2020 CD3
Gemini North | |
Discovery [1][2] | |
---|---|
Discovered by | Mt. Lemmon Survey
|
main belt) | |
V[8] B–V=0.90±0.07[8] V–R=0.46±0.08 R–I=0.44±0.06 | |
>30 (current)[10] 20 (at discovery)[2] | |
31.80±0.34[6] 31.8[2] | |
2020 CD3 (also 2020CD3 or CD3 for short)
It is the second temporary satellite of Earth discovered in situ, after 2006 RH120, which was discovered in 2006. Based on its nominal trajectory, 2020 CD3 was captured by Earth around 2016–2017, and escaped Earth's gravitational sphere of influence around 7 May 2020.[5][8][13] 2020 CD3 will make another close pass to Earth in March 2044, though it will most likely not be captured by Earth due to the greater approach distance.[14][15]
2020 CD3 has an absolute magnitude around 32, indicating that it is very small in size. Assuming that 2020 CD3 has a low albedo characteristic of dark, carbonaceous C-type asteroids, its diameter is probably around 1.9–3.5 metres (6–11 ft).[16][17] 2020 CD3 is classified as an Arjuna asteroid, a subtype of small Earth-crossing Apollo asteroids that have Earth-like orbits.[5]
Discovery
2020 CD3 was discovered on 15 February 2020, by astronomers Theodore Pruyne and
The object's discovery was reported to the
Precovery images of 2020 CD3 have been identified back to May 2018.[2]
Nomenclature
Upon discovery, the asteroid was given the temporary internal designation C26FED2.
Orbit
Prior to the temporary capture of 2020 CD3, its heliocentric orbit was probably Earth-crossing, either falling into the categories of an
Temporary capture
Because 2020 CD3 has an Earth-like heliocentric orbit, its motion relative to Earth is low, allowing for it to slowly approach the planet and be captured.
2020 CD3's orbit around Earth is highly variable and eccentric, hence predictions of its past trajectory before mid-2017 are uncertain.[17][25] Due to the Yarkovsky effect on small asteroids, the first precovery image being from 2018, and numerous approaches to the Earth and Moon, it is unknown if the asteroid was closer than the Moon on Christmas Day 2015.[26]
Date | ) | NEODyS nominal geocentric distance (AU) |
Find_Orb nominal geocentric distance (AU) |
ESA NEOCCnominal geocentric distance (AU) |
MPC nominal geocentric distance (AU) |
---|---|---|---|---|---|
2015-Dec-25 | 0.0006 AU (90 thousand km) | 0.0162 AU (2.42 million km) | 0.288 AU (43.1 million km) | 0.345 AU (51.6 million km) | 0.834 AU (124.8 million km) |
Between September 2017 and February 2020 it made 12 close approaches to Earth,[14] during which time it was never more than 0.0112 AU (1.68 million km) from Earth.[27] According to the JPL Small-Body Database, on 15 September 2017 it passed 12,000 km (7,500 mi) from the Moon.[6] The closest approach to Earth occurred on 4 April 2019, when it approached to a distance of 13,104 km (8,142 mi).[6][c] The final close approach in 2020 occurred on 13 February 2020 at a distance of about 41,000 km (25,000 mi) from Earth's surface.[25] The orbital period of 2020 CD3 around Earth ranged from 70 to 90 days.[25] 2020 CD3 escaped Earth's Hill sphere at roughly 0.01 AU (1.5 million km) in March 2020[25][28] and returned to solar orbit on 7 May 2020.[5]
Epoch | Earth distance[28] | Geocentric eccentricity[13] |
Apogee[13] | Orbital period[13] |
---|---|---|---|---|
2020-May-07 | 0.0189 AU (2.83 million km) | 0.9901 | 2.25 AU (337 million km) | 693.61 years (253,341 d) |
2020-May-08 | 0.0191 AU (2.86 million km) | 1.0347 |
Being captured into a temporary orbit around Earth, 2020 CD3 is a temporarily captured object or a temporary satellite of Earth.[1][29] 2020 CD3 has also been widely referred to in the media as a "mini-moon" of Earth, due to its small size.[18][16][17][30] 2020 CD3 is the second known temporary captured object discovered in situ around Earth, with the first being 2006 RH120 discovered in 2006.[30] Other objects have also been suspected to have once been temporarily captured, including the small near-Earth asteroid 1991 VG and the bolide DN160822 03.[31][32] Objects that get temporarily captured by Earth are thought to be common, though larger objects over 0.6 m (2 ft) in diameter are believed to be less likely to be captured by Earth and detected by modern telescopes.[30]
Future approaches
2020 CD3 will continue orbiting the Sun and will approach Earth on 20 March 2044, from a distance of 0.0245 AU (3.67 million km; 2.28 million mi).
