MYSTERIES OF THE UNIVERSE : WHAT DISTURBED A DISTANT STAR SYSTEM?

Astronomers are a step closer to understanding how our Solar System formed, all thanks to a chance encounter

- David Crookes

One of the greatest mysteries that astronomers hope to one day solve is how our Solar System formed. It’s long been known that star systems are shaped by collisions and other disruptive events, so whenever scientists are lucky enough to directly observe such an occurrence, it takes researchers one step closer to the answer.

In 2021, scientists made a breakthrough. They used the Atacama Large Millimeter/ submillimeter Array (ALMA), along with the Karl G. Jansky Very Large Array (VLA), to peer at the Z Canis Majoris (Z CMa) star system. They wanted to study a stream of dust and gas that was stretching far into the darkness of space. In doing so they happened to capture an object which they could see had smashed into the protoplanetary disc of leftover material surrounding the protostar pair, and it got them very excited indeed.

Although astronomers had previously observed the effects of the collision – the streamer, as it’s referred to – this time researchers found something else. “We detected it almost purely by chance,” says Ruobing Dong, an astronomer at the University of Victoria in Canada and principal investigator of the study. “It was like going on a hiking trip, finding a beautiful leaf on a tree and taking a photo of it, only to examine the photo afterwards and find lightning in the background sky.”