Humans have dreamed about traveling to other star systems and setting foot on alien worlds for generations. To put it mildly, interstellar exploration is a very daunting task. As we explored in a previous post, it would take between 1000 and 81,000 years for a spacecraft to reach Alpha Centauri (of which Proxima Centauri is considered a companion) using conventional propulsion (or those that are feasible using current technology). On top of that, there are numerous risks when traveling through the interstellar medium (ISM), not all of which are well-understood.
In October 19th, 2017, the first interstellar object ever detected flew past Earth on its way out of the Solar System. Less than two years later, a second object was detected, an easily-identified interstellar comet designated as 2I/Borisov. The appearance of these two objects verified earlier theoretical work that concluded that interstellar objects (ISOs) regularly enter our Solar System.
The question of how often this happens has been the subject of considerable research since then. According to a new study led by researchers from the Initiative for Interstellar Studies (i4is), roughly 7 ISOs enter our Solar System every year and follow predictable orbits while they are here. This research could allow us to send a spacecraft to rendezvous with one of these objects in the near future.
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!
On July 14th, 2015, theNew Horizons mission made history when it became the first robotic spacecraft to conduct a flyby of Pluto. On December 31st, 2018, it made history again by being the first spacecraft to rendezvous with a Kuiper Belt Object (KBO) – Ultima Thule (2014 MU69). In addition, the Voyager 2probe recently joined its sister probe (Voyager 1) in interstellar space.
Given these accomplishments, it is understandable that proposals for interstellar missions are once again being considered. But what would such a mission entail, and is it even worth it? Kelvin F. Long, the co-founder of the Initiative for Interstellar Studies (i4iS) and a major proponent of interstellar flight, recently published a paper that supports the idea of sending robotic missions to nearby star systems to conduct in-situ reconnaissance.