11,400 ‘Citizen Scientists’ Help Discover 1,031 New Asteroids After Search Of Old Hubble Images

by techlowdown · 6 May 2022

So-called “citizen science” initiatives are a powerful tool for astronomers looking for help to process huge datasets—and the Hubble Space Telescope makes a fine asteroid hunter.

They’re the two takeaways from the conclusion of Hubble Asteroid Hunter, a citizen science project to identify asteroids in 20 years of old data that has unearthed a whopping 1,701 asteroid trails.

Exactly 1,031 are new and previously unknown to astronomers—most of them faint and likely to be smaller asteroids than those detected in ground-based surveys.

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 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.

ESA/Hubble & NASA, S. Kruk (ESA/

The project, which today published its results in Astronomy & Astrophysics, had volunteers—members of the public keen to help out—sift through 37,000 images on the lookout for asteroids accidentally captured in Hubble’s images. The space telescope typically studies a particular object or area of the sky for about 30 minutes, with asteroid trails appearing as curved lines or streaks in these images.

Launched by the European Science and Technology Centre (ESTEC) and the European Space Astronomy Centre’s Science Data Centre (ESDC), the project had two ways of finding the asteroid trails:

Human intelligence: the over 11,400 members of the Zooniverse platform, the world’s largest and most popular citizen science platform, who classified and analysed the images.
Artificial intelligence: an automated deep learning algorithm built with Google Cloud AutoML Vision.

The search also unearthed new galaxies and nebulae.

Some asteroids from within our Solar System have photobombed deep images of the Universe taken by … [+] the NASA/ESA Hubble Space Telescope. These asteroids reside, on average, only about 260 million kilometres from Earth — right around the corner in astronomical terms. Yet they’ve horned their way into this picture of thousands of galaxies scattered across space and time at inconceivably farther distances. This Hubble photo of a random patch of sky is part of the Frontier Fields survey. The colourful image contains thousands of galaxies, including massive yellowish ellipticals and majestic blue spirals. Much smaller, fragmentary blue galaxies are sprinkled throughout the field. The reddest objects are most likely the farthest galaxies, whose light has been stretched into the red part of the spectrum by the expansion of space. Intruding across the picture are asteroid trails that appear as curved or S-shaped streaks. Rather than leaving one long trail, the asteroids appear in multiple Hubble exposures that have been combined into one image. Of the 20 total asteroid sightings for this field, seven are unique objects. Of these seven asteroids, only two were earlier identified. The others were too faint to be seen previously. The trails look curved due to an observational effect called parallax. As Hubble orbits around Earth, an asteroid will appear to move along an arc with respect to the vastly more distant background stars and galaxies. The motion of Earth around the Sun, and the motion of the asteroids along their orbits, are other contributing factors to the apparent skewing of asteroid paths. All the asteroids were found manually, the majority by “blinking” consecutive exposures to capture apparent asteroid motion. Astronomers found a unique asteroid for every 10 to 20 hours of exposure time. The Frontier Fields program is a collaboration among several space telescopes and ground-based observatories to study six massive galaxy clusters and their effects. Using a diff

NASA, ESA, and B. Sunnquist and

Most of the 1,031 newly discovered asteroids are expected to be located in the Main Asteroid Belt between Mars and Jupiter, which hasn’t been studied much.

Work will now begin to take each of the 1,031 new asteroids and explore their orbits, their sizes and how quickly they rotate.

However, since the asteroids are faint and they were captured in old images it’s unlikely that scientists can piece together enough information about them to have Hubble capture them once again in its tight field of view.

Wishing you clear skies and wide eyes.