Active asteroid
Active asteroids are
The first active asteroid discovered is 7968 Elst–Pizarro. It was discovered (as an asteroid) in 1979 but then was found to have a tail by Eric Elst and Guido Pizarro in 1996 and given the cometary designation 133P/Elst-Pizarro.[2][6]
Orbits
Unlike
- semi-major axis a < aJupiter (5.20 AU)
- Tisserand parameterwith respect to Jupiter TJ > 3.08
Jewitt chooses 3.08 as the Tisserand parameter to separate asteroids and comets instead of 3.0 (the Tisserand parameter of Jupiter itself) to avoid ambiguous cases caused by the real
The first three identified active asteroids all orbit within the outer part of the asteroid belt.[7]
Activity
Some active asteroids display a cometary dust tail only for a part of their orbit near
When discovered in January 2010,
P/2013 R3
P/2013 R3 (Catalina–PanSTARRS) was discovered independently by two observers by
Dimorphos
By smashing into the asteroid moon of the binary asteroid 65803 Didymos, NASA's Double Asteroid Redirection Test spacecraft made Dimorphos an active asteroid. Scientists had proposed that some active asteroids are the result of impact events, but no one had ever observed the activation of an asteroid. The DART mission activated Dimorphos under precisely known and carefully observed impact conditions, enabling the detailed study of the formation of an active asteroid for the first time.[17][18] Observations show that Dimorphos lost approximately 1 million kilograms after the collision.[19] Impact produced a dust plume that temporarily brightened the Didymos system and developed a 10,000-kilometer (6,200 mi)-long dust tail that persisted for several months.[20][21][22] The DART impact is predicted to have caused global resurfacing and deformation of Dimorphos's shape, leaving an impact crater several tens of meters in diameter.[23][24][25] The impact has likely sent Dimorphos into a chaotically tumbling rotation that will subject the moon to irregular tidal forces by Didymos before it will eventually return to a tidally locked state within several decades.[26][27][28]
Composition
Some active asteroids show signs that they are icy in composition like a traditional comet, while others are known to be rocky like an asteroid. It has been hypothesized that main-belt comets may have been the source of Earth's water, because the deuterium–hydrogen ratio of Earth's oceans is too low for classical comets to have been the principal source.[29] European scientists have proposed a sample-return mission from a MBC called Caroline to analyse the content of volatiles and collect dust samples.[10]
List
Identified members of this morphology class (TJup>3.08) include:[30]: 17
Name | Semi-major axis )
(AU |
Perihelion (AU) |
Eccentricity | TJup | Orbital class |
Diameter (km) |
Rotation (hr)
period |
Cause | Activity discovery year |
Recurrent? |
---|---|---|---|---|---|---|---|---|---|---|
1 Ceres | 2.766 | 2.550 | 0.078 | 3.310 | main-belt (middle) | 939.4 | 9.07 | Water sublimation[3] | 2014 | |
493 Griseldis | 3.116 | 2.568 | 0.176 | 3.140 | main-belt (outer) | 41.56 | 51.94 | Impact[31] | 2015 | ✗ |
596 Scheila | 2.929 | 2.45 | 0.163 | 3.209 | main-belt (outer) | 159.72 | 15.85 | Impact[32][33][34] | 2011 | ✗ |
2201 Oljato | 2.174 | 0.624 | 0.713 | 3.299 | NEO (Apollo) | 1.8 | >26 | Sublimation[35] | 1984 | ✗ |
3200 Phaethon | 1.271 | 0.140 | 0.890 | 4.510 | NEO (Apollo) | 6.26 | 3.60 | Thermal fracturing, dehydration cracking, and/or rotational disintegration[36] | 2010 | ✓ |
6478 Gault | 2.305 | 1.860 | 0.193 | 3.461 | main-belt (inner) | 5.6 | 2.49 | Rotational disintegration[37][38][39] | 2019 | ✓ |
(62412) 2000 SY178 | 3.159 | 2.909 | 0.079 | 3.197 | main-belt (outer) | 10.38 | 3.33 | Rotational disintegration[40] | 2014 | ✗ |
65803 Didymos/Dimorphos | 1.643 | 1.013 | 0.383 | 4.204 | NEO (Apollo) | 0.77 / 0.15 | 2.26 | Human-caused impact | 2022 | ✗ |
101955 Bennu | 1.126 | 0.896 | 0.204 | 5.525 | NEO (Apollo) | 0.48 | 4.29 | (unknown)[30]: 22 Electrostatic lofting, impacts, thermal fracturing, or dehydration cracking |
2019 | ✓ |
(588045) 2007 FZ18 | 3.176 | 2.783 | 0.124 | 3.188 | main-belt (outer) | 2023 | ||||
2002 CW116 | 2.690 | 2.068 | 0.231 | 3.319 | main-belt (middle) | 0.5 | 2024 | |||
2008 BJ22 | 3.071 | 2.943 | 0.042 | 3.199 | main-belt (outer) | <0.4 | 2022 | ✗ | ||
2010 LH15 | 2.744 | 1.770 | 0.355 | 3.230 | main-belt (middle) | 1.483 | 2023 | ✓ | ||
2015 BC566 | 3.062 | 2.957 | 0.034 | 3.201 | main-belt (outer) | 2023 | ✗ | |||
2015 FW412 | 2.765 | 2.319 | 0.161 | 3.280 | main-belt (middle) | 2023 | ||||
2015 VA108 | 3.128 | 2.451 | 0.217 | 3.160 | main-belt (outer) | 2023 | ||||
2023 JN16 | 2.696 | 2.300 | 0.147 | 3.351 | main-belt (middle) | 2023 | ||||
107P/4015 Wilson–Harrington | 2.625 | 0.966 | 0.632 | 3.082 | NEO (Apollo) | 6.92 | 7.15 | Sublimation[41][42] | 1949 | ✗ |
133P/7968 Elst–Pizarro | 3.165 | 2.668 | 0.157 | 3.184 | main-belt (outer) | 3.8 | 3.47 | Sublimation/rotational disintegration[43][44] | 1996 | ✓ |
176P/118401 LINEAR | 3.194 | 2.578 | 0.193 | 3.167 | main-belt (outer) | 4.0 | 22.23 | Sublimation[45] | 2005 | ✗ |
233P/La Sagra (P/2009 WJ50)
|
3.033 | 1.786 | 0.411 | 3.081 | main-belt (outer) | 3.0 | 2010 | ✗ | ||
238P/Read (P/2005 U1) | 3.162 | 2.362 | 0.253 | 3.153 | main-belt (outer) | 0.8 | Sublimation[46] | 2005 | ✓ | |
259P/Garradd (P/2008 R1)
|
2.727 | 1.794 | 0.342 | 3.217 | main-belt (middle) | 0.60 | Sublimation[47] | 2008 | ✓ | |
288P/(300163) 2006 VW139 | 3.051 | 2.438 | 0.201 | 3.203 | main-belt (outer) | 1.8 / 1.2 | Sublimation[48] | 2011 | ✓ | |
311P/PanSTARRS (P/2013 P5) | 2.189 | 1.935 | 0.116 | 3.660 | main-belt (inner) | 0.4 | >5.4 | Rotational disintegration[49][50][51] | 2013 | ✓ |
313P/Gibbs (P/2003 S10)
|
3.154 | 2.391 | 0.242 | 3.133 | main-belt (outer) | 2.0 | Sublimation[52] | 2003 | ✓ | |
324P/La Sagra (P/2010 R2) | 3.098 | 2.621 | 0.154 | 3.099 | main-belt (outer) | 1.1 | Sublimation[53] | 2010 | ✓ | |
331P/Gibbs (P/2012 F5) | 3.005 | 2.879 | 0.042 | 3.228 | main-belt (outer) | 3.54 | 3.24 | Rotational disintegration[54][55] | 2012 | ✗ |
354P/LINEAR (P/2010 A2) | 2.290 | 2.004 | 0.125 | 3.583 | main-belt (inner) | 0.12 | 11.36 | Impact[56] | 2010 | ✗ |
358P/PanSTARRS (P/2012 T1) | 3.155 | 2.410 | 0.236 | 3.134 | main-belt (outer) | 0.64 | Sublimation[57] | 2012 | ✗ | |
426P/PanSTARRS (P/2019 A7) | 3.188 | 2.675 | 0.161 | 3.103 | main-belt (outer) | 2.4 | 2019 | ✗ | ||
427P/ATLAS (P/2017 S5) | 3.171 | 2.178 | 0.313 | 3.092 | main-belt (outer) | 0.90 | 1.4 | Sublimation/rotational disintegration[58] | 2017 | ✗ |
432P/PanSTARRS (P/2021 N4) | 3.045 | 2.302 | 0.244 | 3.170 | main-belt (outer) | <1.4 | 2021 | ✗ | ||
433P/(248370) 2005 QN173 | 3.067 | 2.374 | 0.226 | 3.192 | main-belt (outer) | 3.2 | Sublimation/rotational disintegration | 2021 | ✓ | |
435P/PanSTARRS (P/2021 T3) | 3.018 | 2.056 | 0.319 | 3.090 | main-belt (outer) | 2021 | ✗ | |||
455P/PanSTARRS (P/2021 S9) | 3.156 | 2.193 | 0.305 | 3.087 | main-belt (outer) | <1.6 | 2017 | ✗ | ||
456P/PanSTARRS (P/2021 L4) | 3.165 | 2.788 | 0.119 | 3.125 | main-belt (outer) | <4.4 | 2021 | ✗ | ||
457P/2020 O1 (Lemmon–PanSTARRS) | 2.647 | 2.329 | 0.120 | 3.376 | main-belt (middle) | 0.84 | 1.67 | Sublimation/rotational disintegration[59] | 2020 | ✓ |
P/2013 R3 (Catalina–PanSTARRS) | 3.033 | 2.205 | 0.273 | 3.184 | main-belt (outer) | ~0.4 | Sublimation/rotational disintegration[60] | 2013 | ✗ | |
P/2015 X6 (PanSTARRS) | 2.755 | 2.287 | 0.170 | 3.318 | main-belt (middle) | <1.4 | Sublimation[61] | 2015 | ✗ | |
P/2016 G1 (PanSTARRS) | 2.583 | 2.041 | 0.210 | 3.367 | main-belt (middle) | <0.8 | Impact[62] | 2016 | ✗ | |
P/2016 J1-A/B (PanSTARRS) | 3.172 | 2.449 | 0.228 | 3.113 | main-belt (outer) | <1.8 / <0.8 | Sublimation[63] | 2016 | ✓ | |
P/2018 P3 (PanSTARRS) | 3.007 | 1.756 | 0.416 | 3.096 | main-belt (outer) | <1.2 | Sublimation | 2018 | ✓ | |
P/2019 A3 (PanSTARRS) | 3.147 | 2.313 | 0.265 | 3.099 | main-belt (outer) | <0.8 | 2019 | ✗ | ||
P/2019 A4 (PanSTARRS) | 2.614 | 2.379 | 0.090 | 3.365 | main-belt (middle) | 0.34 | 2019 | ✗ | ||
P/2021 A5 (PanSTARRS) | 3.047 | 2.620 | 0.140 | 3.147 | main-belt (outer) | 0.30 | Sublimation | 2021 | ✗ | |
P/2021 R8 (Sheppard) | 3.019 | 2.131 | 0.294 | 3.179 | main-belt (outer) | 2021 | ✗ | |||
P/2022 R5 (PanSTARRS) | 3.071 | 2.470 | 0.196 | 3.148 | main-belt (outer) | 2022 | ||||
P/2023 S4 (Hogan) | 3.134 | 2.542 | 0.189 | 3.185 | main-belt (outer) | 2023 |
Exploration
On January 6, 2019, the OSIRIS-REx mission first observed episodes of particle ejection from 101955 Bennu shortly after entering orbit around the near-Earth asteroid, leading it to be newly classified as an active asteroid and marking the first time that asteroid activity had been observed up close by a spacecraft. It has since observed at least 10 other such events.[4] The scale of these observed mass loss events is much smaller than those previously observed at other active asteroids by telescopes, indicating that there is a continuum of mass loss event magnitudes at active asteroids.[65]
See also
- Centaur (minor planet)
- Extinct comet
References
- ^ Andrews, Robin George (18 November 2022). "The Mysterious Comets That Hide in the Asteroid Belt - Comets normally fly in from the far reaches of space. Yet astronomers have found them seemingly misplaced in the asteroid belt. Why are they there?". The New York Times. Retrieved 18 November 2022.
