The Tagish Lake meteorite appears to be the most primitive sample of the solar system on Earth and may become the new chemical standard against which celestial bodies are measured, reports an international team of scientists in today's issue of the journal Science . This is clearly a meteorite that doesn't fit any of our previous classifications. Orgueil is the touchstone against which they compare the composition of the Earth, the moon and other celestial bodies. Clayton contributed the oxygen isotopic measurement to the Science study, a key piece of data in revealing the meteorite's unusual composition. The Science study was led by the University of Western Ontario's Peter G. Brown.
Isotopes are the siblings of the elemental world.
They are atoms of an element that have different numbers of neutrons, and hence they have slightly different chemical properties. Oxygen has three isotopes, which Clayton uses to trace meteorites to their points of origin. Broadly speaking, the Tagish Lake meteorite is a carbonaceous chondrite. This type of meteorite has changed little since the birth of the solar system approximately 4.5 billion years ago. These rocks resemble charcoal but are actually the crown jewels of meteorite research.