Free Astronomy Magazine May-June 2022

39 MAY-JUNE 2022 ASTRO PUBLISHING By studying their formation and evolution, researchers can therefore gain a better understanding of how prebiotic molecules end up on plan- ets, including our own. “We are in- credibly pleased that we can now start to follow the entire journey of these complex molecules from the clouds that form stars, to planet- forming discs, and to comets. Hope- fully with more observations we can get a step closer to understanding the origin of prebiotic molecules in our own Solar System,” says Nienke van der Marel, a Leiden Observatory researcher who also participated in the study. Future studies of IRS 48 with ESO’s Extremely Large Telescope (ELT), cur- rently under construction in Chile and set to start operations later this decade, will allow the team to study the chemistry of the very inner re- gions of the disc, where planets like Earth may be forming. A nnotated image from the Atacama Large Millimeter/submil- limeter Array (ALMA) showing the dust trap in the disc that surrounds the system Oph-IRS 48. The dust trap provides a safe haven for the tiny dust particles in the disc, allowing them to clump together and grow to sizes that allow them to survive on their own. The green area is the dust trap, where the big- ger particles accumulate. The size of the orbit of Neptune is shown in the upper left corner to show the scale. [ALMA (ESO/NAOJ/NRAO)/Nienke van der Marel] T his video zooms in on the Oph- IRS 48 system, a star surrounded by a planet-forming disc that con- tains a dust trap. This trap allows dust particles to grow and spawn bigger bodies. [ALMA (ESO/NAOJ/ NRAO)/Nick Risinger (skysurvey.org) / Digitized Sky Survey 2/S. Guisard (www.eso.org/~sguisard) ] ! tected in star- forming re- gions may also be lurking on icy structures in planet-forming discs. These molecules are the precursors of prebiotic molecules such as amino acids and sugars, which are some of the basic building blocks of life. H ow do the ingredients for life end up on planets? The dis- covery of the largest molecule ever found in a planet- forming disc is providing clues. [ESO] cules. It was in this region of the disc that ALMA has now spotted signs of the dimethyl ether molecule: as heating from IRS 48 sublimates the ice into gas, the trapped molecules inherited from the cold clouds are freed and become detectable. “What makes this even more excit- ing is that we now know these larger complex molecules are avail- able to feed forming planets in the disc,” explains Booth. “This was not known before as in most systems these molecules are hidden in the ice.” The discovery of dimethyl ether suggests that many other complex molecules that are commonly de-