Life on Other Planets? Astronomers Identify Largest Molecule Ever in Planet-Forming Disk

A precursor to an organic molecule that would give rise to life has been identified in a planet-forming gas disk around a young star called Oph-IRS 48. The dimethyl ether molecule found in the disk by the team is usually found in stars that form clouds.

Leiden Observatory Assistant Professor Nienke van der Marel told Newsweek: “Dimethyl ether is the largest molecule ever detected in a planet-forming disk. It has been seen before in cold clouds where stars form, but not yet in a medium where planets form.

The importance of the molecule discovered by astronomers

“This means that such molecules can reach the planets directly as soon as they form. The molecule is particularly important as it is a ‘complex organic molecule’ that is the starting point for large molecules, the building blocks of life, through further chemicals.”

“These results give us a better understanding of complex organic molecules and how they eventually come together,” said Nashanty Brunken, a Master’s student at the Leiden Observatory.

Because these molecules are the precursors of life’s building blocks, the results could help show which system and planet are more likely to host life. Brunken also said, “Complex organic molecules are precursors to pre-life molecules. This means that from molecules such as dimethyl ether, we can build larger and more complex molecules, such as amino acids and sugars, which are components of life.”

Credit: ALMA (ESO/NAOJ/NRAO) Nienke van der Marel)

‘All exoplanet systems have the potential to host life’

Alice Booth, a Leiden University astronomer and co-author of the paper, told Newsweek: “The detection of these complex molecules in the hot disk-like IRS 48, which they were unable to form in situ, is very convincing evidence for interstellar inheritance. This means that the complex molecules in the disks have an origin in the cold black cloud stage before stars form. If you can guess that, then it means that all exoplanet systems have the potential to host life.”

In the young star IRS 48, there is an asymmetrical, “dust trap” that has been caused by the birth of a planet or star between the parent star and the dust trap. In this zone, larger dust grains can become trapped and grow larger.

“This discovery tells us that large complex molecules are present where planets form, as the dust trap is probably located at the edge of a cavity carved out by a planet,” said Van der Marel, co-author of the study.

“The dust trap itself is a high concentration of dust grains that can transform into a group of planetoids, comets, or even a planet itself. Knowing that such molecules are found in the region of the disk where planets form tells us on which planets such molecules could end up and potentially develop life.”

The studies were carried out with the ALMA telescope located in the Atacama Desert in Chile. “The ALMA telescope has much higher sensitivity than other telescopes observing at these wavelengths,” van der Marel said.