ALMA Telescope Captures 'Teenage' Years of New Worlds

New astronomical survey captures previously unknown growing pains in the lives of planets To the point New Discoveries: Astronomers have captured detailed images of young planetary systems, revealing their growth stages and complexities. Significant Findings: The ALMA survey provides insights into debris discs, which represent the formative phase of planet formation, akin to the teenage years of planetary systems. Historical Insights: The results highlight chaotic periods in planetary development, helping to understand the evolution of our Solar System. Astronomers have, for the first time, captured a detailed snapshot of planetary systems in an era long shrouded in mystery. The ALMA survey to Resolve exoKuiper belt Substructures (ARKS), using the Atacama Large Millimeter/submillimeter Array (ALMA), has produced the sharpest images ever of 24 debris discs, the dusty belts left after planets finish forming. These discs are the cosmic equivalent of the teenage years for planetary systems - somewhat more mature than newborn, planet-forming discs, but not yet settled into adulthood. A missing link in planetary family albums "We've often seen the 'baby pictures' of planets forming, but until now, the 'teenage years' have been a missing link," says Meredith Hughes, an Associate Professor of Astronomy at Wesleyan University, Middletown, Connecticut, USA and co-PI of this study. "Debris discs are representing the collision-dominated phase of the planet formation process," explains Thomas Henning, MPIA (Max Planck Institute for Astronomy) scientist and another ARKS co-PI. "With ALMA, we are able to characterise the disc structures pointing to the presence of planets. In parallel, with direct imaging and radial velocity studies, we are searching for young planets in these systems." Our own Solar System's counterpart to this phase is the Kuiper Belt, a ring of icy debris beyond Neptune that preserves a record of massive collisions and planetary migrations from billions of years ago. By studying 24 exoplanetary debris belts, the ARKS team has opened a window into what our Solar System went through as the Moon was forming and as planets jostled for their final places, and sometimes trading orbits! Teenage discs: hard to "photograph," impossible to ignore Debris discs are faint, hundreds or even thousands of times dimmer than the bright, gas-rich discs where planets are born. The ARKS team overcame these challenges and produced images of these discs in unprecedented detail. Like teenagers dodging the camera, these faint discs have managed to hide from astronomers for years. But thanks to ALMA, astronomers can now see their complex structures: belts with multiple rings, wide smooth halos, sharp edges, and even unexpected arcs and clumps. However, ALMA, with its dozens of individual radio telescopes, does not take pictures in the classical sense. Instead, it collects radio signals emitted by dust particles and molecules, which have to be processed and correlated afterwards. Each telescope contributes to the final image, synthesised from the stream of radio waves. However, with its dozens of individual radio telescopes, ALMA does not produce images in the traditional sense. Instead, it collects radio signals emitted by dust particles and molecules, which then have to be processed and correlated. Each telescope contributes to the final image, which is correlated from the stream of radio waves. This complicated imaging process is also known as radio interferometry. The advantage is that the diameter of the network is significantly larger than that of a single telescope, thus allowing for a higher spatial resolution. This is necessary in order to image the sub-structures in the disks. The light-collecting area of the individual telescopes and the number of antennas in the network determine whether the network can actually see the disks. With over 50 antennas, each twelve meters in diameter, and twelve antennas seven meters in diameter, the researchers achieve the necessary sensitivity with ALMA. "We're seeing real diversity - not just simple rings, but multi-ringed belts, halos, and strong asymmetries, revealing a dynamic and violent chapter in planetary histories," adds Sebastián Marino, program lead for ARKS, and an Associate Professor at the University of Exeter, UK. Implications: your Solar System was once a wild ride The ARKS results show this teenage phase is a time of transition and turmoil. "These discs record a period when planetary orbits were being scrambled and huge impacts, like the one that forged Earth's Moon, were shaping young solar systems," says Luca Matrà, a co-PI on the survey, and Associate Professor at Trinity College Dublin, Ireland. By looking at dozens of discs around stars of different ages and types, ARKS helped decode whether chaotic features are inherited, sculpted by planets, or arise from other cosmic forces. Answering these questions could reveal whether our Solar System's history was unique, or the norm. Looking ahead: hunting for planetary architects The ARKS survey's findings are a treasure trove for astronomers hunting for young planets and seeking to understand how planet families, like our own, are built and rearranged. "This project gives us a new lens for interpreting the craters on the Moon, the dynamics of the Kuiper Belt, and the growth of planets big and small. It's like adding the missing pages to the Solar System's family album," adds Hughes. MN for MPIA / BEU for MPG Background information Highlights and firsts from ARKS