In 2017, astronomers first detected an interstellar object as it traversed the Solar System. They call him Oumuamua, but they saw it while it was leaving, so they had very few days to study it and try to establish its characteristics, provenance and nature, and that gave rise to all kinds of speculations. Two years later, it was the turn of a comet, called 2I/Borisov, the second object coming from other stars that until now has been able to be captured by man. Of course, scientists believe that there must be many more ‘visitors’ of this kind, although we are only now beginning to have the technology to discover them.
Being able to observe these objects in detail provides a unique opportunity to see how similar they are to those in our own system. By comparing them, we will also find out if all solar systems ‘work’ in the same way and with the same elements. Therefore, it is not surprising that many scientists have launched to propose missions capable of not only observing these interstellar wanderers, but also intercepting them.
That is exactly what an international team of scientists led by Amir Siraj y Avi Loebwhich in an article published on the server ArXiv, proposes how exactly that mission should be. A breakthrough if we ever want to build it.
For starters, interstellar visitors tend to behave quite strangely. It was not the case Borisovwhich as soon as it entered our system began to behave like a typical comet, but it did Oumuamua, which left more questions than answers. This strange rock, in fact, did not develop a tail, as scientists expected, and also exhibited an acceleration capacity that is inexplicable. It is not surprising that some of them, with their own Avi Loeb to the head, they thought that in reality it was a ship manufactured by some remote extraterrestrial civilization.
Something that could be true… or not. We simply do not yet have enough evidence to affirm or refute it. To avoid these types of claims, it would be best to be able to observe these objects closely. And to achieve this, you must be able to discover them first and then develop a mission capable of reaching them. Numerous astronomers are already working on both.
As Siraj, Loeb and their colleagues explain, telescopes like the Vera C. Rubin (LSST) will be able to detect between 1 and 10 interstellar objects like Oumuamua per year in the future, giving scientists plenty of choice when it comes to finding a ideal candidate to intercept. But what requirements will this ‘ideal candidate’ have to meet?
What should the new Oumuamua have?
The first is, without a doubt, its origin. The object has to come from a place (and approach at an angle) that is appropriate to the mission that will then need to intercept it. And according to the study, the best place to place this ‘interceptor’ is the L2 Lagrange point of the Earth-Sun system. Exactly, the same one where the James Webb Space Telescope.
And Lagrangian point it is a place where the gravitational forces of two objects (in this case the Earth and the Sun) balance each other, meaning that whatever is placed there will not be attracted to either. There are five such points in the Earth-Sun system, but the researchers believe that L2 is the most suitable because very little fuel is needed to stay in it, and it is very likely that any stellar interceptor would have to wait for years before it could reach it. the right occasion presents itself for action.
First, of course, the spacecraft would have to receive notice that an ‘accessible’ interstellar object is approaching. And that warning has to come from a telescope that is capable of detecting those objects in time. NASA, in fact, is already planning the construction of a 1.5-meter telescope (the Time Domain Spectroscopic Observatory, TSO), to also install point L2, next to the famous James Webb.
In fact, the Webb is not suitable for this job as, despite its immense power, it takes two to five days to focus, making it too slow to pick up fast-approaching objects. The TSO, however, can be focused in just a few minutes, and could also be complemented by another telescope, the Near Earth Object Surveyor, (EOS) which is destined to reside at the L1 Lagrange point of the Earth-Moon system.
Combined, these two fast-acting telescopes should be able to image any interstellar object that enters the Solar system with the proper orientation.
intercept the object
Once the object is detected, the next thing to do is to reach it. Many of the candidates picked up by the telescopes will be out of range, but the study authors estimate that there is an 85% chance that a spacecraft stationed at L2 could track down and intercept a suitable Oumuamua-sized object of interest within 10 years. Which is reasonable. Everything would be a matter of waiting patiently for the opportunity to present itself.
Once the spacecraft reaches the object, it could take a closer look at it, mapping the materials it’s made of, both natural and man-made, which could help settle the debate over whether some of those visitors from other stars are extraterrestrial-made probes. .
The ship could also search for any type of gas emission capable of explaining the mysterious forces observed in Oumuamua and thus determine at once whether or not it was of artificial origin.