(875163) 1998 SH2

(875163) 1998 SH2
Discovery
Discovered bySpacewatch
Discovery siteKitt Peak Observatory
Discovery date17 September 1998
Designations
1998 SH2 · 2016 EC156
NEO · Apollo · PHA
Orbital characteristics
Epoch 9 June 2026 (JD 2461200.5)
Uncertainty parameter 0
Observation arc27.10 years
Aphelion4.701 AU
Perihelion0.785 AU
2.743 AU
Eccentricity0.71379
4.543 years
70.005°
0° 13m 1.115s / day
Inclination2.426°
6.074°
268.72°
Earth MOID0.019 AU
Jupiter MOID0.499 AU
Physical characteristics
0.383 ± 0.057 km (0.238 ± 0.035 mi)
0.058±0.024
20.88

(875163) 1998 SH2 is an Apollo-type near-Earth asteroid with an estimated diameter of about 383 m (1,257 ft). It was discovered by the Spacewatch survey of the Kitt Peak National Observatory from Arizona, USA on 17 September 1998.

Physical characteristics

Infrared observations from the NEOWISE spacecraft revealed that asteroid 1998 SH2 may have a diameter of about 383 m (1,257 ft) assuming a geometric albedo of about 0.058. Astrometric measurements up to 2025 revealed orbital perturbations consistent with weak outgassing, indicating that this object might be also a comet.

Orbit

As of June 2026, 1998 SH2 currently has a perihelion of about 0.785 AU (117.4 million km) and aphelion of about 4.701 AU (703.3 million km) from the Sun, completing one revolution once every 4.54 years.

It made a close encounter with Earth at a distance of 0.0208 AU (3.11 million km) on 30 August 2025. By 2037, it will approach Jupiter at a distance of 0.98 AU (147 million km), followed by another Earth flyby at 0.0695 AU (10.40 million km) away on 8 September 2052. It is considered a potentially hazardous asteroid, however there is no significant impact risk with Earth in the foreseeable future.

See also

References

  1. 1 2 A. Sugie; G. J. Garradd; F. B. Zoltowski; et al. (19 September 1998). G. V. Williams (ed.). "1998 SH2". Minor Planet Electronic Circular. 1998-S10. Bibcode:1998MPEC....S...10S.
  2. ↑ A. F. Tubbiolo; R. Matson (15 March 2016). G. V. Williams (ed.). "1998 SH2 = 2016 EC156". Minor Planet Electronic Circular. 2016-E174. Bibcode:2016MPEC....E..174T.
  3. 1 2 "(875163) 1998 SH2 – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 18 July 2026.
  4. 1 2 "(875163) = 1998 SH2 = 2016 EC156". Minor Planet Center. Retrieved 19 July 2026.
  5. 1 2 3 J. R. Masiero; C. Nugent; A. K. Mainzer; et al. (2017). "NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos". The Astronomical Journal. 154 (4): 168–178. arXiv:1708.09504. Bibcode:2017AJ....154..168M. doi:10.3847/1538-3881/aa89ec.
  6. ↑ D. Farnocchia; O. R. Hainaut; D. Z. Seligment (2026). "Non-gravitational acceleration indicative of cometary activity of near-Earth object" (PDF). Nature Astronomy. 10 (9): 1283–1291. Bibcode:2026NatAs..10.1283F. doi:10.1038/s41550-026-02913-7. PMC 13581609. PMID 42755534.
  7. ↑ I. J. O'Neill; K. Fox; M. Wasser (16 July 2026). "NASA Study Finds Near-Earth Asteroid Is Actually Comet". jpl.nasa.gov. NASA / Jet Propulsion Laboratory. Retrieved 18 July 2026.
  8. 1 2 R. Weryk; R. Wainscoat; L. Wells; et al. (15 July 2026). D. W. Green (ed.). "(875163) = Comet P/1998 SH2 = P/2016 EC156" (TXT). Central Bureau Electronic Telegrams (5716): 1.
  9. ↑ K. Kasal (15 July 2026). "Asteroid with unexplained orbital shift turns out to be a 'dark comet'". Phys.org. Retrieved 19 July 2026.