- ^ UCLA, Department of Earth and Space Sciences. Retrieved 2020-01-26.
- ^ S2CID 119209764. Retrieved 2020-01-30.
- ^ a b Chang, Kenneth; Stirone, Shannon (19 March 2019). "The Asteroid Was Shooting Rocks Into Space. 'Were We Safe in Orbit?' - NASA's Osiris-Rex and Japan's Hayabusa2 spacecraft reached the space rocks they are surveying last year, and scientists from both teams announced early findings on Tuesday (03/19/2019)". The New York Times. Retrieved 21 March 2019.
- ^ "Hubble Observes Six Tails from an Unusual Asteroid". Space Telescope Science Institute (STScI), official YouTube channel for the Hubble Space Telescope. Archived from the original on 2021-12-22. Retrieved 2014-11-15.
- ^ Hsieh, Henry (January 20, 2004). "133P/Elst-Pizarro". UH Institute for Astronomy. Archived from the original on 26 October 2011. Retrieved 22 June 2012.
- ^ a b c d Henry H. Hsieh (May 2010). "Main Belt Comets". Hawaii. Archived from the original on 2011-08-06. Retrieved 2010-12-15. (older 2010 site) Archived 2009-08-10 at the Wayback Machine
- ^ Harrington, J.D.; Villard, Ray (6 March 2014). "RELEASE 14-060 NASA's Hubble Telescope Witnesses Asteroid's Mysterious Disintegration". NASA. Retrieved 6 March 2014.
- ^ "Hubble witnesses an asteroid mysteriously disintegrating". ESA / HUBBLE. Retrieved 12 March 2014.
- ^
- ^ MPEC 2010-A51 : COMET P/2010 A2 (LINEAR)
- S2CID 205222567.
- S2CID 4330570.
- Bibcode:2013CBET.3658....1H. Retrieved 27 September 2013.
- ^ a b Licandro, Javier. "Main Belt Comet P/2013 R3 is breaking apart". IAC Press Release. Retrieved 17 October 2013.
- ^ a b "Hubble Witnesses Asteroid's Mysterious Disintegration | Science Mission Directorate".
- ^ Furfaro, Emily (28 February 2023). "NASA's DART Data Validates Kinetic Impact as Planetary Defense Method". NASA. Retrieved 9 March 2023. This article incorporates text from this source, which is in the public domain.
- S2CID 257282549.
- S2CID 257282080. Retrieved 9 March 2023.
- ^ Blue, Charles (3 October 2022). "SOAR Telescope Catches Dimorphos's Expanding Comet-like Tail After DART Impact". NOIRLab. Retrieved 4 February 2023.
- ^ Merzdorf, Jessica (15 December 2022). "Early Results from NASA's DART Mission". NASA. Retrieved 4 February 2023.
- S2CID 257282549.
- S2CID 249268810. 128.
- S2CID 250327233. 148.
