© NASA/JPL-CaltechThis animation, created from 20 individual radar images, clearly show the rough outline of 2004 BL86 and its newly-discovered moon. Click for larger animation. Wonderful news! Asteroid 2004 BL86, which passed closest to Earth today at a distance of 750,000 miles (1.2 million km),
has a companion moon. Scientists working with NASA's 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, California, have released the first radar images of the asteroid which show the tiny object in orbit about the main body.
While these are the first images of it, the "signature" of the satellite was seen in light curve data reported earlier by Joseph Pollock (Appalachian State University, North Carolina) and Petr Prave (Ondrejov Observatory, Czech Republic) according to
Lance Bennerwho works with the radar team at Goldstone.
2004 BL86 measures about 1,100 feet (325 meters) across while its moon is approximately 230 feet (70 meters) across. The asteroid made its closest approach today (Jan. 26th) at 10:19 a.m. (CST), however it will peak in brightness this evening around 10 p.m. (4:00 UT) at magnitude +9.0. Unlike some flybys, 2004 BL86 will remain within a few tenths of a magnitude of peak brightness from 6 p.m. tonight (CST) through early tomorrow morning, so don't miss the chance to see it in your telescope.
Comment: Not necessarily. Some fireballs move uncharacteristically slowly. Apparently thousands of people observed this fireball ('genuine' UFOs are rarely observed by so many people simultaneously). See also: