is a small Aten asteroid that made a close approach of 0.54 lunar distances from Earth on January 9, 2017. It was the largest asteroid to pass less than 1 lunar distance from Earth since on August 28, 2016. The Catalina Sky Survey observed it first on January 7, 2017, only two days before its closest approach. At its brightest, reached apparent magnitude 12.2. Shortly after, it moved too close to the Sun to be seen by telescopes.
The asteroid frequently makes close approaches to Earth, possibly passing as close as to Earth on January 9, 2069, however it will most likely pass much farther away.
Based on an absolute magnitude of 26.1, is likely across, assuming a typical asteroid albedo of between 0.05 and 0.3.
References
External links Minor Planet Center flyby diagram Newfound Asteroid Gives Earth a Close Shave (space.com) Asteroid 2017 AG13 passed between the Earth and Moon and we hardly noticed, redorbit.com, April 17, 2018