Community Scientists Find 1700 Asteroids

Community scientists identified more than 1,000 possible trails of asteroids in Hubble images, leading to the discovery of 1,701 trails in all.

Beth Johnson
2 min readMay 30, 2022
IMAGE: This mosaic consists of 16 different data sets from the NASA/ESA Hubble Space Telescope that were studied as part of the Asteroid Hunter citizen community science project. Each of these datasets was assigned a colour based on the time sequence of exposures, such that the blue tones represent the first exposure in which the asteroid was captured and the red tones represent the last. CREDIT: ESA/Hubble & NASA, S. Kruk (ESA/ESTEC), Hubble Asteroid Hunter citizen science team, M. Zamani (ESA/Hubble)

One of the core pillars of CosmoQuest is community, and within that pillar, we try to bring together community members and science projects. That’s a big reason why we’re going to, spoiler alert, take off a chunk of this summer — we want to bring community science back to CosmoQuest.

In the meantime, we can share results from others working with their communities to do amazing science, such as this first story that looks at results from the Hubble Asteroid Hunter project. Those results were published in the journal Astronomy & Astrophysics, and they detail the finding of asteroid trails in images taken by the Hubble Space Telescope.

Now, some of you are wondering how they used the Hubble, that glorious workhorse telescope that brought us several deep field looks at our universe, to find asteroids close to home. Here’s a quick summary: The project involved over 11,400 community astronomers looking at more than 37,000 composite images taken by Hubble from April 2002 to March 2021. The astronomers set out to identify asteroids based on their light trails, which appeared as streaks or curved lines in the images. From that run of images, the community identified more than 1,000 possible trails of asteroids, and those detections were used to train a machine-learning algorithm.

Overall, 1,701 light trails were discovered in 1,316 Hubble images. Of those roughly 1700 potential objects, a third were attributed by the Minor Planet Center to known asteroids, leaving over 1,000 small, faint potential asteroids. Most are allocated in the main asteroid belt between Mars and Jupiter.

These trails can now be used to calculate orbits, size, and even rotation periods, despite the fact that many can no longer be found with Hubble as too much time has passed between image collection and identification. With a little maths, however, even that is a problem that can be solved.

It really is fantastic what community scientists can do.

More Information

ESA Hubble press release

Max Planck Institute press release

Hubble Asteroid Hunter — I. Identifying asteroid trails in Hubble Space Telescope images,” Sandor Kruk et al., 2022 May 6, Astronomy & Astrophysics

This story was written for the Daily Space podcast/YouTube series. Want more news from myself, Dr. Pamela Gay, and Erik Madaus? Check out

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Beth Johnson

Planetary scientist, podcast host. Communication specialist for SETI Institute and Planetary Science Institute. Buy me a coffee: