2017 XX61 is a small near-Earth object, approximately 17 meters (56 feet) in diameter, that transited Earth at 8 lunar distances on 18 December 2017 at 14:54 UTC. The Apollo asteroid on an eccentric orbit was first observed by the Mount Lemmon Survey and was lost on the following night. As of 2020, it has not been recovered.[2]

2017 XX61
Discovery[1]
Discovered byMLS
Discovery siteMount Lemmon Obs.
Discovery date15 December 2017
Designations
2017 XX61
NEO · Apollo[1][2]
Orbital characteristics[2]
Epoch 16 December 2017 (JD 2458103.5)
Uncertainty parameter 8[2] · 7[1]
Observation arc(1 day)
Aphelion3.2799 AU
Perihelion0.7945 AU
2.0372 AU
Eccentricity0.6100
2.91 yr (1,062 days)
345.28°
0° 20m 20.4s / day
Inclination8.4261°
81.755°
67.340°
Earth MOID0.0162 AU (6.3 LD)
Physical characteristics
Mean diameter
17 m (est. at 0.14)[3]
26.6[1][2]

Description edit

2017 XX61 was first observed on 15 December 2017, by astronomers of the Mount Lemmon Survey at Mount Lemmon Observatory near Tucson, Arizona.[1]

It orbits the Sun at a distance of 0.8–3.3 AU once every 2 years and 11 months (1,062 days; semi-major axis of 2.04 AU). Its orbit has an eccentricity of 0.61 and an inclination of 8° with respect to the ecliptic.[2]

2017 XX61 has an Earth minimum orbital intersection distance of 0.0162 AU (2,420,000 km), which translates into 6.3 lunar distances.[2] The asteroid also approached Mars on 11 May 2018.[2]

A generic magnitude-to-diameter conversion gives a mean-diameter of 13–27 meters, for an absolute magnitude of 26.6,[2] and an assumed albedo between 0.25 and 0.057, which typically correspond to the composition of a stony and carbonaceous body, respectively.[3]

References edit

  1. ^ a b c d e "2017 XX61". Minor Planet Center. Retrieved 17 January 2018.
  2. ^ a b c d e f g h i "JPL Small-Body Database Browser: (2017 XX61)" (2017-12-16 last obs.). Jet Propulsion Laboratory. Retrieved 17 January 2018.
  3. ^ a b "Asteroid Size Estimator". CNEOS NASA/JPL. Retrieved 17 January 2018.

External links edit