Prove the basic building block for the emergence of life in the protoplanetary disk

Updated 03/09/2022 at 2:20 pm

• It is the largest organic molecule ever discovered in a protoplanetary disk.
• At a distance of 444 light years, researchers discovered dimethyl ether.
• There are probably bigger and more complex molecules out there.

More space themes can be found here

Located 444 light-years away, the star IRS 48 is surrounded by a disk of gas and dust in which planets are believed to form. This disc also contains the first building blocks of life. A research team from the Leiden Observatory in the Netherlands and the Max Planck Institute for Extraterrestrial Physics in Garching near Munich has discovered the nine-atom molecule dimethyl ether (CH3OCH3) in a protoplanetary disk for the first time. The scientists wrote in the Journal of Astronomy and Astrophysics that there are likely to be larger and more complex particles out there.

Complex organic molecules can form in dense gas clouds

Astronomers have long known that complex organic molecules can actually form in the dense gas clouds, of which stars are formed. “Organic” are carbon compounds that act as the building blocks of life. So it was assumed that these building blocks would fall from star-forming regions on emerging planets – provided the conditions were right – that could give rise to life. Then it will be possible to detect complex organic compounds in the protoplanetary disks as well. However, so far this has only been possible using very simple compounds such as methanol.

With the discovery of dimethyl ether, researchers have now taken a huge step forward. “We’re also learning something about the origin of life on our planet,” explains Nasante Bronken of the Leiden Observatory. “And we are getting a better idea of ​​the possibility of life in other planetary systems.”

And her colleague Alice Booth adds: “We now know that such large complex particles are available to fall off the forming planets. We didn’t know that until now, because these particles hide in layers of ice around the dust grains.”

“Dustfall” of the star IRS 48 is particularly interesting to researchers

Brunken, Booth and their colleagues targeted the star IRS 48 precisely because its protoplanetary disk hosts a “dust trap”: a region where many dust grains accumulate, likely due to the gravity of the forming planet. In such an environment, these dust grains are surrounded by layers of ice, which can also contain larger organic molecules. If the ice evaporates due to the radiation from the young star, these particles are released – and the researchers hope they can be detected.

The team was successful with the ALMA International Large Radio Telescope Facility in Chile: the astronomers were able to capture the radiation of the evaporation of particles of dimethyl ether. During their observations, they also encountered radiation indicating the eight-atom organomethyl molecule.

Prebiotic molecules such as amino acids and polysaccharides can be composed of these molecules – important building blocks for the development of life. “We can now trace these particles from star-forming regions through protoplanetary disks to comets,” summarizes Nienke van der Marel of the Leiden Observatory. “This also gives us a better understanding of the source of the prebiotic molecules in our solar system.”
© dpa