is a stony asteroid and near-Earth object, currently estimated to be the most potentially hazardous asteroid over the next 1000 years. It is in the Apollo group, approximately 1.1 kilometers in diameter. It was discovered on 9 August 1994, by astronomer Robert McNaught at the Siding Spring Observatory in Coonabarabran, Australia. With an observation arc of 47 years it has a very well known orbit and was observed by Goldstone radar in January 1997.
Of all the known asteroids larger than 1 km, has the largest probability of a "deep close encounter" with Earth over the next 1000 years. It has a close encounter with Earth in 2525, after which the uncertainty of its orbit increases.
Orbit and classification
orbits the Sun at a distance of 0.9–1.8 AU once every 1 years and 7 months (572 days). Its orbit has an eccentricity of 0.33 and an inclination of 33° with respect to the ecliptic.
On 17 January 1933, it passed from the Moon and then about an hour later made its closest known approach to Earth of . On 18 January 2022, it passed about from Earth.
+Close approaches Date JPL SBDBnominal geocentricdistance uncertaintyregion(3-sigma)1933-01-17 ± 65 km2022-01-18 ± 47 km2105-01-18 ± 1069 km
Physical characteristics
In the SMASS classification, is a common stony S-type asteroid.
Rotation period
In 1998, a rotational lightcurve of was obtained from photometric observations by Petr Pravec. Lightcurve analysis gave a well-defined rotation period of 2.5999 hours with a brightness amplitude of 0.29 magnitude ().
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, measures 1.052 kilometers in diameter and its surface has an albedo of 0.277. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and calculates a diameter of 1.30 kilometers based on an absolute magnitude of 16.8.
2022 flyby
At 18 January 2022 21:51 UTC, passed 5.15 lunar distances from Earth and had a 3-sigma uncertainty region of less than ± 50 km. It peaked at an apparent magnitude of about 10 placing it just outside the reach of common 7×50 binoculars. The nearly full moon being about 100 degrees from the asteroid during closest approach may have made it more difficult to observe with smaller telescopes. +2022 Moon/Earth approach Date & Time Approachto Nominal distance2022-01-18 18:58 Moon 2022-01-18 21:51 Earth
+ Sky trajectory with daily motion
Naming
As of 2022, this minor planet has not been named.
See also List of asteroid close approaches to Earth in 2022 – ~800 meters in diameter and passed 4.57 LD from Earth on 19 April 2017 – ~900 meters in diameter and will pass 0.65 LD from Earth on 26 June 2028
Notes
References
External links A Giant Asteroid Bigger Than The Empire State Building Is About to Zip Past Earth (Fiona MacDonald 5 January 2022) Huge asteroid will pass Earth safely 18 January (Eddie Irizarry 30 December 2021) Asteroid Lightcurve Database (LCDB), query form (info ) Sky and Telescope: The kilometer-wide, potentially hazardous asteroid 1994 PC1 will fly past Earth on 18 January. Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend