Scientists make plans to intercept an interstellar object: ScienceAlert

We finally have the technological means to detect interstellar objects. We have discovered two in recent years’Oumuamua and 2I/Borisovand no doubt there are more.

As such, there has been a lot of interest in developing a mission that could visit one as soon as we detect it. But what would such a mission look like?

Now, a design paper from a team of mostly American scientists who have attempted to answer that question and bring us one step closer to launching such a mission.

Part of what makes an interstellar visitor mission interesting is that interstellar visitors are so weird. Borisov behaved like a typical comet when he entered the solar system, but ‘Oumuamua was a very different beast.

It never developed a comet tail, as many scientists had expected. It also showed an acceleration that didn’t seem to be explained by radiation or other means, leading some leading scientists to argue that it might even be an alien probe.

The best way to combat such fanciful claims is to scrutinize them. And to do that, we need to have a mission that can catch it. But first we should see it, and astronomers are already working on that.

The Vera C Rubin Observatory Legacy Survey of Space and Time (LSST) can detect anywhere from 1-10 interstellar objects about the size of ‘Oumuamua each year, according to the authors’ calculations.

That is plenty of opportunity to find the right candidate. But what criteria must the candidate meet?

The most important would be, “Where did it come from?” While there is no “best” angle for an interstellar object (ISO) to approach from, it does make a difference based on where we store the “interstellar interceptor” (ISI).

According to the paper, the best place for that is most likely the Earth-Sun L2 Lagrange point. It has more than one advantage: first, it takes very little fuel to stay in the station, and any ISI may have to wait in storage mode for years.

Once called into action, it has to react quickly, and another resident of L2 can help it with that.

NASA’s Time-domain Spectroscopic Observatory (TSO) is a 1.5m telescope planned to locate at the L2 Lagrange point, along with better-known telescopes such as the JWST.

For all its amazing ability to capture spectacular images, JWST has one major weakness: it’s slow. It can take 2-5 days to focus on a specific object, making it useless when tracking ISOs. TSO, on the other hand, only takes a few minutes.

It could be complemented by another telescope, the planned Near Earth Object Surveyor, which is intended to reside at the L1 Lagrange point of the Earth-moon system.

In conjunction with the TSO, these two fast-response telescopes should be able to capture images from any ISO entering the Solar System’s interior that is not directly on a trajectory along the L1-L2 baseline.

Once detected, the next task is to go to the ISO. Some, unfortunately, will simply be out of reach from an orbital mechanics point of view.

But the authors calculate that there is an 85 percent chance that an ISI stored at L2 will be able to find a suitable object of interest the size of ‘Oumuamua within 10 years.

So, essentially, once we’re able to detect ISOs, it’s just a matter of patiently waiting for the right opportunity.

Once the ISI reaches ISO, it can begin close-range observation, including a full spectroscopic map of both natural and man-made materials, which could help resolve the debate over whether such objects were created by aliens.

It can also check for any outgassing that could explain the mysterious forces acting on ‘Oumuamua.

There are undoubtedly many more exciting things scientists would like to understand about the first interstellar object we visit.

But based on the calculations in this article, there will be plenty of opportunities to do this and a lot of data to collect if we do. Time to move on to the planning phase, then!

This article was originally published by Universe today. Read the original article.