(163899) 2003 SD220 is a sub-kilometer asteroid and tumbling slow rotator, classified as near-Earth object and potentially hazardous asteroid of the Aten group, which orbit the Sun between Venus and Earth. Its orbital period of 0.75 years means that it orbits the Sun about 4 times for every 3 of the Earth. It was discovered on 29 September 2003, by astronomers of the Lowell Observatory Near-Earth-Object Search at Anderson Mesa Station near Flagstaff, Arizona.[2]
| 2003 SD220 from Arecibo Observatory on 16 December 2018 | |
| Discovery[1][2] | |
|---|---|
| Discovered by | LONEOS |
| Discovery site | Anderson Mesa Stn. |
| Discovery date | 29 September 2003 |
| Designations | |
| (163899) 2003 SD220 | |
| 2003 SD220 · 2000 AD229 | |
| NEO · PHA · Aten[1][2] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 15.96 yr (5,828 days) |
| Aphelion | 1.0019 AU |
| Perihelion | 0.6533 AU |
| 0.8276 AU | |
| Eccentricity | 0.2106 |
| 0.75 yr (275 days) | |
| 322.67° | |
| 1° 18m 33.12s / day | |
| Inclination | 8.4591° |
| 274.05° | |
| 326.47° | |
| Earth MOID | 0.0174 AU · 6.8 LD |
| Physical characteristics | |
| 0.80±0.02 km[3] 1.03 km (calculated)[4] | |
| 285±5 h[5][a] 11.9±0.2 days | |
| 0.20 (assumed)[4] 0.31±0.04[3] | |
| S (assumed)[4] | |
| 13.5 (2021 peak) | |
| 17.3[1][4] · 17.36[3] | |
![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:2003_SD220_orbit_2019.png)
![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:2003_SD220_earth_distances_2009-2027.png)
It passed about 28 lunar distances (LD) from the Earth on 25 December 2015. It came within about 7 LD (0.0189 AU) on 22 December 2018. Its peak brightness was about 13.13 magnitude on 16 December 2018.
Observations are planned for favorable flybys in 2021, 2024, and 2027. It passed with 14 LD (0.0363 AU) on 17 December 2021, and 34 LD (0.0884 AU) on 2 December 2024, and 54 LD (0.1382 AU) on 12 November 2027.[1]
Patrick Taylor of Arecibo Observatory suggested it could be a target for a future robotic mission.[6]
| Date | JPL SBDB nominal geocentric distance | uncertainty region (3-sigma) |
|---|---|---|
| 2021-12-17 | 5427633 km | ± 22 km |
It was observed in December 2015 at a distance of 28.3 lunar distances (0.07296 AU) on December 24, and its brightest was 15.22 magnitude on December 16. It showed an elongated shape, up to 2 km wide, described as being shaped like a sweet potato.
| GDSCC | Arecibo Observatory | |
|---|---|---|
![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:PIA20279.jpg) 17 December 2015 | ![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:PIA20280.jpg) 22 December 2015 | ![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:2003SD220.Arecibo.2015Dec03-16.75m.png) 3–16 December 2015 |
![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:2003_SD220_skypath_2015.png) |
2003 SD220 passed its closest distance of 7.34 LD (0.01899 AU) on 22 December 2018. It was on the list of Goldstone targets for December 2018 [7] to gain more information for the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS).[8]
![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:PIA22970-1041-Asteroid2003SD220-20181221.jpg) Asteroid 2003 SD220 radar images (15–17 December 2018)[9] |
Its peak brightness was about 13.1 magnitude on 16 December 2018, moving south from Ursa major and Boötes into Ophiuchus at closest approach and into Sagittarius.
![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:2003_SD220_skypath_2018.png) |
2003 SD220 passed at a distance of 14.1 lunar distances (0.03628 AU) on December 17, 2021. It was observed by the Goldstone Solar System Radar from November to December 2021.
![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:2003SD220_Goldstone_radar_Nov22.jpg) 22 November 2021 |
![[en] | (163899) 2003 SD220](https://en.wikipedia.org/wiki/File:2003_SD220_skypath_2021.png)
- ^ Lightcurve plot of (163899) 2003 SD220, by Brian Warner, Palmer Divide Station, California (2015). Rotation period of 285±5 hours with a brightness amplitude of 2.2±0.1 mag. Quality Code 2+. Summary figures at the LCDB
- ^ a b c d e f “JPL Small-Body Database Browser: 163899 (2003 SD220)” (2021-11-01 last obs.). Jet Propulsion Laboratory. Retrieved 22 November 2017.
- ^ a b c “163899 (2003 SD220)”. Minor Planet Center. Retrieved 22 November 2017.
- ^ a b c Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). “NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos”. The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ….152…63N. doi:10.3847/0004-6256/152/3/63. S2CID 119289027.
- ^ a b c d “LCDB Data for (163899)”. Asteroid Lightcurve Database (LCDB). Retrieved 22 November 2017.
- ^ Warner, Brian D. (April 2016). “Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 October-December”. The Minor Planet Bulletin. 43 (2): 143–154. Bibcode:2016MPBu…43..143W. ISSN 1052-8091. PMC 7243997. PMID 32455373.
- ^ Silent Night: Asteroid 2003 SD220 Sleighs by Earth on Christmas Eve Archived 2016-08-10 at the Wayback Machine Arecibo Observatory
- ^ “Goldstone Asteroid Schedule”.
- ^ “Accessible NEAs”.
- ^ Agle, DC; Brown, Dwayne; Wendel, JoAnna; Blue, Charles; Correa, Ricardo (21 December 2018). “Holiday Asteroid Imaged with NASA Radar”. NASA. Retrieved 21 December 2018.
![[en] | (163899) 2003 SD220](http://en.m.wikipedia.org/upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png){kind=logo}
- Radar Images of a Christmas-Eve Asteroid: An Early Gift for Astronomers Goldstone, JPL, December 23, 2015
- No, a “Massive” Asteroid Passing Earth on Thursday Will Not Cause Earthquakes By Phil Plait, December 21, 2015
- Mission Opportunities for Human Exploration of Nearby Planetary Bodies Cyrus Foster, Matthew Daniels (2016)
- (163899) 2003 SD220 at NeoDyS-2, Near Earth Objects—Dynamic Site
- (163899) 2003 SD220 at ESA–space situational awareness
- (163899) 2003 SD220 at the JPL Small-Body Database
