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

2018 WV1's flyby trajectory
Discovery [1]
Discovered by	CSS H. Groeller[2][3]
Discovery site	Catalina Station
Discovery date	29 November 2018 (first observed only)
Designations
MPC designation	2018 WV1
Alternative designations	ZW0C3A5
Minor planet category	NEO · Apollo [1][4] Earth crosser
Orbital characteristics [4]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 2
Observation arc	13 days
Aphelion	1.1021 AU
Perihelion	0.9767 AU
Semi-major axis	1.0394 AU
Eccentricity	0.0603
Orbital period (sidereal)	1.06 yr (387 d)
Mean anomaly	169.02°
Mean motion	0° 55m 48.36s / day
Inclination	1.6525°
Longitude of ascending node	246.42°
Argument of perihelion	145.89°
Earth MOID	0.039 LD (12900 km)
Physical characteristics
Mean diameter	4 m (assumed)[5]
Absolute magnitude (H)	30.145[5] 30.183[4] 30.2[1]

Orbit

2018 WV₁ orbits the Sun at a distance of 0.98–1.10 AU once every 387 days (semi-major axis of 1.04 AU). Its orbit has an eccentricity of 0.06 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 is 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]

2018 flyby

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 remains inside the Earth's sphere of influence from 27 November till 7 December 2018.[8] During the flyby, its orbital period changes 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]

Other flybys

2018 WV₁ will pass within 0.38 AU (57,000,000 km) of Earth in December 2019.[4]

With a short observation arc of 1.69 days, the asteroid is on the Sentry risk list, with a probability of 1 in 11,000 for an impact between 2085 and 2118.[9]

Flyby gallery

• 
  Its closest approach will be between the earth and sun, so can't be observed.
• 
  Animation of 2018 WV1 orbit around Earth
     Moon ·    Earth ·    2018 WV1
• 
  Animation of 2018 WV1 orbit around Sun from 2017 to 2021
     Sun ·    Earth ·    2018 WV1

See also

• List of asteroid close approaches to Earth

References

External links

• List Of Apollo Minor Planets (by designation), Minor Planet Center
• 2018 WV1 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• 2018 WV1 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters