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 6 December 2018 ( JD 2458458.5)
Uncertainty parameter 2
Observation arc	14 days
Aphelion	1.1149 AU
Perihelion	0.9715 AU
Semi-major axis	1.0432 AU
Eccentricity	0.0686
Orbital period (sidereal)	1.065 yr (389 d)
Mean anomaly	38.51 °
Mean motion	0° 55m 30s / day
Inclination	1.9054°
Longitude of ascending node	248.51°
Argument of perihelion	141.37°
Earth  MOID	0.1444 LD (55500  km)
Physical characteristics
Mean diameter	4  m (assumed) [5]
Absolute magnitude (H)	30.145 [5] 30.183 [4] 30.2 [1]

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]}

Orbit

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]

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 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]

Other flybys

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]

Flyby gallery

• 
  Its closest approach was 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
  • Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
• 2018 WV1 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters