'Cataclysmic' collision of giant asteroids discovered by scientists a 'unique glimpse' into how planets are formed

Evidence of a "cataclysmic" collision of giant asteroids which took place just 20 years ago has been found by scientists.

Astronomers said the event could help them to further understand how Earth and other planets are formed.

The collision happened in Beta Pictoris, a bright star system in the constellation of Pictor around 63 light years away. One light year is equal to nearly six trillion miles.

Researchers have been studying the system, which is 20 million years old, for more than three decades.

The evidence was found from latest data captured by the James Webb Space Telescope (JWST), which was launched in 2021 as part of a joint mission between NASA, the European Space Agency and the Canadian Space Agency.

The collision would have occurred just before another NASA telescope, Spitzer, gathered data from the region between 2004 and 2005, astronomers said.

Dust disappearance

The data showed some previously observed dust around Beta Pictoris had disappeared - while experts said the findings represented a change in how they understood the star system.

Christine Chen, an astronomer at Johns Hopkins University in the US who led the research, said: "The best explanation we have is that, in fact, we witnessed the aftermath of an infrequent, cataclysmic event between large asteroid-size bodies, marking a complete change in our understanding of this star system."

The violent clashes would have crushed some of the larger space rocks into fine dust particles smaller than pollen or powdered sugar, the researchers said.

They added the amount of dust generated would have been about 100,000 times the size of the asteroid that killed the dinosaurs.

In the aftermath of the explosion, Spitzer's instruments were able to identify the dust closest to the star by looking at their heat signatures.

Read more on Sky News:
'Super fluffy' candy floss planet discovered
Space images help experts understand changing universe

But gradually, this dust started to cool off as it moved far enough away from the star to become undetectable by JWST two decades later.

Conclusions from the unseen

Cicero Lu, a former PhD student in astrophysics at Johns Hopkins University, said: "Most discoveries by JWST come from things the telescope has detected directly.

"In this case, the story is a little different because our results come from what JWST did not see."

The researchers said the findings, presented at the 244th meeting of the American Astronomical Society in the US, offer a "unique glimpse" into how the solar system came into existence more than four billion years ago and whether it is unique.