Friday, February 3, 2023 | Back issues
Courthouse News Service Courthouse News Service

Researchers find the largest molecule ever spotted in planet-forming disk

The molecule — dimethyl ether — comes complete with nine different atoms and is a cosmic percussor to other molecules that have led to the blooming of life itself.

(CN) — For the first time ever, researchers have found dimethyl ether — a grandfather molecule to some essential life building blocks in the universe — in a planet-forming disk over 400 light years away.

Dimethyl ether, while commonly used here on Earth to help with organic synthesis, has proven somewhat elusive in the expanse of space. A larger molecule with nine atoms and the most chemically simple form of ether we know of, dimethyl ether has never been observed in the giant gaseous disks that form planets. They’re quite commonly found in star-forming clouds, but for a long time experts assumed they would never be able to find them in planet-forming disks.

That all changed on Tuesday, however, when researchers revealed in a study in Astronomy & Astrophysics they had found the molecule in one of those disks for the first time.

"It is really exciting to finally detect these larger molecules in disks,” said Alice Booth, researcher at Leiden Observatory and co-author of the study. “For a while we thought it might not be possible to observe them.”

Researchers made this discovery using instruments from the Atacama Large Millimeter/submillimeter Array (ALMA) at the European Southern Observatory in Chile. They found dimethyl ether in a disk close to the star IRS 48, a relatively young star nestled in the Ophiuchus constellation about 444 light years from Earth.

Even before Tuesday’s breakthrough announcement, IRS 48 had already been making a name for itself. The disk around the star has become famous for having a strangely nut-shaped dust trap that contains countless tiny grains of dust. While no larger than a fraction of an inch, researchers have found these flecks of space dust could collect to form entirely new comets, asteroids and perhaps even planets over time.

They’ve also found that this region functions as a kind of icy trap. In the frigid temperatures of the planet-forming space, molecules like carbon monoxide cling to the dust specks and coat them in ice, creating a type of ice reservoir within the star’s disk.

It was here that researchers found the dimethyl ether they were looking for. They found that heat from the nearby star was warming up the dust enough to convert the ice layer into gas, releasing the molecules trapped inside and allowing researchers to spot them for the first time.

Nashanty Brunken, master's student at Leiden Observatory and lead author of the study, says these findings not only reveal the largest molecule ever detected in a planet-forming disk, but could teach us entirely new lessons on the origins of life itself.

"From these results, we can learn more about the origin of life on our planet and therefore get a better idea of the potential for life in other planetary systems,” Brunken said. “It is very exciting to see how these findings fit into the bigger picture.”

This is because molecules like dimethyl ether have been known to predate some of the most important atoms in the universe. These molecules were the cosmic ancestors to prebiotic molecules — things like amino acids, sugars and fats — that are necessary for some of the simplest recipes to life we know of.

Researchers suggest there might be quite a lot more discoveries like this going forward. The existence of dimethyl ether around IRS 48 indicates there could be a host of other molecules living inside the icy environments of planet-forming disks.

Experts are hopeful that as we search for these treasures and try to understand how they arrived there, we might in turn discover how those building blocks arrived at our own planet — and where else in the cosmos they might be lurking.

“We are incredibly pleased that we can now start to follow the entire journey of these complex molecules from the clouds that form stars, to planet-forming disks, and to comets,” said Nienke van der Marel, a Leiden Observatory researcher. “Hopefully with more observations we can get a step closer to understanding the origin of prebiotic molecules in our own Solar System.”

Read the Top 8

Sign up for the Top 8, a roundup of the day's top stories delivered directly to your inbox Monday through Friday.

Loading
Loading...