Searching space for clues to life on Earth

U. MICHIGAN (US)—In a mission to learn more about how life formed on Earth—and how organic molecules form in space—astronomers will use the Herschel Space Observatory, scheduled to launch May 6, to study the chemistry of warm gas and dust clouds around young stars.

Herschel, a European Space Agency mission with NASA participation, is an orbiting telescope designed to 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.

“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,” says Ted Bergin, an associate professor in the Department of Astronomy at the University of Michigan. Bergin is a coinvestigator on the Heterodyne Instrument for the Infrared aboard Herschel and a principal investigator on one of its key observing programs.

“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 explains. “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 says. “Most theories suggest that the Earth formed dry and impacts from asteroids or other objects provided the water here.”

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