, by an automated telescope at Mount Lemmon in Tucson, Arizona.  The asteroid was tracked closely as it entered Earth's atmosphere and exploded approximately 37 km above northern Sudan’s Nubian Desert early the following morning.

The meteorites recovered from this fall, named Almahata Sitta, are extremely interesting, as the specimens exhibit multiple distinct lithologies, ranging from ordinary chondrite to bencubinnite. The stones from this unprecedented event continue to provide key information about the composition of asteroids.

Do we have meteorites from other planets?
Some meteorites come from the Moon and Mars.  These lunar or martian crustal rocks were ejected into space when another (asteroidal or cometary) object collided with the Moon or Mars with enough force to launch some of the impact-produced debris into Earth-crossing orbits.
 
How do we know they’re from Mars?w-Nakhla
Martian meteorites are distinguished from Earth rocks and other meteorite types by their chemical and mineral composition, as well as their age.  Moreover, gases trapped in shock glass in martian meteorites have been matched to measurements of the martian atmosphere taken by the NASA Viking mission in 1976.
 
Nakhla, martian achondrite.  Image ⓒ ASU/CMS
 
How do we know they’re from the Moon?
Because we’ve been there!  Lunar meteorites are identified by their unique chemical and mineral characteristics indicative of their origin on the Moon, mainly based on comparison to lunar rocks returned to Earth by the Apollo and Luna missions.
 
Did you know that the first ever carbon analysis of lunar rocks was done at the ASU Center for Meteorite Studies?  Learn more about it here!
 
 
Do we have any confirmed meteorites from Venus or Mercury?Venus
Not yet, but there could be pieces of both planets in existing meteorite collections, waiting to be identified. Data from NASA’s MESSENGER mission could help to identify potential mercurian meteorites, while venusian meteorites might be distinguished using data from the Vega 1 and 2 landers, and the Magellan spacecraft.
Venus. Image credit: SSV, MIPL, Magellan Team, NASA
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Comments are closed.

Facebook
Twitter
YouTube

Sign Up for Center Updates!

Be the first to learn about CMS events and news; sign up for email updates here!


Postdoctoral Scholar Opportunities!

The Center for Meteorite Studies at Arizona State University invites applications for 2 Postdoctoral Research Associates.  Click here for details!




Meteorite of the Month

Benguerir

November’s meteorite of the month is Benguerir, an (LL6) ordinary chondrite that fell in Morocco in 2004. According to the Meteoritical Bulletin (MB 89): A meteorite shower was witnessed to …


Upcoming Events

November 2017
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
October 29, 2017 October 30, 2017 October 31, 2017 November 1, 2017 November 2, 2017 November 3, 2017 November 4, 2017
November 5, 2017 November 6, 2017 November 7, 2017 November 8, 2017 November 9, 2017 November 10, 2017 November 11, 2017
November 12, 2017 November 13, 2017 November 14, 2017 November 15, 2017 November 16, 2017 November 17, 2017 November 18, 2017

Earth and Space Exploration Day

Earth and Space Exploration Day
November 19, 2017 November 20, 2017 November 21, 2017 November 22, 2017 November 23, 2017 November 24, 2017 November 25, 2017
November 26, 2017 November 27, 2017 November 28, 2017 November 29, 2017 November 30, 2017 December 1, 2017 December 2, 2017