Astronomers observed a giant asteroid collision at Beta Pictoris, using data from the Webb and Spitzer telescopes. The event, which occurred 20 years ago, offers new insights into the early formation of planets in this young star system. (Artist’s concept.) Credit: NASA
New observations shed light on the volatile processes that shape star systems like ours, offering unique insight into the primordial stages of planetary formation.
Astronomers have captured a snapshot of a giant asteroid collision in Beta Pictoris, revealing information about early planet formation. The study, using data from the James Webb and Spitzer space telescopes, tracked changes in dust around the star. The results suggest a massive collision that occurred 20 years ago, changing our understanding of the development of this young star system.
Massive collision in the Beta Pictoris star system
Astronomers have captured what appears to be a snapshot of a massive giant asteroid collision in Beta Pictoris, a nearby star system known for its early age and tumultuous planet-forming activity.
The observations shed light on the volatile processes that shape star systems like ours, providing unique insight into the primordial stages of planetary formation.
“Beta Pictoris is at an age where planet formation in the terrestrial planet zone is still occurring through giant asteroid collisions. So what we might be seeing here is basically how rocky planets and other bodies are forming in real time,” said research scientist Christine Chen. Johns Hopkins University astronomer who led the research.
The findings were presented June 10 at the 244th meeting of the American Astronomical Society in Madison, Wisconsin.
Two different space telescopes took snapshots 20 years apart of the same area around the star called Beta Pictoris. Scientists hypothesize that the massive amount of dust seen in the 2004-2005 Spitzer Space Telescope image indicates a collision of asteroids that had largely dissipated by the time the James Webb Space Telescope captured its images in 2023. Credit: Roberto Molar Candanosa/Johns Hopkins University, with Beta Pictoris concept art by Lynette Cook/NASA
Significant changes in dust energy signatures
Chen’s team spotted significant changes in the energy signatures emitted by dust grains around Beta Pictoris by comparing new data from the
” data-gt-translate-attributes=”({“attribute”:”data-cmtooltip”, “format”:”html”})” tabindex=”0″ role=”link”>James Webb Space Telescope with Spitzer Space Telescope observations from 2004 and 2005. Using Webb’s detailed measurements, the team tracked the composition and size of dust particles in the exact area previously analyzed by Spitzer.
Focusing on the heat emitted by crystalline silicates – minerals commonly found around young stars as well as on Earth and other celestial bodies – scientists found no trace of the particles previously observed in 2004- 2005. This suggests that a cataclysmic collision occurred between asteroids and other objects about 20 years ago, pulverizing the bodies into fine dust particles smaller than pollen or powdered sugar, Chen said.
The Beta Pictoris star system
Beta Pictoris is a young star system located approximately 63 light years from Earth in the constellation Pictor. Known to be about 20 million years old, which is significantly younger than our 4.5 billion-year-old solar system, Beta Pictoris is of particular interest to astronomers who study planetary formation. The system hosts a prominent debris disk, indicative of ongoing planetary formation, and has at least two known gas giants, Beta Pictoris b and c. Dynamic processes within Beta Pictoris, including frequent collisions and spatial weathering, provide valuable insights into the early stages of planetary development and terrestrial planet formation.
Evidence of cataclysmic collision
“We think all this dust is what we initially saw in the 2004 and 2005 Spitzer data,” said Chen, who is also an astronomer at the Space Telescope Science Institute. “With Webb’s new data, the best explanation we have is that in fact we witnessed the aftermath of an infrequent cataclysmic event between large asteroid-sized bodies, marking a complete shift in our understanding of this star system.”
The new data suggests that dust scattered outward by radiation from the system’s central star is no longer detectable, Chen said. Initially, dust near the star heated up and emitted thermal radiation identified by Spitzer’s instruments. Now, the dust that has cooled as it moves away from the star no longer emits these thermal characteristics.
Disappearing dust phenomenon
When Spitzer collected the previous data, scientists assumed that something like small ground-up bodies would stir up and replenish the dust regularly over time. But Webb’s new observations show that the dust is gone and not replaced. The amount of dust kicked up is about 100,000 times greater than that of the asteroid that killed the dinosaurs, Chen said.
Beta Pictoris, located about 63 light years from Earth, has long been a focal point for astronomers due to its proximity and its random processes where collisions, space weathering and other planet-creating factors will dictate the fate of the system.
Beta Pictoris: a young star system
At just 20 million years old – compared to our 4.5 billion year old solar system – Beta Pictoris is at a key age where giant planets have formed but terrestrial planets could still develop. It has at least two known gas giants, Beta Pic b and c, which also influence surrounding dust and debris.
“The question we are trying to contextualize is whether this whole process of forming terrestrial and giant planets is common or rare, and the even more fundamental question: are planetary systems like the solar system so rare? said co-author Kadin Worthen, a doctoral student in astrophysics at Johns Hopkins. “We’re basically trying to figure out how weird or average we are.”
Unparalleled capability of the Webb telescope
The new findings also highlight the Webb telescope’s unparalleled ability to unveil the intricacies of exoplanets and star systems, the team reports. They offer key clues about how the architectures of other solar systems resemble ours and will likely allow scientists to better understand how early disturbances influence planets’ atmospheres, their water content and other key aspects of habitability.
“Most of the JWST discoveries come from things the telescope detected directly,” said co-author Cicero Lu, a former doctoral student in astrophysics at Johns Hopkins. “In this case, the story is a little different because our results come from what JWST did not see.”
Collaborative research and funding
Other authors are Yiwei Chai and Alexis Li of Johns Hopkins; David R. Law, BA Sargent, GC Sloan, Julien H. Girard, Dean C. Hines, Marshall Perrin and Laurent Pueyo of the Space Telescope Science Institute; Carey M. Lisse of the Johns Hopkins University Applied Physics Laboratory; Dan M. Watson of the University of Rochester; Jens Kammerer of the European Southern Observatory; Isabel Rebollido of the
” data-gt-translate-attributes=”({“attribute”:”data-cmtooltip”, “format”:”html”})” tabindex=”0″ role=”link”>European Space Agency; and Christopher Stark of
” data-gt-translate-attributes=”({“attribute”:”data-cmtooltip”, “format”:”html”})” tabindex=”0″ role=”link”>NASA Goddard Space Flight Center.
The research was supported by the National Aeronautics and Space Administration under Grant No. 80NSSC22K1752.