Scientists make an unexpected discovery
NASA's James Webb Space Telescope has discovered a «catastrophic» collision of giant asteroids around a nearby star, and scientists say it happened just 20 years ago in the Beta Pictoris star system.
NASA's James Webb Space Telescope was built to look back as far as 13.5 billion years into the past, but its latest discovery is surprisingly recent, reports the Daily Mail.
Only 20 years ago, two asteroids orbiting Beta Pictoris, a star located 63 light-years from Earth, collided, the $10 billion observatory reports.
The «catastrophic» collision turned two rocky bodies into small particles of dust, «smaller than pollen or powdered sugar.»
Collectively, these dust particles were about 100,000 times the size of the asteroid that wiped out the dinosaurs some 66 million years ago.
In our own solar system, asteroids collide with each other and even planets, threatening forms life, although there are currently no known worlds orbiting Beta Pictoris that could host aliens.
Beta Pictoris, which is nearly twice as massive as our sun and more than eight times its luminosity, has long been of interest to astronomers because it is relatively young.
Our sun is 4.5 billion years old, but Beta Pictoris is only 20 million years old, a key age for the formation of giant planets, but rocky planets can still form around it.
Scientists have already confirmed the presence of two gas planets, Beta Pictoris c and Beta Pictoris c. orbiting it, but any rocky planets have yet to be discovered.
“Beta Pictoris is at an age when planet formation in the terrestrial planet zone is still ongoing as a result of collisions with giant asteroids,” said Christine Chen, an astronomer at Johns Hopkins University in Baltimore, Maryland. “So what we could be observed here — this is basically how rocky planets and other celestial bodies form.»
Twenty years ago, NASA's retired Spitzer Space Telescope observed «enormous amounts of dust» around Beta Pictoris.
Along with Hubble, Compton and Chandra, Spitzer was one of NASA's four largest observatories — large, powerful space telescopes launched between 1990 and 2003.
At that time The dust around Beta Pictoris was thought to be the result of the constant movement of two small rocky bodies rubbing against each other.
But when Christine Chen and her colleagues studied the same area 20 years later using the James Webb Telescope, they discovered that that the dust has disappeared.
They believe that the powerful collision between the two asteroids produced ultrafine dust particles that gradually dispersed into space.
«We think that all this dust is what we originally saw in the Spitzer data from 2004 and 2005,» Chen said. «Given the new Webb data, the best explanation we have is that what we're actually seeing is the aftermath of a rare cataclysmic event between large asteroid-sized bodies.»
If rocky planets do exist in orbit around Beta Pictoris, they have yet to be found — or have not yet formed.
But the findings suggest that this distant system may be going through the same planet-forming process , the same as our solar system more than 4 billion years ago.
In young solar systems such as Beta Pictoris, «early upheavals» can influence atmospheric composition, water content and other key aspects of habitability that could eventually arise on their planets.
The team also takes its hat off to Spitzer, without which the dust from the collision would not have been detected.
“Most of the discoveries made by the James Webb Space Telescope involve what the telescope found directly,” said co-author Cicero Lu, a former Johns Hopkins doctoral student in astrophysics. “In this case, the story is a little different because our results are based on what James Webb did not see.»