Here’s a thorny problem: What if life doesn’t always appear on planets that can support it? What if we find more and more exoplanets and determine that some of them are habitable? What if we also determine that life hasn’t appeared on them yet?
Could we send life-bringing comets to those planets and seed them with terrestrial life? And if we could do that, should we?
When Canadian astronomer Robert Weryk discovered `Oumuamua passing through our Solar System with the Pan-STARRS telescope, in October 2017, it caused quite a stir. It was the first interstellar object we’d ever seen coming through our neighbourhood. The excitement led to speculation: what could it be?
There was lots of fun conjecture on its origins. Was it an alien spacecraft? A solar sail? Or something more prosaic?
We used to think we were the center of everything. That wasn’t that long ago, and even though we’ve made tremendous advancements in our understanding of our situation here in space, we still have huge blind spots.
For one, we’re only now waking up to the reality of interstellar objects passing through our Solar System.
In 2019, amateur astronomer Gennadiy Borisov discovered a comet, which now bears his name. There’s a long history of amateur astronomers discovering comets, as they approach our inner Solar System on their elongated orbits. But this one was different: it was moving much too fast to be gravitationally bound to the Sun.
It was an interstellar comet. And now, it looks like it has split into two chunks.
When the mysterious object known as ‘Oumuamua passed Earth in October of 2017, astronomers rejoiced. In addition to being the first interstellar object detected in our Solar System, but its arrival opened our eyes to how often such events take place. Since asteroids and comets are believed to be material left over from the formation of a planetary system, it also presented an opportunity to study extrasolar systems.
Unfortunately, ‘Oumuamua left our Solar System before any such studies could be conducted. Luckily, the detection of comet C/2019 Q4 (Borisov) this summer provided renewed opportunities to study material left by outgassing. Using data gathered by the William Herschel Telescope (WHT), an international team of astronomers found that 2I/Borisov contains cyanide. But as Douglas Adams would famously say, “Don’t Panic!”
When ‘Oumuamua passed through our Solar System two years ago, it set off a flurry of excitement in the astronomical community. Here was the first-ever interstellar object that be observed by human trackers, and the mysteries surrounding its true nature and composition led to some pretty interesting theories. There were even some proposals for a rapid mission that would be able to rendezvous with it.
And now that a second interstellar object – C/2019 Q4 (Borisov) – has been detected traveling through the Solar System, similar proposals are being made. One of them comes from a group of scientists from the Initiative for Interstellar Studies (i4is) in the UK. In a recent study, they assess the technical feasibility of sending a mission to this interstellar comet using existing technology, and found that there were a few options!