2018 WV1 is a very small asteroid and near-Earth object of the Apollo group that passed within 27,000 kilometers (17,000 miles) of the Earth's surface on 2 December 2018.[6][7] It was first observed on 29 November 2018 by Hannes Gröller with the Catalina Sky Survey at Catalina Station on Mount Bigelow, Arizona, in the United States.[1][3]
2018 WV1 orbits the Sun at a distance of 0.97–1.11 AU once every 389 days (semi-major axis of 1.04 AU). Its orbit has an eccentricity of 0.07 and an inclination of 2° with respect to the ecliptic.[4]
As an Apollo asteroid with an orbital period slightly larger than that of the Earth, its orbit is very similar to that of the Earth, indicating that the object could potentially be a piece of lunar ejecta, a fragment of the Moon that was ejected into space when a larger asteroid hit the Moon a long time ago.[7]
On 2 December 2018, the asteroid passed about 33,000 km (21,000 mi) from Earth, traveling 5.2 kilometres per second (3.2 mi/s) relative to Earth and briefly reaching apparent magnitude 17.[4] This was the third-closest approach by an asteroid in 2018, and the 70th asteroid of the year that passed within 1 lunar distance of Earth.[6] Its absolute magnitude of 30.1 indicates a diameter between 2.5 and 5.6 metres.[7]
2018 WV1 remained inside the Earth's sphere of influence from 27 November till 7 December 2018.[8] During the flyby, its orbital period changed from 1.13 to 1.06 years.
At the time of its discovery, 2018 WV1 had a 2% chance to hit Earth in early December 2018. The possibility of impact was ruled out soon after, as more data became available.[7]
2018 WV1 passed within 0.38 AU (57,000,000 km) of Earth in December 2019.[4]
The asteroid, when first discovered, was placed on the Sentry risk table. Further observations refined its orbit enough to remove it from the table on December 3, 2018[9]