Astronomers discovered the essential amino acid tryptophan in the molecular complex of Perseus, a star-forming region 1,000 light years from Earth. This discovery was another step toward understanding the origin of life in the Universe.
Tryptophan is crucial for child growth, and in adults it is used to produce proteins and enzymes, as well as muscle and neurotransmitters. It was chosen as a potentially interesting target because it has a characteristic light signature in the infrared range.
Using data from the Spitzer telescope, astronomers examined observations of the IC348 region, where about 400 stars have formed. As in other star-forming regions, most of the stars have low mass, and Spitzer previously found that half of them have matter orbiting the stars. About 120 of these stars are disks when they formed, that is, only 2 million years ago.
Evidence of tryptophan in the Perseus molecular complex should stimulate additional efforts to identify other amino acids in this area and in other areas of star formation. Which stars and planets form may be key to the development of life in exoplanetary systems.
Amino acids have been found in many cosmic environments, such as meteorites, asteroids, and comets. They are found in extreme places, such as the atmosphere of Venus, so the discovery in interstellar space is not as dramatic. Near IC348 they have a nice temperature of 7° C (44.6° F), which is not bad for interstellar space. This measurement is consistent with previous observations by Dr. Iglesias-Groth, who measured the temperature of hydrogen and water molecules present in the interstellar cloud.
The discovery of tryptophan is neither dramatic nor unexpected, but it tells us that amino acids are widespread. They are there because planetary systems have not yet formed, and they may play a role in their chemical composition, just as they have played a role in the chemical composition of life here on Earth.