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.
BACKGROUND INFORMATION
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.
CONTACTS:
FOR INFORMATION ABOUT TAGISH LAKE:
Dr. Monica M. Grady
Mineralogy Dept.
Natural History Museum
Cromwell Road
London
SW7 5BD
Phone: +44 (0)20-7942-5709
E-mail: m.grady@nhm.ac.uk
FOR INFORMATION ABOUT THE PSSRI:
Dr. Ian Wright
Planetary and Space Sciences Research Institute
The Open University
Milton Keynes
MK7 6AA
Phone: +44 (0)1908-653898
E-mail: i.p.wright@open.ac.uk
IMAGES AND FURTHER INFORMATION CAN BE FOUND ON THE WEB AT:
http://www.nhm.ac.uk
http://www.nhm.ac.uk/mineralogy/research/meteor.htm
http://www.nhm.ac.uk/mineralogy/grady/grady.htm
http://www.astro.uwo.ca/~pwbrown/tagish/
