Reverend Dave
2009-08-20 02:30:51 UTC
http://www.reuters.com/article/scienceNews/idUSTRE57H02I20090818
Tue Aug 18, 2009 9:37am EDT
By Steve Gorman
LOS ANGELES (Reuters) - The amino acid glycine, a fundamental building
block of proteins, has been found in a comet for the first time,
bolstering the theory that raw ingredients of life arrived on Earth from
outer space, scientists said on Monday.
Microscopic traces of glycine were discovered in a sample of particles
retrieved from the tail of comet Wild 2 by the NASA spacecraft Stardust
deep in the solar system some 242 million miles (390 million km) from
Earth, in January 2004.
Samples of gas and dust collected on a small dish lined with a super-
fluffy material called aerogel were returned to Earth two years later in
a canister that detached from the spacecraft and landed by parachute in
the Utah desert.
Comets like Wild 2, named for astronomer Paul Wild (pronounced Vild), are
believed to contain well-preserved grains of material dating from the
dawn of the solar system billions of years ago, and thus clues to the
formation of the sun and planets.
The initial detection of glycine, the most common of 20 amino acids in
proteins on Earth, was reported last year, but it took time for
scientists to confirm that the compound in question was extraterrestrial
in origin.
"We couldn't be sure it wasn't from the manufacturing or the handling of
the spacecraft," said astrobiologist Jamie Elsila of NASA's Goddard Space
Flight Center in Greenbelt, Maryland, the principal author of the latest
research.
She presented the findings, accepted for publication in the journal
Meteoritics and Planetary Science, to a meeting of the American Chemical
Society in Washington, D.C., this week.
"We've seen amino acids in meteorites before, but this is the first time
it's been detected in a comet," she said.
Chains of amino acids are strung together to form protein molecules in
everything from hair to the enzymes that regulate chemical reactions
inside living organisms. But scientists have long puzzled over whether
these complex organic compounds originated on Earth or in space.
The latest findings add credence to the notion that extraterrestrial
objects such as meteorites and comets may have seeded ancient Earth, and
other planets, with the raw materials of life that formed elsewhere in
the cosmos.
"The discovery of glycine in a comet supports the idea that the
fundamental building blocks of life are prevalent in space, and
strengthens the argument that life in the universe may be common rather
than rare," said Carl Pilcher, the director of the NASA Astrobiology
Institute in California, which co-funded the research.
Glycine and other amino acids have been found in a number of meteorites
before, most notably one that landed near the town of Murchison,
Australia in 1969, Elsila said.
Tue Aug 18, 2009 9:37am EDT
By Steve Gorman
LOS ANGELES (Reuters) - The amino acid glycine, a fundamental building
block of proteins, has been found in a comet for the first time,
bolstering the theory that raw ingredients of life arrived on Earth from
outer space, scientists said on Monday.
Microscopic traces of glycine were discovered in a sample of particles
retrieved from the tail of comet Wild 2 by the NASA spacecraft Stardust
deep in the solar system some 242 million miles (390 million km) from
Earth, in January 2004.
Samples of gas and dust collected on a small dish lined with a super-
fluffy material called aerogel were returned to Earth two years later in
a canister that detached from the spacecraft and landed by parachute in
the Utah desert.
Comets like Wild 2, named for astronomer Paul Wild (pronounced Vild), are
believed to contain well-preserved grains of material dating from the
dawn of the solar system billions of years ago, and thus clues to the
formation of the sun and planets.
The initial detection of glycine, the most common of 20 amino acids in
proteins on Earth, was reported last year, but it took time for
scientists to confirm that the compound in question was extraterrestrial
in origin.
"We couldn't be sure it wasn't from the manufacturing or the handling of
the spacecraft," said astrobiologist Jamie Elsila of NASA's Goddard Space
Flight Center in Greenbelt, Maryland, the principal author of the latest
research.
She presented the findings, accepted for publication in the journal
Meteoritics and Planetary Science, to a meeting of the American Chemical
Society in Washington, D.C., this week.
"We've seen amino acids in meteorites before, but this is the first time
it's been detected in a comet," she said.
Chains of amino acids are strung together to form protein molecules in
everything from hair to the enzymes that regulate chemical reactions
inside living organisms. But scientists have long puzzled over whether
these complex organic compounds originated on Earth or in space.
The latest findings add credence to the notion that extraterrestrial
objects such as meteorites and comets may have seeded ancient Earth, and
other planets, with the raw materials of life that formed elsewhere in
the cosmos.
"The discovery of glycine in a comet supports the idea that the
fundamental building blocks of life are prevalent in space, and
strengthens the argument that life in the universe may be common rather
than rare," said Carl Pilcher, the director of the NASA Astrobiology
Institute in California, which co-funded the research.
Glycine and other amino acids have been found in a number of meteorites
before, most notably one that landed near the town of Murchison,
Australia in 1969, Elsila said.
--
Ignorance more frequently begets confidence than does knowledge: it is
those who know little, not those who know much, who so positively assert
that this or that problem will never be solved by science. - Charles
Darwin
Ignorance more frequently begets confidence than does knowledge: it is
those who know little, not those who know much, who so positively assert
that this or that problem will never be solved by science. - Charles
Darwin