ASTRONOMERS searching for the building blocks of life in a giant dust cloud at the heart of the Milky Way have concluded that they taste vaguely of raspberries.
The discovery follows years of work by astronomers who trained their 30-metre Spanish 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," Dr Arnaud Belloche, an astronomer at the Max Planck Institute for Radio Astronomy in Bonn, said.
Ethyl formate has another distinguishing characteristic: it also smells of rum.
While scouring their data, the team 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 about 4000 distinct signals from the cloud. "So far we have identified around 50 molecules in our survey, and two of those had not been seen before," said Dr Belloche.
The results were presented yesterday 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 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," Dr Belloche said.
European astronomers also announced the discovery of the lightest planet yet found circling another star.
Michel Mayor, of Switzerland's Geneva Observatory, said the planet, named Gliese 581 e, has a mass just 1.9 times that of Earth.
Although probably rocky, like Earth, there is little chance of it being inhabited as it is so close to its parent star that its year lasts just 3.15 days. The planet is one of four known to circle the star, 20.5 light years from Earth.
The astronomers also confirmed that the star's fourth planet, Gliese 581 d, orbits in the "habitable zone", where it is neither too hot or too cold for water, and thus "could even be covered by a large and deep ocean".
Guardian News & Media 2009