2020 HS7

2020 HS7
Discovery[1][2]
Discovered byPan-STARRS 2
Discovery siteHaleakala Obs.
Discovery date27 April 2020
Designations
2020 HS7
NEO · Apollo[3][1]
Orbital characteristics[3]
Epoch 9 August 2022 (JD 2459800.5)
Uncertainty parameter 6
Observation arc1 day
Aphelion2.904 AU
Perihelion0.793 AU
1.849
Eccentricity0.5709
2.51 yr (918 days)
308.988°
0° 23m 31.807s / day
Inclination4.732°
38.531°
245.692°
Physical characteristics
Dimensionsa/b ≥ 1.04[4]
4–8 m[5]
2.9945±0.0002 s[4]
2.9938±0.0002 s[4]
29.10±0.36[3]

2020 HS7 is a very small asteroid classified as a near-Earth object of the Earth-crossing Apollo group. When it was discovered by the Pan-STARRS 2 survey on 27 April 2020, the asteroid was initially calculated to have a 10% chance of impact with Earth before being ruled out by improved orbit determinations from additional observations.[6] Although there is now no risk of impact with Earth, it did make a close approach 42,700 kilometres (26,500 mi) from Earth on 28 April 2020, with a flyby speed of 15.6 kilometres per second (9.7 mi/s) relative to Earth.[3][7][5] The asteroid will not make any close encounters within 1 lunar distance (380,000 km; 240,000 mi) of Earth in the next 100 years.[3]

Observations by Kiso Observatory in Nagano, Japan show that the asteroid rotates extremely rapidly with a rotation period of 3 seconds, making it the fastest-rotating asteroid known as of 2022.[4] No other near-Earth asteroid of similar size is known to have a rotation period shorter than 10 seconds, which could be attributed to the tangential component of the YORP effect accelerating their rotation far beyond this period.[4] The asteroid exhibits a very small light curve amplitude of 0.07 magnitudes, which either implies a nearly spherical shape or a pole-on rotation during observations.[4]

  1. ^ a b Cite error: The named reference MPC-object was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference MPEC-2020-H212 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference jpldata was invoked but never defined (see the help page).
  4. ^ a b c d e f Cite error: The named reference Beniyama2022 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference space_050520 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference ssa_072920 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference space_042820 was invoked but never defined (see the help page).