Asteroids

Chondrite meteorites in our collection are revealing conditions in the early solar system and the processes that formed the planets. 

Most of the 2,000 meteorites in our collection originate from a belt of minor planets between Mars and Jupiter. These asteroids formed at the same time as our solar system, around 4.5 billion years ago.

Chondrites are stony meteorites that have not melted or been modified since their formation. They preserve information about conditions in the primitive solar system, when the Sun, planets and asteroids were forming. 

Current Research

Timescales

We are isolating chondrules in primitive chondrite meteorites and calculating how much 26Al they originally contained by measuring the daughter isotope 26Mg.

Radioactive 26Al has a half-life of 0.73 million years and decays away over time. Measuring the 26Mg content allows us to date these meteorites.

Chondrule from the Palmyra (L3) ordinary chondrite.

Microscopic image of a chondrule from the Palmyra (L3) ordinary chondrite.

Matrix

Chondrules are surrounded by a fine-grained matrix. This matrix is not as well characterised as the larger components of meteorites. 

We are investigating the origins of matrix material by studying its:

  • texture
  • mineralogy
  • geochemistry
  • oxygen isotope composition
Chondrule rims

We are investigating the relationship between the mineralogy of chondrule accretionary rims and chondrule matrix.

CI meteorites

CI meteorites are the most chemically primitive material we can access, with a composition similar to that of the Sun. We are studying the mineralogy of CI chondrites and measuring their chemical abundances and water content.

CAI isotopic compositions

We are comparing the oxygen isotopic composition of calcium and aluminium-rich inclusions (CAI) and their rims to determine whether they formed in the same reservoir.

Sulphides

Sulphide elements are found in many meteorites. We are investigating the trace element composition of these elements to learn more about their abundance and distribution in the early solar system.

Methods

We use a combination of imaging techniques to determine the abundance of major and minor elements in our samples, including:

  • scanning electron microscropy (SEM) 
  • analytical techniques such as electron microprobe

We also use techniques such as mass spectrometry to analyse trace element abundances and isotope variations within the samples. 

X-ray diffraction is used as a complementary technique to determine the mineralogy of meteorites.

Project staff

  • Prof Sara Russell
  • Dr Paul Schofield
  • Dr Ashley King
  • Dr Jenny Claydon
  • Mr Epifanio Vacarro (PhD student)
  • Marlene Giscard (PhD student)
Project collaborators

Meteorites group blog

  • The bits of dust that fill up Space: first look

    Museum scientists Ashley King and Anton Kearsley have co-authored an article published in Science on 14 August 2014 on the first laboratory analysis of interstellar dust grains.Have you ever wondered what exists beyond the solar system? Most people t...
    Fri, 15 Aug 2014 09:48:59

  • 150 years of the ancient Orgueil meteorite

    As well as keeping you informed about our research we're going to use this blog to let you know more about our meteorite collection, especially the ones that aren't currently out on display.  All of us in the meteorite group are off to Casablanc...
    Thu, 14 Aug 2014 09:26:13

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Glossary

Chondrite
Meteorites containing rounded millimetre to centimetre-sized silicate objects called chondrules, surrounded by a fine-grained matrix. Chondrites have remained unmelted since their formation 4.5 billion years ago.

CI Chondrites
A group of stony, carbonaceous meteorites with a composition similar to that of the Sun. Chemically, they are the most primitive material we can study.

Chondrules
Round grains found in chondrite meteorites, usually around 1 millimetre in diameter.

Half-life
The time taken for the radioactivity of a specified isotope to decrease to half its original value.