GALAXY'S DUST-CORE SMELLS LIKE RASPBERRIES, TASTES LIKE RUM
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Apr 28, 2009, 2:50:15 PM4/28/09
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NO SIGN OF ACTUAL SPACE RASPBERRIES
http://www.guardian.co.uk/science/2009/apr/21/space-raspberries-amino-acids-astrobiology
Galaxy's centre tastes of raspberries and smells of rum, say
astronomers
BY Ian Sample / 21 April 2009
Astronomers searching for the building blocks of life in a giant dust
cloud at the heart of the Milky Way have concluded that it tastes
vaguely of raspberries. The unanticipated discovery follows years of
work by astronomers who trained their 30m radio telescope on the
enormous ball of dust and gas in the hope of spotting complex
molecules that are vital for life. Finding amino acids in interstellar
space is a Holy Grail for astrobiologists, as this would raise the
possibility of life emerging on other planets after being seeded with
the molecules.
In the latest survey, astronomers sifted through thousands of signals
from Sagittarius B2, a vast dust cloud at the centre of our galaxy.
While they failed to find evidence for amino acids, they did find a
substance called ethyl formate, the chemical responsible for the
flavour of raspberries. "It does happen to give raspberries their
flavour, but there are many other molecules that are needed to make
space raspberries," Arnaud Belloche, an astronomer at the Max Planck
Institute for Radio Astronomy in Bonn, told the Guardian. Curiously,
ethyl formate has another distinguishing characteristic: it also
smells of rum.
The astronomers used the IRAM telescope in Spain to analyse
electromagnetic radiation emitted by a hot and dense region of
Sagittarius B2 that surrounds a newborn star. Radiation from the star
is absorbed by molecules floating around in the gas cloud, which is
then re-emitted at different energies depending on the type of
molecule. While scouring their data, the team also found evidence for
the lethal chemical propyl cyanide in the same cloud. The two
molecules are the largest yet discovered in deep space.
Dr Belloche and his colleague Robin Garrod at Cornell University in
New York have collected nearly 4,000 distinct signals from the cloud
but have only analysed around half of these. "So far we have
identified around 50 molecules in our survey, and two of those had not
been seen before," said Belloche. The results are being presented
today at the European Week of Astronomy and Space Science at the
University of Hertfordshire.
Last year, the team came tantalisingly close to finding amino acids in
space with the discovery of a molecule that can be used to make them,
called amino acetonitrile. The latest discoveries have boosted the
researchers' morale because the molecules are as large as the simplest
amino acid, glycine. Amino acids are the building blocks of proteins
and are widely seen as being critical for complex life to exist
anywhere in the universe. "I wouldn't be surprised if we find an amino
acid out there in the coming years," said Belloche.
Previously, astronomers have detected a variety of large molecules,
including alcohols, acids and chemicals called aldehydes. "The
difficulty in searching for complex molecules is that the best
astronomical sources contain so many different molecules that their
'fingerprints' overlap and are difficult to disentangle," Belloche
said. The molecules are thought to form when chemicals that already
exist on some dust grains, such as ethanol, link together to make more
complex chains. "There is no apparent limit to the size of molecules
that can be formed by this process, so there's good reason to expect
even more complex organic molecules to be there," said Garrod.
CONTACT
Arnaud Belloche
http://www.mpifr-bonn.mpg.de/english/ueberInstitut/instMitarbeiter/index.html
email : bell...@mpifr-bonn.mpg.de
ETHYL FORMATE
http://www.physorg.com/news159548933.html
Highly complex organic molecules detected in space / 4.21.2009
Scientists from the Max Planck Institute for Radio Astronomy (MPIfR)
in Bonn, Germany, Cornell University, USA, and the University of
Cologne, Germany, have detected two of the most complex molecules yet
discovered in interstellar space: ethyl formate and n-propyl cyanide.
Their computational models of interstellar chemistry also indicate
that even larger organic molecules may be present - including the so-
far elusive amino acids, which are essential for organic life. The
results will be presented at the European Week of Astronomy and Space
Science at the University of Hertfordshire on Tuesday 21st April.
The IRAM 30 metre telescope in Spain was used to detect emissions from
molecules in the star-forming region Sagittarius B2, close to the
centre of our galaxy. The two new molecules were detected in a hot,
dense cloud of gas known as the "Large Molecule Heimat", which
contains a luminous newly-formed star. Large organic molecules of many
different sorts have been detected in this cloud in the past,
including alcohols, aldehydes, and acids. The new molecules, ethyl
formate (C2H5OCHO) and n-propyl cyanide (C3H7CN), represent two
different classes of molecule - esters and alkyl cyanides - and they
are the most complex of their kind yet detected in interstellar space.
