2018 BF3

2018 BF₃ is a micro-asteroid, classified as a near-Earth object of the Apollo group, approximately 20 meters (70 ft) in diameter. It was first observed on 20 January 2018, by astronomers of the Catalina Sky Survey at Mount Lemmon Observatory in Arizona, United States,^[1] the day after the closest flyby, due to its approach from the direction of the Sun.

2018 BF₃

Orbit and 1 Feb 2018 positions after flyby
Discovery[1]
Discovered by	CSS
Discovery site	Mount Lemmon Obs.
Discovery date	20 January 2018
Designations
MPC designation	2018 BF3
Minor planet category	NEO · Apollo[1][2]
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 7
Observation arc	3 days
Aphelion	2.2905 AU
Perihelion	0.8127 AU
Semi-major axis	1.5516 AU
Eccentricity	0.4762
Orbital period (sidereal)	1.93 yr (706 days)
Mean anomaly	54.414°
Mean motion	0° 30m 36s / day
Inclination	11.691°
Longitude of ascending node	298.99°
Argument of perihelion	117.22°
Earth MOID	3.87715×10−5 AU (0.15 LD)
Physical characteristics
Mean diameter	12–38 m[3] 18–40 m[4]
Absolute magnitude (H)	25.908[2]

Description

2018 BF₃ orbits the Sun at a distance of 0.8–2.3 AU once every 23 months (706 days; semi-major axis of 1.55 AU). Its orbit has an eccentricity of 0.48 and an inclination of 12° with respect to the ecliptic.^[2] With an aphelion of 2.3 AU, it is a Mars-crosser, crossing the orbit of the Red Planet at 1.666 AU. It is also an Earth-crosser, as are all Apollo asteroids. The body's observation arc begins at Mount Lemmon with its first observation on 20 February 2018.^[1]

2018 flyby

On 19 January 2018, the object passed at a nominal distance of only 0.00162 AU; 150,000 mi (242,000 km) from Earth.^[2] This corresponds to 0.63 LD.^[3] Close approaches are projected for 28 October 2019 and 26 August 2021, both at a much larger distance (0.24 AU).^[2]

2018 flyby: Its path across the sky on 19 January was east to west (2 hour positions shown) (left). Seen from space, it passes just outside geosynchronous orbit (right).

Physical characteristics

The Minor Planet Center estimates a diameter of 12–38 meters (39–120 ft),^[3] concurring with other estimates of 18–40 meters (59–130 ft).^[4] As of 2018, no rotational lightcurve of this object has been obtained from photometric observations. The asteroids's rotation period, pole and shape remain unknown.^[2]

Numbering and naming

This minor planet has not yet been numbered.^[1]

See also

• List of asteroid close approaches to Earth in 2018