2015 TB145 is a near-Earth asteroid roughly 280–620 meters (900–2,000 feet) in diameter that will pass about 1.27 lunar distance from Earth on 31 October 2015 at about 17:00 UT.
During closest approach to Earth the asteroid will reach about apparent magnitude 10, but the Moon will be a 80% waning gibbous. At peak brightness, the asteroid will be a challenging target for amateur astronomers with small telescopes, but it will be best seen in the Northern hemisphere.
On 31 October 2015 at 11:00 UT (4AM PDT) the asteroid will be in the constellation of Taurus about 9 degrees from the Moon and moving at a rate of 3.4 degrees per hour. At the time of closest approach of 17:00 UT the asteroid will be in the constellation of Ursa Major about 56 degrees from the Moon and moving at a rate of 14.7 degrees per hour.
After closest approach the asteroid will quickly become too faint and be too close to the Sun in the sky to be seen.