Essential amino acid for humans found in interstellar space
The building blocks of proteins could also be the building blocks of star systems.
Even in interstellar space, amino acids continue to be made.
Image credit: Jorge Rebolo-Iglesias. Background image: NASA/Spitzer Space Telescope ( CC BY 4.0 )
Astronomers have discovered one of the 20 essential amino acids for humans in the Perseus Molecular Complex, a star-forming region 1,000 light-years from Earth. The amino acid in question is called tryptophan : it is crucial for the growth of the baby and, in adults, it is used to make proteins and enzymes, as well as muscle and neurotransmitters.
The entire molecular complex of Perseus is invisible to us and to regular optical instruments, but not to infrared instruments where it shines brightly. And that’s great news when looking for molecules like tryptophan, which has a distinctive light signature when viewed in the infrared. Therefore, it was chosen as a potentially interesting target.
Using data from the now-retired Spitzer telescope , the astronomers looked at observations of the IC348 region where some 400 stars have formed. As in other star-forming regions, most stars are low-mass, and Spitzer had previously found that half of them had material orbiting the stars. About 120 of those stars are disks from when they formed, just 2 million years ago.
“The evidence for tryptophan in the Perseus molecular complex should encourage further effort to identify other amino acids in this region and in other star-forming regions. It is a very exciting possibility that the building blocks of proteins are widely present in the gas from which stars and planets form, it may be key to the development of life in exoplanetary systems,” the lead author said in a statement . , Dr. Susana Iglesias-Groth, from the Instituto de Astrofísica de Canarias.
Amino acids have been found in many space environments, such as meteorites , asteroids , and comets. They are found in extreme places like the atmosphere of Venus , so the discovery in interstellar space is not as dramatic. Around IC348, they are a pleasant 7 °C (44.6 °F), which is not bad for interstellar space. This measurement is in agreement with the previous observations of Dr. Iglesias-Groth, who measured the temperature of the hydrogen and water molecules present in the interstellar cloud.
While not dramatic or unexpected, the tryptophan discovery tells us that amino acids are common. They are there because planetary systems have not yet formed and may play a role in their chemistry, just as they played a role in the chemistry of life here on Earth.