- ^ Raducan, S. D.; Jutzi, M.; Zhang, Y.; Cheng, A. F.; Collins, G. S.; Davison, T. M.; et al. (March 2023). Low Strength of Asteroid Dimorphos As Demonstrated by the Dart Impact (PDF). 54th Lunar and Planetary Science Conference 2023. Lunar and Planetary Institute. Retrieved 4 February 2023.
- S2CID 236033921. 114624.
- S2CID 249268465. 157.
- ^ Meyer, A. J.; Noiset, G.; Karatekin, Ö.; McMahon, J.; Agrusa, H. F.; Nakano, R.; et al. (March 2023). Tidal Dissipation in Didymos Following the DART Impact (PDF). 54th Lunar and Planetary Science Conference 2023. Lunar and Planetary Institute. Retrieved 4 February 2023.
- ^ Main-Belt Comets May Have Been Source Of Earths Water, Space Daily, Mar 23, (2006).
- ^ Bibcode:2022arXiv220301397J.
- Bibcode:2015DPS....4741403T.
- S2CID 54187826.
- ISSN 2041-8205.
- S2CID 15039916.
- S2CID 10618035.
- S2CID 37387069.
- S2CID 85544222.
- S2CID 196831757.
- ISSN 2041-8213.
- S2CID 56464879.
- S2CID 118530975.
- .
- ISSN 0004-6256.
- ISSN 0004-6256.
- ISSN 0004-6256.
- ISSN 2041-8205.
- ISSN 0004-6256.
- S2CID 4469577.
- ISSN 2041-8205.
- S2CID 119298012.
- ISSN 0004-6361.
- S2CID 44820411.
- S2CID 119293534.
- ISSN 0004-637X.
- ISSN 2041-8213.
- S2CID 37325835.
- S2CID 166874.
- S2CID 119508428.
- S2CID 249674510. L15.
- S2CID 54680553.
- S2CID 118558049.
- ISSN 2041-8213.
- S2CID 118824144.
- ^ S2CID 55821241.
- S2CID 208764910.
External links
- Proper elements of active asteroids at Asteroid Families Portal
- Henry Hsieh's Main-Belt Comets page has extensive details on Main-belt comets
- David Jewitt. The Active Asteroids
- Planetary Society article on MBCs
- Discussion of possible differences in characteristics of the water in MBCs and other comets
- YouTube Interview with David Jewitt (discussion on main-belt comets starts around 9 minutes into video)
- Impact trigger mechanism diagram by David Jewitt
- Comet-like appearance of (596) Scheila
- Project T3: Finding Comets in the Asteroid Population
- Jewitt, David (2012). "The Active Asteroids". The Astronomical Journal. 143 (3): 66. S2CID 45208650.
- Hsieh, Henry H.; Yang, Bin; Haghighipour, Nader; Kaluna, Heather M.; Fitzsimmons, Alan; Denneau, Larry; Novaković, Bojan; Jedicke, Robert; Wainscoat, Richard J.; Armstrong, James D.; Duddy, Samuel R.; Lowry, Stephen C.; Trujillo, Chadwick A.; Micheli, Marco; Keane, Jacqueline V.; Urban, Laurie; Riesen, Timm; Meech, Karen J.; Abe, Shinsuke; Cheng, Yu-Chi; Chen, Wen-Ping; Granvik, Mikael; Grav, Tommy; S2CID 8693844.
- New Comet: P/2012 T1 (PANSTARRS) (Remanzacco Observatory : 16 Oct 2012)
- Ferrín, Ignacio; Zuluaga, Jorge; Cuartas, Pablo (2013). "The location of Asteroidal Belt Comets (ABCs), in a comet's evolutionary diagram: The Lazarus Comets". Monthly Notices of the Royal Astronomical Society. 434 (3): 1821–1837. S2CID 118177774.
- P/2013 R3: a Main Belt Comet that is breaking apart. J. Licandro New images obtained with the GTC