Researchers Aim to Build a Spacecraft Ready to Chase Interstellar Objects as They Pass Through the Solar System.
A team of scientists led by Abraham Loeb, an astrophysicist at Harvard University, has proposed the construction of an interceptor spacecraft capable of approaching the next asteroid or comet entering the Solar System. To date, astronomers have identified two such objects that have passed through the Solar System: the cigar-shaped interstellar object ‘Oumuamua, discovered in October 2017, and comet 2I/Borisov, discovered in August 2019.
Simulation of the cigar-shaped interstellar object ‘Oumuamua. (Image: ESO).
Sending a probe to investigate interstellar objects would allow astronomers to capture more accurate images of the object’s surface and even collect samples of gas escaping from comets like 2I/Borisov. However, by the time astronomers detect an interstellar object, it is often too late to design, build, and launch a spacecraft to intercept it, resulting in these objects typically gliding through the Solar System while taking many secrets with them.
To address this issue, researchers drafted and presented their proposal on the arXiv database on November 3. Their unpublished study suggests that a space agency like NASA should build and launch an interstellar interceptor ready in orbit around Earth. As soon as astronomers detect an incoming interstellar object, the probe could quickly fly to intercept the intruding object on its trajectory through the Solar System.
The most suitable location to store the interceptor in space is one of Earth’s Lagrange points. At these points, the gravitational forces of the two massive bodies, Earth and the Sun, cancel each other out, allowing smaller objects like satellites or asteroids to remain in a fixed position, according to NASA.
Abraham Loeb identified Lagrange Point L2, where NASA’s Hubble Space Telescope is located, as the ideal spot to park the spacecraft. This location allows the probe to intercept many different trajectories that the foreign object may take as it approaches Earth. The interceptor would remain in energy-saving mode, potentially for decades, until a suitable candidate is detected. At that point, scientists would direct the probe to the best location to intercept it.
Astronomers suspect that many interstellar objects pass through the Solar System each year without being detected. The construction of modern telescopes, such as the Vera C. Rubin Observatory in Chile, which is expected to be fully operational by early 2024, will facilitate the detection of more such objects. It is predicted that Vera C. Rubin could detect 1 to 10 interstellar objects each year.
