[UFOpals] Fireball ignites scientific
Date: 10/14/00 10:17:15 AM Pacific Daylight Time
From BBC Online:
Fireball ignites scientific curiosity
BBC News Online science editor Dr David Whitehouse
Scientists have revealed new data about a meteorite that could be one of the
most primitive Solar System objects yet studied.
The space rock was recovered from the frozen Tagish Lake in Canada. The
meteorite has aroused huge excitement among researchers because its fragments
could help us understand better how the planets were formed.
The rock fell to Earth on 18 January, 2000. The exceptionally long and bright
fireball was seen throughout the Yukon, Northern British Columbia, parts of
Alaska, and the Northwest Territories.
Several dozen pieces of it have been retrieved. Importantly, the pieces were
picked up still frozen, providing researchers with a unique opportunity to
study organic compounds that may even have been the building blocks of life
The Tagish Lake meteorite is a so-called carbonaceous chondrite, a rare type
of ancient meteorite that makes up only 2% of all meteorite finds. Unlike
most rock found in the Solar System, it has not been changed by major heating
sometime in its history and as such allows researchers a chance to study the
very stuff that came together to form the Sun and the planets.
Analysis of the Tagish Lake meteorite, reported in the journal Science by
Peter G Brown at the University of Western Ontario, Canada, and colleagues,
suggests the rock may represent a completely new class of carbonaceous
chondrite, more primitive than any yet found.
Using eyewitness accounts, photographs, videos, and satellite data of the
rock's fiery and dramatic entrance into the Earth's atmosphere, the
researchers have also calculated where the meteorite came from.
Its trajectory indicates that the space rock originated from the middle of
the asteroid belt which lies between the orbits of Mars and Jupiter (about
300 million to 600 million kilometres/186 million to 370 million miles from
Analysis of the carbon in Tagish Lake indicates that some of it is in the
form of so-called nanodiamonds, tiny particles of interstellar material that
were in the solar nebula, the cloud of gas and dust that came together to
form the Solar System. Tagish Lake may be richer in interstellar grains than
any meteorite studied before.
Jeffrey Grossmann of the US Geological Survey says that Tagish Lake is the
most significant meteorite to come into the hands of scientists since the
well-known Allende meteorite from Mexico and the Murchison meteorite from
Australia, both of which were picked up in 1969.
Alan Hildebrand of the University of Calgary, Canada, says that the best
indication of the significance of the Tagish Lake recovery can be seen in the
receipt of dozens of requests from meteorite researchers around the world to
study the new rock.
One fragment is already in the hands of British researchers at the Natural
History Museum in London.
One very interesting aspect of the Tagish Lake study is the compilation of
detailed eyewitness accounts of the fireball.
Many people noticed smells at the time of the rock fall. These were
frequently described as sulphurous, although hot metal and rock were also
mentioned. And these smells were picked up by people many tens of kilometres
from the drop zone.
About one in 10 also reported sound instantaneous to the fireball event. It
might seem impossible that a noise can be heard concurrent with an object
moving at speed many kilometres away, but scientists now believe this to be
what they term an electrophonic effect.
It is possible that the twisting wake of a fireball might trap a magnetic
field, creating very long radio waves that travel to the ground at the speed
of light. The waves then interact with almost any object to produce a sound
audible to the skywatcher.