Hubble discovers new small asteroids in main belt survey

Hubble discovers new small asteroids in main belt survey
by Erica Marchand
Paris, France (SPX) Apr 22, 2024
Using a vast archive of NASA/ESA Hubble Space Telescope images, astronomers have identified a previously unseen group of small main-belt asteroids. This discovery involved analyzing over 37,000 images collected by Hubble over 19 years, leading to the detection of 1,701 asteroid trails, 1,031 of which had not been cataloged previously. Notably, around 400 of these are smaller than one kilometer in diameter.

Contributions from 'citizen scientists' worldwide and the use of machine learning algorithms were crucial in identifying these asteroids. This innovative method could be adapted for other long-term astronomical data, researchers suggest.

"We're seeing deeper into the less observed small main-belt asteroids. This large, random sample of asteroid trails reveals more about our Solar System's evolutionary history than we anticipated," stated Pablo Garcia Martin from the Autonomous University of Madrid. He expressed surprise at the high number of detections, which supports theories on the Solar System's evolution.

The findings suggest that many small asteroids are likely remnants of collisions between larger asteroids, akin to fragments from shattered pottery. This continual collision process has occurred over billions of years. Conversely, the hypothesis that these small bodies could have originally formed at such diminutive sizes appears less likely, as no process would prevent them from accumulating more mass over time.

Co-author Bruno Merin of the European Space Astronomy Centre highlighted the importance of Hubble's unique orbital capabilities. "Hubble's rapid orbit allows us to capture distinct asteroid trails," he explained. These trails help determine asteroid distances and orbit shapes by comparing the trails' curvature from multiple angles.

Most of the asteroids tracked are located in the main asteroid belt between Mars and Jupiter. By assessing their brightness and distance, researchers can estimate their sizes, with the dimmest asteroids in the survey being barely detectable compared to the faintest stars visible to the naked eye.

Bruno also discussed the role of citizen science in the research. "We enlisted over 10,000 volunteers to sift through the extensive Hubble archives, an effort that was essential due to the vast amount of data and the dynamic nature of asteroid positions," he said.

The Hubble Asteroid Hunter project, launched in 2019, was a collaboration among various European scientific institutions and the Zooniverse platform. The project aims to continue analyzing asteroid trails to learn more about their physical properties, including rotation periods, although many cannot be reobserved to confirm their orbits.

Research Report:Hubble Asteroid Hunter: III. Physical properties of newly found asteroids