Newly-discovered asteroid 2012 XE54 will fly by Earth tonight only 139,500 miles away or slightly more than half the distance to the moon. The rocky body, estimated at between 50-165 feet across (15-50 meters), was discovered only yesterday and will reach minimum distance tomorrow morning around 4:10 a.m. (CST) as it zips through northern Puppis southwest of Sirius. For a few hours before and after that, the asteroid should be visible in 8-inch and larger telescopes at around 13th magnitude. As with all these small bodies, 2012 XE54 will look like a starlight point of light on the move.
According to Pasquale Tricarico, research scientist at the Planetary Science Institute, there’s a good chance the asteroid will be partially eclipsed by Earth’s shadow between 7:22 – 8 p.m. (CST), an unusual if obscure event. Amateurs and professionals watching at that time might see a drop in the 2012 XE54’s brightness.
It’s not often we get to see an asteroid eclipse. The first known case happened in 2008 when 2008 TC3 passed into Earth’s shadow for an hour before entering the atmosphere, where it shattered and dropped about 10 lbs. of meteorites over Sudanese desert.
Just so we’re clear, we’ve nothing to fear from tonight’s flyby. The asteroid will pass safely by Earth like so many others have in recent years. The map above gives you a general idea of 2012 XE54’s path across the sky. To create your own detailed map to find it in a telescope, click over to the JPL HORIZONS site. There you can set your location and time interval and then plot the asteroid’s positions on a detailed star map. Or you can input its orbital elements into your star-charting program. To see a very cool animation of the possible eclipse, check out Pasquale Tricarico’s website.