1991 BA is a sub-kilometer asteroid, classified as near-Earth object of the Apollo group that was first observed by Spacewatch on 18 January 1991, and passed within 160,000 km (100,000 mi) of Earth.
The asteroid has a very short 5-hour observation arc that makes future predictions of its position unreliable.
[4] It is estimated that an impact would produce an upper atmosphere air burst equivalent to 16 kt TNT,[4] roughly equal to Nagasaki's Fat Man.
The asteroid would appear as a bright fireball and fragment in the air burst into smaller pieces that would hit the ground at terminal velocity producing a meteorite strewn field.
[7] Asteroid 2008 TC3 was an object of similar size that was discovered less than a day before its impact on Earth on October 7, 2008 and produced a fireball and meteorite strewn field in the Sudan.