Active Asteroids is a NASA partner citizen science project that successfully discovered active asteroids, including main-belt comets, quasi-Hilda objects, and Jupiter family comets. The project is hosted on the Zooniverse platform and is funded by a NSF Graduate Research Fellowship Program. It uses images from the Dark Energy Camera (DECam) to search for tails around asteroids and other minor planets. The research team is led by Colin Orion Chandler. As of April 2024 about 8300 volunteers carried out 6.7 million classifications of 430 thousand images. At the time only 60 active asteroids were known and 16 new active objects were discovered by this project, significantly increasing the sample of known objects.
The success of the project did result in the development of Rubin Comet Catchers, a citizen science project using data by the Vera C. Rubin Observatory and a similar approach as the Active Asteroids project.
Pre-launch preparation Before the team launched the project, the team gained experience with DECam and published three papers. These include detection of activity around previously known active asteroid (62412) , revealing 6 years of activity on 6478 Gault and activity discovered on the centaur 2014 OG392.
Discoveries
The project uses a pipeline called HARVEST, which compares metadata from astronomical image archives with the data from the Minor Planet Center and produces images at positions of minor planets. It also excludes images with no detection or images that cannot detect asteroids. Since February 2024 the team also used a Convolutional Neural Network (CNN), called TailNet, to filter out bad images before they are shown to volunteers and to identify high-likely candidates. This CNN uses classification-labels made by the volunteers and is constantly improved with new classifications. One of the first discovery was made in September 2022, when the team published a paper describing that 282P/(323137) 2003 BM80 showed sustained activity over 15 months in 2021–2022. Activity was previously reported in 2012–2013 and the team analysed the orbit, finding that it is an outbursting quasi-Hilda object. The object 2010 LH15 was discovered to have cometary activity from DECam images by the Active Asteroids project. A follow-up study did find activity in images of the Zwicky Transient Facility and showed that the object had a radius of . The study also showed that the activity was likely due to sublimation. The activity did onset at 1.86 astronomical units (AU), which is closer than other main-belt comets. The researchers find that sublimating volatiles must be buried deeper than on other active asteroids showing sublimation.
List of discoveries +Namefamilytype of activityyear-month of discoveryReferencePrevious discovery of activity2015 TC1Jupiter-family comet2022-01no2017 QN84Jupiter-family cometrecurrently active, volatile sublimation2022-01no282Pquasi-Hilda object (former Centaur or Jupiter-family comet)volatile sublimation2013-06/2022-09yes, Bolin et al.2015 FW412main-belt comet candidatesublimation2023-02no2015 VA108main-belt comet candidatevolatile sublimation2023-02no2009 DQ118quasi-Hilda object (former Jupiter family comet or Centaur)sublimation of volatile ices2023-03no2010 LH15 (aka 2010 TJ175)main-belt cometlikely sublimation2023-03no(588045) 2007 FZ18main-belt comet candidatetwo tails2023-05no2018 CZ16quasi-Hilda objectthermally driven activity indicative of water-ice sublimation2023-05no484P/SpacewatchJupiter-family comet2021-04/2023-07yes, Cheng et al.2004 CV50quasi-Hilda object2023-11no(551023) 2012 UQ192Jupiter-family Cometrecurrently active, sublimation2023-12no2019 OE31vacationing Centaurvolatile sublimation2023-12no2008 QZ44Jupiter-family comet2023-12no2018 VL10Jupiter-family comet (Mars crossing)2023-12no2018 ORJupiter-family comet (Mars crossing)2024-01no(410590) 2008 GB140main-belt comet candidate2024-02TailNet identified activityno2016 UU121main-belt comet candidate2024-02TailNet identified activityno2011 UG104Jupiter-family comet2024-05TailNet identified activityno2015 VP51Jupiter-family cometsuspected sublimation2024-09TailNet filtered, identified by citizen scientistsno2010 MK43 (aka 2010 RA78)Jupiter-family comet (former quasi-Hilda object)2024-09TailNet filtered, identified by citizen scientistsno(523822) 2012 DG61Near-Earth Comet and Apollo asteroidrecurrently active, likely sublimation2018-05/2025-01TailNet identified activitypreviously observed by G. Borisov
See also other citizen science projects researching minor planets: The Daily Minor Planet Active Asteroid Zoo inactive Stardust@home Catalina Outer Solar System Survey inactive other citizen science projects Zooniverse citizen science platform BOINC volunteer computing platform Planet Hunters: exoplanet discovery project Backyard Worlds: brown dwarf discovery project
References