The possibility of 2020 CD3
Physical characteristics
This section needs to be updated.(August 2020) |
2020 CD3 is estimated to have an
See also
- 1991 VG – near-Earth asteroid temporarily captured by Earth after its discovery in 1991
- 2006 RH120 – the first temporary Earth satellite discovered in situ 2006
- 2022 NX1 another temporary Earth satellite discovered in 2022
- 2023 FY3 – another temporary Earth satellite discovered in 2023
- Claimed moons of Earth
- Quasi-satellite
Notes
- for constellation coordinates.
- ^ JPL Horizons 28 Feb 2020 solution[6]
- ^ 13104 km – Earth radius of 6371 km is 6733 km from the surface of Earth.
- ^ Already outside of the Earth's Hill sphere which has a radius of roughly 0.01 AU (1.5 million km).
References
- ^ a b c d e f g h "MPEC 2020-D104 : 2020 CD3: Temporarily Captured Object". Minor Planet Electronic Circular. Minor Planet Center. 25 February 2020. Retrieved 25 February 2020.
- ^ a b c d "2020 CD3". Minor Planet Center. International Astronomical Union. Retrieved 25 February 2020.
- ^ a b "2020 CD3". NEO Exchange. Las Cumbres Observatory. 15 February 2020. Retrieved 25 February 2020.
- ^ a b c d ""Pseudo-MPEC" for C26FED2". Project Pluto. 24 February 2020. Archived from the original on 25 February 2020. Retrieved 25 February 2020.
- ^ S2CID 214605877.
- ^ a b c d e f g h i "JPL Small-Body Database Browser: 2020 CD3" (2020-03-22 last obs.). Jet Propulsion Laboratory. Retrieved 25 February 2020.
- ^ "JPL Horizons On-Line Ephemeris for 2020 CD3 orbit of Earth (geocentric) at epoch 2022-Aug-09". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 21 August 2022. Geocentric solution. Ephemeris Type: Orbital Elements / Center: @399 / Time Span: 2022-Aug-09 (to match infobox epoch)
- ^ S2CID 221103592.
- ^ a b c d e f "2020 CD3 -- Earth Impact Risk Summary". Center for Near Earth Object Studies. Jet Propulsion Laboratory. Retrieved 3 March 2020.
- ^ "2020CD3". Near Earth Objects – Dynamic Site. Department of Mathematics, University of Pisa, Italy. Retrieved 25 February 2020.
- ^ a b Crewe, Ralph (24 November 2020). "Here's what we know about Earth's new minimoon". Universe Today. Retrieved 25 November 2020.
- ^ S2CID 227119071.
- ^ a b c d "JPL Horizons On-Line Ephemeris for 2020 CD3 orbit of Earth (geocentric) at epoch 2020-May-07". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Archived from the original on 8 July 2022. Retrieved 8 July 2022. Geocentric solution. Ephemeris Type: Orbital Elements / Center: @399
- ^ a b c d "2020CD3 Close Approaches". Near Earth Objects – Dynamic Site. Department of Mathematics, University of Pisa, Italy. Archived from the original on 23 October 2021. Retrieved 1 March 2020.
- ^ a b Koren, Marina (20 March 2020). "A Fleeting Moment in the Solar System". The Atlantic. Retrieved 2 April 2020.
- ^ a b Byrd, Deborah (26 February 2020). "New image of Earth's new mini-moon". EarthSky. Retrieved 26 February 2020.
- ^ a b c d Crane, Leah (26 February 2020). "Earth has acquired a brand new moon that's about the size of a car". New Scientist. Retrieved 27 February 2020.
