Time Space Science

Many of the organic molecules that make up life on Earth have also been found in space. A University of Michigan astronomer will use the Herschel Space Observatory to study these chemical compounds in new detail in the warm clouds of gas and dust around young stars.
They hope to gain insights into how organic molecules form in space, and possibly, how life formed on Earth.

"The chemistry of space makes molecules that are the precursors of life. It's possible that the Earth didn't have to make these things on its own, but that they were provided from space," said Ted Bergin, an associate professor in the Department of Astronomy.

Bergin is a co-investigator on the Heterodyne Instrument for the Infrared aboard Herschel and a principal investigator on one of its key observing programs. Herschel, a European Space Agency mission with NASA participation, is scheduled to launch May 6. An orbiting telescope that will unlock new wavelengths on the electromagnetic spectrum, it will allow astronomers to observe at the far-infrared wavelengths where organic molecules and water emit their chemical signatures.

"We'll be studying the full extent of chemistry in space and we hope to learn what types of organics are out there as a function of their distance from a star," Bergin said. "And we want to understand the chemical machinery that led to the formation of these organics."

Meteorites flecked with amino acids, which make proteins, have fallen to Earth from space. In faraway galaxies and stellar nurseries, astronomers have detected complex organic sugar and hydrocarbon molecules that are key components in chlorophyll in plants and RNA. Bergin expects to detect tens if not hundreds of these kinds of compounds---some of which have never been found before outside the Earth.

He is also involved in a Herschel project to look for water molecules in space. Traces of water in warm clouds of gas and dust around young stars could hold clues to how water forms and behaves in space, and how this elixir of life came to be so abundant on Earth. Scientists believe water got to Earth in a similar way as organic molecules.

"Most of the water in the solar system is not where we are, but further out in the solar system," Bergin said. "Most theories suggest that the Earth formed dry and impacts from asteroids or other objects provided the water here."


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Astronomers have found three brown dwarfs with estimated masses of less than 10 times that of Jupiter, making them among the youngest and lowest mass sub-stellar objects detected in the solar neighbourhood to date.

The observations were made by a team of astronomers working at the Laboratoire d'Astrophysique de l'Observatoire de Grenoble (LAOG), France, using the Canada-France-Hawaii Telescope (CFHT). Andrew Burgess will be presenting the discovery at the European Week of Astronomy and Space Science at the University of Hertfordshire, Hatfield, on Wednesday 22nd April.

The dwarfs were found in a star forming region named IC 348, which lies almost 1000 light years from the Solar System towards the constellation of Perseus. This cluster is approximately 3 million years old – extremely young compared to our 4.5 billion year old Sun – which makes it a good location in order to search for the lowest mass brown dwarfs. The dwarfs are isolated in space, which means that they are not orbiting a star, although they are gravitationally bound to IC 348. Their atmospheres all show evidence of methane absorption which was used to select and identify these young objects.

"There has been some controversy about identifying young, low mass brown dwarfs in this region. An object of a similar mass was discovered in 2002, but some groups have argued that it is an older, cooler brown dwarf in the foreground coinciding with the line of sight. The fact that we have detected three candidate low-mass dwarfs towards IC 348 supports the finding that these really are very young objects," said Burgess.

The team set out to find a population of these brown dwarfs in order to help theoreticians develop more accurate models for the distribution of mass in a newly-formed population, from high mass stars to brown dwarfs, which is needed to test current star formation theories. The discovery of the dwarfs in IC 348 has allowed them to set new limits on the lowest mass objects.

"Finding three candidate low-mass dwarfs towards IC 348 backs up predictions for how many low-mass objects develop in a new population of stars. Brown dwarfs cool with age and current models estimate that their surfaces are approximately 900-1000 degrees Kelvin (about 600-700 degrees Celsius). That’s extremely cool for objects that have just formed, which implies that they have the lowest masses of any of this type of object that we’ve seen to date," said Burgess.


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