Two newly discovered asteroids - 2018 RY5 and 2018 RZ5 - flew past Earth within 1 lunar distance on September 12, 2018, one day before they were first observed. RZ5 is one of the closest known asteroids to flyby us this year and RY5 one of the biggest (nominal distance <= 1LD).
Asteroid 2018 RY5 flew past us at 17:12 UTC at a distance of 0.47 LD / 0.00120 AU (179 517 km / 111 546 miles) and a speed (relative to the Earth) of 23.73 km/s.
It belongs to the Apollo group of asteroids and has an estimated diameter between 14 and 31 m (46 - 102 feet). It was first observed at Catalina Sky Survey on September 13.
Asteroid RZ5 also belongs to the Apollo group of asteroids. It flew past us at 20:08 UTC at a distance of 0.13 LD / 0.00033 AU (49 367 km / 30 675 miles) and a speed (relative to the Earth) of 20.23 km/s.
It was also discovered by astronomers at Catalina Sky Survey on September 13. Its estimated diameter is between 3.1 and 6.8 m (10 - 22 feet).
This is the 48th known asteroid to flyby Earth within 1 lunar distance since the start of the year and 8th so far this month.
Image credit: The Watchers
As of September 12, there are 18 757 known near-Earth objects (NEOs). 18 650 of them are near-Earth asteroids. Of those, 894 have diameters roughly one km (0.62 mi) or more. Since the start of the year, we have discovered 1 197 new NEOs. All of them were asteroids.
Featured image credit: CNEOS