Rocks from Space!

Image

A number of years ago, during a visit to Texas Christian University, I visited the Oscar Monnig meteorite collection.

http://www.monnigmuseum.tcu.edu/Home.html

Before this visit, I knew what meteorites were (rocks from space that actually make it to the Earth’s surface), but I had never given much thought to where they came from (other than the famous Mars meteorite).

Scientists, of course, had thought about it and have figured out the “parent” source of some meteorites.

A few meteorites have been caught on camera as they heat up falling through the Earth’s atmosphere, and their previous orbits can be determined from that data.  The results show that most meteorites came from the asteroid belt.

An early example is here:

http://hyperion2.cc.uregina.ca/%7Eastro/Peek_1.pdf

Some clever scientists set up their cameras where it would be easy to find any meteorites that made it to the Earth.

http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_18-9-2009-11-20-41?newsid=73461

Radar data can also be used to find meteorites and figure out where they came from.

http://cams.seti.org/Science-Manuscript-SM.pdf

But meteorites that are caught on camera during reentry are rare.

Scientists can also measure the reflection spectra of meteorites (the amount of light reflected back at various frequencies) and compare them to the telescopic spectra of various asteroids.  They found some pretty close matches:

http://www.mtholyoke.edu/~tburbine/Burbine.asteroidsIII.20002.pdf

But not all meteorites come from asteroids.  Some come from planets.

Martian meteorites tend to be “young” and contain gases that match the Martian atmosphere measured by the Viking spacecraft.

http://curator.jsc.nasa.gov/antmet/mmc/Chap%20I.pdf

Lunar meteorites are also identified by their mineralogy and chemistry.

http://meteorites.wustl.edu/lunar/howdoweknow.htm

Recently, a meteorite was found in Africa that might originally be from Mercury:

http://www.skyandtelescope.com/news/home/The-First-Ever-Meteorite-from-Mercury-189374981.html

How cool is that?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s