Dec 19, 2025 05:15 AM
https://www.eurekalert.org/news-releases/1109998
INTRO: In an unprecedented celestial event, NASA’s Hubble Space Telescope (HST) captured the dramatic aftermath of colliding space rocks within a nearby planetary system.
When astronomers initially spotted a bright object in the sky, they assumed it was a dust-covered exoplanet, reflecting starlight. But when the “exoplanet” disappeared and a new bright object appeared, the international team of astrophysicists — including Northwestern University’s Jason Wang — realized these were not planets at all. Instead, they were the illuminated remains of a cosmic fender bender.
Two distinct, violent collisions generated two luminous clouds of debris in the same planetary system. The discovery offers a unique real-time glimpse into the mechanisms of planet formation and the composition of materials that coalesce to form new worlds.
The study will be published on Thursday (Dec. 18) in the journal Science.
“Spotting a new light source in the dust belt around a star was surprising. We did not expect that at all,” Wang said. “Our primary hypothesis is that we saw two collisions of planetesimals — small rocky objects, like asteroids — over the last two decades. Collisions of planetesimals are extremely rare events, and this marks the first time we have seen one outside our solar system. Studying planetesimal collisions is important for understanding how planets form. It also can tell us about the structure of asteroids, which is important information for planetary defense programs like the Double Asteroid Redirection Test (DART).”
“This is certainly the first time I’ve ever seen a point of light appear out of nowhere in an exoplanetary system,” said lead author Paul Kalas, an astronomer at the University of California, Berkeley. “It’s absent in all of our previous Hubble images, which means that we just witnessed a violent collision between two massive objects and a huge debris cloud unlike anything in our own solar system today.” (MORE - details, no ads)
INTRO: In an unprecedented celestial event, NASA’s Hubble Space Telescope (HST) captured the dramatic aftermath of colliding space rocks within a nearby planetary system.
When astronomers initially spotted a bright object in the sky, they assumed it was a dust-covered exoplanet, reflecting starlight. But when the “exoplanet” disappeared and a new bright object appeared, the international team of astrophysicists — including Northwestern University’s Jason Wang — realized these were not planets at all. Instead, they were the illuminated remains of a cosmic fender bender.
Two distinct, violent collisions generated two luminous clouds of debris in the same planetary system. The discovery offers a unique real-time glimpse into the mechanisms of planet formation and the composition of materials that coalesce to form new worlds.
The study will be published on Thursday (Dec. 18) in the journal Science.
“Spotting a new light source in the dust belt around a star was surprising. We did not expect that at all,” Wang said. “Our primary hypothesis is that we saw two collisions of planetesimals — small rocky objects, like asteroids — over the last two decades. Collisions of planetesimals are extremely rare events, and this marks the first time we have seen one outside our solar system. Studying planetesimal collisions is important for understanding how planets form. It also can tell us about the structure of asteroids, which is important information for planetary defense programs like the Double Asteroid Redirection Test (DART).”
“This is certainly the first time I’ve ever seen a point of light appear out of nowhere in an exoplanetary system,” said lead author Paul Kalas, an astronomer at the University of California, Berkeley. “It’s absent in all of our previous Hubble images, which means that we just witnessed a violent collision between two massive objects and a huge debris cloud unlike anything in our own solar system today.” (MORE - details, no ads)