A newly discovered asteroid designated 2018 XA4 flew past Earth at a distance of 0.97 LD / 0.00248 AU (371 002 km / 230 530 miles) on December 11, 2018. This is 73rd known asteroid to flyby Earth within 1 lunar distance since the start of the year.
This object belongs to the Apollo group of asteroids. It was first observed at Mt. Lemmon Survey, Arizona on December 13, 2 days after its close approach to our planet.
2018 XA3 has an estimated diameter between 4.1 and 9.2 m (13 and 30 feet) and it flew past us at a speed (relative to the Earth) of 12.77 km/s at 15:42 UTC.
This is the second known <1LD flyby since December 2 and 73rd since the start of the year and the second this month.
Featured image: The green line indicates the object's apparent motion relative to the Earth, and the bright green marks are the object's location at approximately half hour intervals. The Moon's orbit is grey. The blue arrow points in the direction of Earth's motion and the yellow arrow points toward the Sun. Credit: Minor Planet Center