Fortunately, this catastrophe did not occur in our solar system, but rather in a young planetary system around the star Beta Pictoris, which is more than sixty light-years away. Smaller celestial bodies often collide there, but according to Christopher Stark of NASA’s Goddard Space Flight Center, traces of a large collision in the very recent past have now been found.
A flat disk of dust, gravel, rocks, boulders, and asteroids orbiting Beta Pictoris. The first indications of this were found in 1984 by the Dutch-American infrared satellite IRAS. Since then, the disk has been studied extensively; From the ground we look at it almost from the side. Two complete giant planets were also discovered in the disk.
Last year, the dust disk of Beta Pictoris was also imaged by the infrared cameras of the James Webb Space Telescope. These record slight thermal radiation from small dust particles. To everyone’s surprise, the infrared images revealed a strange streak of dust that appeared to protrude diagonally from the disk.
According to Stark and his colleagues, the “cat’s tail,” as the remarkable structure has been called, is a short side view of a wide fan of debris, resulting from a recent collision. “They must be asteroids at least a hundred kilometers in size,” Stark said in a press conference last Wednesday.ste American Astronomical Society meeting in New Orleans.
The fact that this is a fairly recent event also fits well with previous measurements of carbon monoxide molecules in the dust disk. They have a relatively short lifetime, but when asteroids crash they are released in large quantities.
According to Reince Waters of Radboud University in Nijmegen, the Webb telescope is the first to observe these types of weak structures. “The entire dust disk of Beta Pictoris must be the result of collisions between smaller celestial bodies,” he says. “So it is very likely that there was a larger collision recently.”
However, there is no 100 percent certainty yet, according to Waters. “The challenge to me seems to be to understand the spatial structure of the cat’s tail and the time scale over which it remains visible after impact.”
Stark is optimistic. “If our idea is correct, we should be able to measure a simple shift in a cat’s tail within a few years,” he says. Furthermore, he hopes to use the Webb telescope to detect similar structures in dust disks around other young stars nearby.
