2021 SG
Near-Earth asteroid
2021 SG is a near-Earth asteroid, with an estimated diameter of 42 to 94 meters, that passed about half a lunar distance from Earth on 16 September 2021. It approached from the direction of the Sun, so it was invisible until a day later.[6] It completes its highly eccentric orbit in 2.24 years. 2021 SG is an Apollo asteroid with a 1.71 AU semimajor axis, and a 0.473 AU perihelion (near Mercury at perihelion) out to a 2.95 AU aphelion (between Mars and Jupiter). With an absolute magnitude (H) of 24.0, it is possibly the largest asteroid to pass within 1 lunar distance of Earth during 2021.[2]
References
- ^ a b "2021 SG". Minor Planet Center. International Astronomical Union. Retrieved 11 December 2021.
- ^ a b c "MPEC 2021-S24 : 2021 SG". Minor Planet Electronic Circular. Minor Planet Center. 17 September 2021. Retrieved 11 December 2021.
- ^ "2021 SG". NEO Exchange. Las Cumbres Observatory. 17 September 2021. Retrieved 11 December 2021.
- ^ a b c "JPL Small-Body Database Browser: (2021 SG)" (2021-09-24 last obs.). Jet Propulsion Laboratory. Retrieved 11 December 2021.
- ^ "NEO Earth Close Approaches". Center for Near Earth Asteroid Studies. Jet Propulsion Laboratory. Retrieved 11 December 2021.
- ^ "EarthSky | Asteroid 2021 SG came from the sun's direction". 20 September 2021.
External links
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Wikimedia Commons has media related to 2021 SG.
- 2021 SG at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters
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2021 in space
- « 20202022 »
telescope launches
![Space probes launched in 2021](http://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/15px-Symbol_category_class.svg.png)
- Tiangong space station Tianhe (April 2021)
- Lucy (Oct 2021)
- DART / LICIACube (Nov 2021)
- James Webb Space Telescope (Dec 2021)
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- Winchcombe meteorite
- Asteroid close approaches
- 2021 AV7
- 2020 XR
- 2016 DV1
- 2021 DW1
- 99942 Apophis
- (231937) 2001 FO32
- 2021 GW4
- 2021 PH27
- 2016 AJ193
- 2021 SG
- 2021 TP21
- 2021 UA1
- 2019 XS
- 3361 Orpheus
- 1994 WR12
- 4660 Nereus
- (163899) 2003 SD220
- 2018 AH
![Exoplanets discovered in 2021](http://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/15px-Symbol_category_class.svg.png)
- Alpha Centauri Ab (unconfirmed)
- COCONUTS-2b
- Gliese 486
- HD 108236 f
- HD 110082 b
- Kepler-1704b
- KOI-5Ab
- L 98-59
- e
- f?
- Lalande 21185 c
- Lambda Serpentis b
- LHS 1678
- b
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- NGTS-13b
- NGTS-14Ab
- OGLE-2019-BLG-0960Lb
- PDS 70c circumplanetary disk
- TIC 172900988 b
- TOI-178
- b
- c
- d
- e
- f
- g
- TOI-755
- b
- c
- Vega b (unconfirmed)
- YSES 2 b
- QSO J0313−1806 (distant quasar)
- ID2299 (elliptical galaxy)
- TIC 168789840 sextuple system
- V723 Mon black hole candidate
- 2018 AG37 (TNO)
- 2021 DR15 (TNO)
- ALESS 073.1 (spiral galaxy)
- PJ352–15 astrophysical jet
- 2MASS J0348−6022 (rapidly-rotating brown dwarf)
- ZTF J1901+1458 (massive white dwarf)
- WISE 1534–1043 (brown dwarf)
- Andy's object (radio source)
![Comets in 2021](http://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/15px-Symbol_category_class.svg.png)
- C/2021 A1 (Leonard)
- C/2021 J1 (Maury-Attard)
- (248370) 2005 QN173
- 8P/Tuttle
- C/2014 OG392 (PanSTARRS)
- C/2014 UN271 (Bernardinelli-Bernstein)
- C/2021 T4 (Lemmon)
- P/2021 U3 (Attard-Maury)
exploration
Outer space portal
Category:2020 in outer space — Category:2021 in outer space — Category:2022 in outer space
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