Asteroids

An asteroid

Vesta is one of the largest asteroids in the solar system

Principal Investigator

Prof Sara Russell

Project summary

We are studying chondrite meteorites in our collection to learn about 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

Our current research focuses on dating chondrite meteorites and studying their chemical and mineral composition.

We are isolating chondrules from primitive chondrite meteorites and calculating how much Aluminium-26 (26Al) they originally contained by measuring the daughter isotope Magnesium-26 (26Mg). Radioactive 26Al has a half-life of 0.73 million years. Measuring the 26Mg content allows us to date these meteorites.

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
  • isotope composition of oxygen.

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

CI chondrites are the most chemically primitive objects we have access to. Their composition is similar to that of the Sun. We are studying the mineralogy of CI chondrites and measuring their chemical make-up and water content.

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

Sulphide minerals are found in many meteorites. We are investigating the trace element composition of these minerals 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 microprobes.

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

We use X-ray diffraction as a complementary technique to study the mineralogy of meteorites.

Museum staff

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

Collaborators

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 one millimetre in diameter.

Half-life

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

Related information

Meteorites group blog

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