Astronomy:2018 WV1

2018 WV₁

2018 WV1's flyby trajectory
Discovery
Discovered by	CSS H. Groeller
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  Earth crosser
Orbital characteristics
Epoch 6 December 2018 (JD 2458458.5)
Uncertainty parameter 2
Observation arc	14 days
|{{{apsis}}}|helion}}	1.1149 AU
|{{{apsis}}}|helion}}	0.9715 AU
Semi-major axis	1.0432 AU
Eccentricity	0.0686
Orbital period	1.065 yr (389 d)
Mean anomaly	38.51°
Mean motion	0° 55m 30s / day
Inclination	1.9054°
Longitude of ascending node	248.51°
|{{{apsis}}}|helion}}	141.37°
Earth MOID	0.1444 LD (55500 km)
Physical characteristics
Mean diameter	4 m (assumed)
Absolute magnitude (H)	30.145 30.183 30.2

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. 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.

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.

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.

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. 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. Its absolute magnitude of 30.1 indicates a diameter between 2.5 and 5.6 metres.

2018 WV₁ remained inside the Earth's sphere of influence from 27 November till 7 December 2018. 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.

Other flybys

2018 WV₁ passed within 0.38 AU (57,000,000 km) of Earth in December 2019.

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

Flyby gallery

• 

  Its closest approach was between the Earth and Sun, so can't be observed.

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  Animation of 2018 WV1 orbit around Earth
     Moon ·    Earth ·    2018 WV1

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  Animation of 2018 WV1 orbit around Sun from 2017 to 2021
     Sun ·    Earth ·    2018 WV1

See also

• List of asteroid close approaches to Earth

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