PRIMITIVE VISITOR FROM SPACE ARRIVES IN UK
Scientists from the Natural History Museum (NHM) in London, working with colleagues from the Open University (OU) in Milton Keynes, have been examining an intriguing arrival from outer space.
The Tagish Lake meteorite, which fell in the Yukon region of northern Canada on the morning of 18 January 2000, contains some of the most primitive material ever to have landed on the Earth. Samples from this rare visitor are rich in carbon, nitrogen, hydrogen and sulphur, confirming that it is an extremely unusual meteorite, closely related to comets.
Dr. Monica Grady of the Natural History Museum in London will be unveiling some of the secrets of this ancient piece of Solar System history in a talk at the UK National Astronomy Meeting in Cambridge on Wednesday 4 April.
FROM FROZEN LAKE TO UNIVERSITY LAB
The Tagish Lake meteorite made quite a spectacle when it arrived on Earth. As it entered the atmosphere, it created a bright fireball, accompanied by a prominent dust tail. The following day, approximately 2 kg of meteorite was recovered from the frozen surface of Tagish Lake. The material remained frozen during subsequent transport and storage at the NASA-Johnson Space Centre curatorial facility in Houston, Texas.
A tiny piece of the meteorite (just less than 10mg, about the weight of a grain of rice) was flown to the Natural History Museum in London, then, after a preliminary optical examination, it was taken to the Open University (OU) in Milton Keynes.
Using the specialised equipment only available at the OU, Dr. Grady was able to determine that Tagish Lake contained more carbon and nitrogen than any other meteorite. The carbon was present mostly as organic compounds - the building blocks of life.
Tagish Lake was also found to be extremely rich in interstellar diamond grains, showing that it formed in the outermost reaches of the pre-solar nebula.
"This exciting and unusual meteorite will give us new insights into many areas of research, including comets, asteroids, the formation of the Solar System and the origin of life," said Dr. Grady.
Monica Grady is Curator of Meteorites at the Natural History Museum in London, where she undertakes research on primitive meteorites, Martian material and cosmic dust, using the Museum's state-of-the-art analytical instrumentation.
The Natural History Museum houses the UK's national meteorite collection, one of the finest collections in the world. Highlights from the collection are on permanent display in the Meteorite Pavilion, which was recently refurbished with the assistance of funding from PPARC's Public Understanding of Science programme.
The Open University is home to the Planetary and Space Sciences Research Institute (PSSRI), one of Europe's largest planetary research groups. Custom-designed equipment is used to measure the light element geochemistry of extraterrestrial materials, using samples too small to be measured elsewhere.
FOR INFORMATION ABOUT TAGISH LAKE:
Dr. Monica M. Grady, Mineralogy Dept., Natural History Museum Cromwell Road, London SW7 5BD
Issued by: RAS Press Officers Peter Bond
Dr Jacqueline Mitton