Asteroid 2017 SS12 flew past Earth at 0.67 LD, one day before discovery

A newly discovered asteroid designated 2017 SS12 flew past Earth at 0.67 LD (~ 257 280 km / 159 866 miles) at 15:33 UTC on September 24, 2017, one day before it was discovered. This is the 33^rd known asteroid to flyby Earth within 1 lunar distance since the start of the year.

2017 SS12 belongs to the Apollo group of asteroids. Its estimated size is between 7 and 24 m (22 and 78 feet).

It was first observed at Catalina Sky Survey on September 25, one day after its closest approach.

[ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Close-Approach Data ]

The last time any known asteroid flew past Earth within 1 lunar distance was on September 20. On that day, three of them flew past us (2017 SM2, 2017 SR2, and 2017 SZ32) within 13 hours.

Reference:

Asteroid 2017 SS12 at Minor Planet Center; at CNEOS

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 one-hour intervals. The Moon's orbit is gray. The blue arrow points in the direction of Earth's motion and the yellow arrow points toward the Sun. Credit: Minor Planet Center