Atoms and molecules emit radiation at very specific frequencies, which
appear as characteristic "lines" in the electromagnetic spectrum of an
astronomical source. Recognizing the signature of a molecule in that
spectrum is rather like identifying a human fingerprint. "The
difficulty in searching for complex molecules is that the best
astronomical sources contain so many different molecules that their
"fingerprints" overlap, and are difficult to disentangle" says Arnaud
Belloche, scientist at the Max Planck Institute and first author of
the research paper. "Larger molecules are even more difficult to
identify because their ‘fingerprints’ are barely visible: their
radiation is distributed over many more lines that are much weaker"
adds Holger Müller, researcher at the University of Cologne. Out of
3700 spectral lines detected with the IRAM telescope, the team
identified 36 lines belonging to the two new molecules.
The researchers then used a computational model to understand the
chemical processes that allow these and other molecules to form in
space. Chemical reactions can take place as the result of collisions
between gaseous particles; but there are also small grains of dust
suspended in the interstellar gas, and these grains can be used as
landing sites for atoms to meet and react, producing molecules. As a
result, the grains build up thick layers of ice, composed mainly of
water, but also containing a number of basic organic molecules like
methanol, the simplest alcohol.
"But," says Robin Garrod, a researcher in astrochemistry at Cornell
University, "the really large molecules don't seem to build up this
way, atom by atom." Rather, the computational models suggest that the
more complex molecules form section by section, using pre-formed
building blocks that are provided by molecules, such as methanol, that
are already present on the dust grains. The computational models show
that these sections, or "functional groups", can add together
efficiently, building up a molecular "chain" in a series of short
steps. The two newly-discovered molecules seem to have been produced
in this way.
Garrod adds, "There is no apparent limit to the size of molecules that
can be formed by this process - so there's good reason to expect even
more complex organic molecules to be there, if we can detect them."
Senior MPIfR team member Karl Menten thinks that this will happen in
the near future: "What we are doing now is like searching for a needle
in a haystack. Future instruments like the Atacama Large Millimeter
Array will allow much more efficient studies to discover organic
interstellar molecules." These may even include amino acids, which are
required for the production of proteins, and are therefore essential
to life on Earth.
The simplest amino acid, glycine (NH2CH2COOH), has been searched for
in the past, but has as yet not been successfully detected. However,
the size and complexity of this molecule is matched by the two new
molecules discovered by the team.
PREVIOUSLY ON SPECTRE --- SPACE SMELLS LIKE
http://spectregroup.wordpress.com/2008/02/27/space-smells-like/
THE SMELL OF MOONDUST
http://spectregroup.wordpress.com/2006/02/28/the-smell-of-moondust/
http://www.guardian.co.uk/science/2009/apr/21/space-raspberries-amino-acids-astrobiology
Galaxy's centre tastes of raspberries and smells of rum, say
astronomers
BY Ian Sample / 21 April 2009
Astronomers searching for the building blocks of life in a giant dust
cloud at the heart of the Milky Way have concluded that it tastes
vaguely of raspberries. The unanticipated discovery follows years of
work by astronomers who trained their 30m radio telescope on the
enormous ball of dust and gas in the hope of spotting complex
molecules that are vital for life. Finding amino acids in interstellar
space is a Holy Grail for astrobiologists, as this would raise the
possibility of life emerging on other planets after being seeded with
the molecules.
In the latest survey, astronomers sifted through thousands of signals
from Sagittarius B2, a vast dust cloud at the centre of our galaxy.
While they failed to find evidence for amino acids, they did find a
substance called ethyl formate, the chemical responsible for the
flavour of raspberries. "It does happen to give raspberries their
flavour, but there are many other molecules that are needed to make
space raspberries," Arnaud Belloche, an astronomer at the Max Planck
Institute for Radio Astronomy in Bonn, told the Guardian. Curiously,
ethyl formate has another distinguishing characteristic: it also
smells of rum.
The astronomers used the IRAM telescope in Spain to analyse
electromagnetic radiation emitted by a hot and dense region of
Sagittarius B2 that surrounds a newborn star. Radiation from the star
is absorbed by molecules floating around in the gas cloud, which is
then re-emitted at different energies depending on the type of
molecule. While scouring their data, the team also found evidence for
the lethal chemical propyl cyanide in the same cloud. The two
molecules are the largest yet discovered in deep space.
Dr Belloche and his colleague Robin Garrod at Cornell University in
New York have collected nearly 4,000 distinct signals from the cloud
but have only analysed around half of these. "So far we have
identified around 50 molecules in our survey, and two of those had not
been seen before," said Belloche. The results are being presented
today at the European Week of Astronomy and Space Science at the
University of Hertfordshire.
Last year, the team came tantalisingly close to finding amino acids in
space with the discovery of a molecule that can be used to make them,
called amino acetonitrile. The latest discoveries have boosted the
researchers' morale because the molecules are as large as the simplest
amino acid, glycine. Amino acids are the building blocks of proteins
and are widely seen as being critical for complex life to exist
anywhere in the universe. "I wouldn't be surprised if we find an amino
acid out there in the coming years," said Belloche.
Previously, astronomers have detected a variety of large molecules,
including alcohols, acids and chemicals called aldehydes. "The
difficulty in searching for complex molecules is that the best
astronomical sources contain so many different molecules that their
'fingerprints' overlap and are difficult to disentangle," Belloche
said. The molecules are thought to form when chemicals that already
exist on some dust grains, such as ethanol, link together to make more
complex chains. "There is no apparent limit to the size of molecules
that can be formed by this process, so there's good reason to expect
even more complex organic molecules to be there," said Garrod.
CONTACT
Arnaud Belloche
http://www.mpifr-bonn.mpg.de/english/ueberInstitut/instMitarbeiter/index.html
email : bell...@mpifr-bonn.mpg.de
ETHYL FORMATE
http://www.physorg.com/news159548933.html
Highly complex organic molecules detected in space / 4.21.2009
Scientists from the Max Planck Institute for Radio Astronomy (MPIfR)
in Bonn, Germany, Cornell University, USA, and the University of
Cologne, Germany, have detected two of the most complex molecules yet
discovered in interstellar space: ethyl formate and n-propyl cyanide.
Their computational models of interstellar chemistry also indicate
that even larger organic molecules may be present - including the so-
far elusive amino acids, which are essential for organic life. The
results will be presented at the European Week of Astronomy and Space
Science at the University of Hertfordshire on Tuesday 21st April.
The IRAM 30 metre telescope in Spain was used to detect emissions from
molecules in the star-forming region Sagittarius B2, close to the
centre of our galaxy. The two new molecules were detected in a hot,
dense cloud of gas known as the "Large Molecule Heimat", which
contains a luminous newly-formed star. Large organic molecules of many
different sorts have been detected in this cloud in the past,
including alcohols, aldehydes, and acids. The new molecules, ethyl
formate (C2H5OCHO) and n-propyl cyanide (C3H7CN), represent two
different classes of molecule - esters and alkyl cyanides - and they
are the most complex of their kind yet detected in interstellar space.
Atoms and molecules emit radiation at very specific frequencies, which
appear as characteristic "lines" in the electromagnetic spectrum of an
astronomical source. Recognizing the signature of a molecule in that
spectrum is rather like identifying a human fingerprint. "The
difficulty in searching for complex molecules is that the best
astronomical sources contain so many different molecules that their
"fingerprints" overlap, and are difficult to disentangle" says Arnaud
Belloche, scientist at the Max Planck Institute and first author of
the research paper. "Larger molecules are even more difficult to
identify because their ‘fingerprints’ are barely visible: their
radiation is distributed over many more lines that are much weaker"
adds Holger Müller, researcher at the University of Cologne. Out of
3700 spectral lines detected with the IRAM telescope, the team
identified 36 lines belonging to the two new molecules.
The researchers then used a computational model to understand the
chemical processes that allow these and other molecules to form in
space. Chemical reactions can take place as the result of collisions
between gaseous particles; but there are also small grains of dust
suspended in the interstellar gas, and these grains can be used as
landing sites for atoms to meet and react, producing molecules. As a
result, the grains build up thick layers of ice, composed mainly of
water, but also containing a number of basic organic molecules like
methanol, the simplest alcohol.
"But," says Robin Garrod, a researcher in astrochemistry at Cornell
University, "the really large molecules don't seem to build up this
way, atom by atom." Rather, the computational models suggest that the
more complex molecules form section by section, using pre-formed
building blocks that are provided by molecules, such as methanol, that
are already present on the dust grains. The computational models show
that these sections, or "functional groups", can add together
efficiently, building up a molecular "chain" in a series of short
steps. The two newly-discovered molecules seem to have been produced
in this way.
Garrod adds, "There is no apparent limit to the size of molecules that
can be formed by this process - so there's good reason to expect even
more complex organic molecules to be there, if we can detect them."
Senior MPIfR team member Karl Menten thinks that this will happen in
the near future: "What we are doing now is like searching for a needle
in a haystack. Future instruments like the Atacama Large Millimeter
Array will allow much more efficient studies to discover organic
interstellar molecules." These may even include amino acids, which are
required for the production of proteins, and are therefore essential
to life on Earth.
The simplest amino acid, glycine (NH2CH2COOH), has been searched for
in the past, but has as yet not been successfully detected. However,
the size and complexity of this molecule is matched by the two new
molecules discovered by the team.
PREVIOUSLY ON SPECTRE --- SPACE SMELLS LIKE
http://spectregroup.wordpress.com/2008/02/27/space-smells-like/
THE SMELL OF MOONDUST
http://spectregroup.wordpress.com/2006/02/28/the-smell-of-moondust/
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