Astronomers observed a giant asteroid impact in Beta Pictoris, using data from the Webb and Spitzer telescopes. The event, which occurred 20 years ago, provides new insights into early planetary formation in this young star system. (Artist’s concept.) Credit: NASA
The new observations shed light on the unstable processes that form star systems like our own, providing a unique look at the early stages of planetary formation.
Astronomers have captured a snapshot of a giant asteroid impact in Beta Pictoris, revealing insights into early planetary formation. The study, using data from the James Webb and Spitzer space telescopes, tracked changes in dust around the star. The findings suggest a massive collision 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 collision of giant asteroids in Beta Pictoris, a neighboring star system known for its early age and turbulent planet-forming activity.
The observations highlight the unstable processes that form star systems like our own, providing a unique look at the early stages of planetary formation.
“Beta Pictoris is at an age when planet formation in the terrestrial planet zone is still ongoing through giant asteroid collisions, so what we can see here is basically how rocky planets and other bodies are forming over time. real,” said Christine Chen, a. Johns Hopkins University astronomer who led the research.
The observations were presented June 10 at the 244th Meeting of the American Astronomical Society in Madison, Wisconsin.
Two different space telescopes took pictures 20 years apart of the same area around the star called Beta Pictoris. Scientists theorize that the massive amount of dust seen in the 2004–05 Spitzer Space Telescope image indicates an asteroid impact that had largely cleared 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 noticed significant changes in the energy signatures emitted by dust grains around Beta Pictoris by comparing new data from The James Webb Space Telescope with observations from the Spitzer Space Telescope from 2004 and 2005. With Webb’s detailed measurements, the team tracked the composition and size of dust particles in the exact area previously analyzed by Spitzer.
Focusing on 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 seen earlier in 2004-05. 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.
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 studying planetary formation. The system hosts a prominent debris disk, indicative of ongoing planet formation, and has at least two known gas giants, Beta Pictoris b and c. Dynamical processes within Beta Pictoris, including frequent collisions and space weathering, provide valuable insights into the early stages of planetary development and the formation of terrestrial planets.
Evidence for a cataclysmic collision
“We think all that dust is what we first saw in the Spitzer data from 2004 and 2005,” said Chen, who is also an astronomer at the Space Telescope Science Institute. “With the new Webb data, the best explanation we have is that we actually witnessed the aftermath of a rare, cataclysmic event between large asteroid-sized bodies, marking a complete shift in understanding ours for this star system.”
The new data suggest that dust that was blown away by radiation from the system’s central star is no longer detectable, Chen said. First, the dust near the star heated up and emitted thermal radiation that Spitzer’s instruments detected. Now, the dust that cooled as it moved far away from the star no longer emits those thermal characteristics.
The phenomenon of dust disappearance
When Spitzer collected the previous data, scientists assumed that something like the small grinding bodies would stir up and replenish dust steadily over time. But Webb’s new observations show that the dust disappeared and was not replaced. The amount of dust ejected is about 100,000 times larger than 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 because of its proximity and the random processes where collisions, space weather and other planet-forming factors will dictate the fate of the system.
Beta Pictoris: A Young Star System
At just 20 million years – compared to our solar system’s 4.5 billion years – Beta Pictoris is in a key age where giant planets have formed, but terrestrial planets may still be developing. It has at least two known gas giants, Beta Pic b and c, which also influence the surrounding dust and debris.
“The question we’re trying to contextualize is whether the entire formation process of terrestrial and giant planets is common or rare, and the even more fundamental question: Are planetary systems like the solar system that 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.”
The unmatched capability of the Webb telescope
The new insights also underscore the Webb telescope’s unmatched ability to reveal the intricacies of exoplanets and star systems, the team reports. They provide key clues about how the architectures of other solar systems resemble ours and are likely to deepen scientists’ understanding of how early perturbations affect the planets’ atmospheres, water content and other key aspects of habitability.
“Most of the discoveries from JWST come from things the telescope has detected 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 come from what JWST didn’t 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 e European Space Agency; and Christopher Stark of NASA Goddard Space Flight Center.
The research was supported by the National Aeronautics and Space Administration under Grant no. 80NSSC22K1752.