- ^ a b c "Gemini Telescope Images "Minimoon" Orbiting Earth — in Color!". National Optical-Infrared Astronomy Research Laboratory (Press release). National Science Foundation. 27 February 2020. Retrieved 28 February 2020.
- ^ "2020 CD3 Ephemerides". Near Earth Objects – Dynamic Site (Ephemerides at discovery). Department of Mathematics, University of Pisa, Italy. Retrieved 28 February 2020.
- ^ a b c King, Bob (2 March 2020). "Earth Has A Mini-Moon — But Not for Long!". Sky & Telescope. Retrieved 3 March 2020.
- ^ a b c Howell, Elizabeth (28 February 2020). "How scientists found Earth's new minimoon and why it won't stay here forever". Space.com. Retrieved 29 February 2020.
- ^ "How Are Minor Planets Named?". Minor Planet Center. International Astronomical Union. Retrieved 29 February 2020.
- ^ a b Plait, Phil (27 February 2020). "The Earth has a new minimoon! But not for long..." Bad Astronomy. Syfy Wire. Retrieved 29 February 2020.
- S2CID 119251954.
- ^ a b c d e Naidu, Shantanu; Farnocchia, Davide. "Tiny Object Discovered in Distant Orbit Around the Earth". Center for Near Earth Object Studies. Jet Propulsion Laboratory. Retrieved 3 March 2020.
- ^ a b "Horizons Batch for Christmas 2015 Geocentric distance" (Nominal is 0.0006 AU (90,000km)). JPL Horizons. Archived from the original on 14 July 2022. Retrieved 13 July 2022. (JPL#27/Soln.date: 2021-Jun-25) (NEODyS-2 on 25 Dec 2015) (Find_Orb on 25 Dec 2015) (ESA NEOCC on 25 Dec 2015)
- ^ "Horizons Batch for September 2017 – April 2020 Geocentric distance" (Maximum Apogee occurs 2020-Jan-05 @ 0.011179 (1.7 million km)). JPL Horizons. Archived from the original on 11 July 2022. Retrieved 11 July 2022. (JPL#27/Soln.date: 2021-Jun-25) (NEODyS-2 for 5 Jan 2020)
- ^ a b "Horizons Batch for March 2020 – May 2020 Geocentric distance" (Escaping Earth's Hill Sphere @ ~0.01au). JPL Horizons. Archived from the original on 8 July 2022. Retrieved 7 July 2022. (JPL#27/Soln.date: 2021-Jun-25)
- ^ a b Gough, Evan (27 February 2020). "Astronomers Discover a Tiny New Temporary Moon for the Earth. Welcome to the Family 2020 CD3". Universe Today. Retrieved 29 February 2020.
- ^ a b c Boyle, Rebecca (27 February 2020). "A New Mini-Moon Was Found Orbiting Earth. There Will Be More". The New York Times. Retrieved 29 February 2020.
- S2CID 189823446.
- ^ Gohd, Chelsea (2 December 2019). "Scientists Spot Rare Minimoon Fireball Over Australia". Space.com. Retrieved 29 February 2020.
- ^ "Horizons Batch for September 2082 – November 2082 Geocentric distance" (Earth approach occurs 2082-Oct-08 06:47 @ 0.002507 AU). JPL Horizons. Retrieved 10 July 2022. (JPL#27/Soln.date: 2021-Jun-25)
External links
- Earth Has A Mini-Moon — But Not for Long! by Bob King, Sky & Telescope, 2 March 2020
- A New Mini-Moon Was Found Orbiting Earth. There Will Be More. by Rebecca Boyle, The New York Times, 27 Feb 2020
- Gemini Telescope Images "Minimoon" Orbiting Earth — in Color! Archived 10 August 2020 at the Wayback Machine, OIR Laboratory press release, 27 Feb 2020
- Looks like Earth has a new natural moon by Deborah Byrd, EarthSky, 26 Feb 2020
- MPEC 2020-D104 : 2020 CD3: Temporarily Captured Object, Minor Planet Center announcement, 25 Feb 2020
- 2020 CD3 at NeoDyS-2, Near Earth Objects—Dynamic Site
- 2020 CD3 at the JPL Small-Body Database