When 2015 TB145 makes its closest approach on October 31, it will zoom past the Earth at a scant 0.0032 AU, or 1.3 lunar distances. That’s about 479,000 km or 297,000 miles. This will be the closest object to flyby Earth since 2006 when NEO 2004 XP14 flew past at 1.1 lunar distances. After the Halloween flyby, no object will come as close again until August 2027 when NEO 1999 AN10 will approach within 1.0 lunar distance.

NASA says that 2015 TB145 will safely pass by the Earth and continue to following along its exceptionally eccentric and high-inclination orbit—which may explain why it wasn’t discovered until only a few weeks ago.