Transcript Early Solar System

Leonid Meteor Shower – every November
Murchison meteor
A carbonaceous
chondrite which
exploded into
fragments over the
town of Murchison,
approx. 200 km north
of Melbourne in
Victoria, Australia, on
Sep. 28, 1969. About
82 kg of the meteorite
was recovered.
Eyewitnesses arriving at the scene reported smelling
something like methanol or pyridine, an early indication
that the object might contain organic material.
Subsequent analysis by NASA scientists and a group led
by Cyril Ponnamperuma revealed the presence of 6
amino acids commonly found in protein and 12 that did
not occur in terrestrial life. All of these amino acids
appeared in both dextrorotatory (right-handed) and
laevorotatory (left-handed) forms, suggesting that they
were not the result of Earthly contamination. The
meteorite also contained hydrocarbons which appeared
abiogenic in character and was enriched with a heavy
isotope of carbon, confirming the extraterrestrial origin
of its organics. Initial studies suggested that the amino
acids in the Murchison meteorite showed no bias
between left- and right-handed forms.
However, in 1997, John R. Cronin and Sandra
Pizzarello of Arizona State University reported
finding excesses of left-handed versions of four
amino acids ranging from 7 to 9%,1 a result
confirmed independently by another group.2
More than 70 amino acids have been identified
in Murchison altogether. To this organic
mixture, in 2001, was added a range of polyols
– organic substances closely related to sugars
such as glucose.