“Potentially Hazardous” Asteroid To Zip Past Earth Just After Christmas

It’s a Christmas miracle – albeit potentially hazardous and slightly late.

A huge asteroid is set to safely pass by Earth in the early hours of December 26, just as Santa starts clocking in for his holidays. The space rock – labeled 310442 (2000 CH59) – is expected to make its closest approach to Earth at around 07:54 UTC, according to NASA’s Center for Near Earth Object Studies (CNEOS).

310442 (2000 CH59) is estimated to be up to 620 meters (2,034 feet) in diameter – taller than the One World Trade Center in New York City. Despite some newspapers claiming it’s a “killer Christmas space rock”, don’t expect the asteroid to ruin your holidays. Zooming passed at over 12 kilometers (7.4 miles) per second, the asteroid is expected to be 7,180,697 kilometers (0.048 astronomical units) away from Earth at its closest approach, around 19 times the distance between the Earth and the Moon.

This might sound like a hell of a long-distance in human terms, but it’s close enough to be called a “potentially hazardous” near-Earth object under the definitions of CNEOS.

As this image illustrates, Earth and 310442 (2000 CH59) will nearly cross paths on December 26, 2019. NASA JPL/CNEOS

This might sound like a hell of a long-distance in human terms, but it’s close enough to be called a “potentially hazardous” near-Earth object under the definitions of CNEOS.

“At closest, CH59 will be about 19 times farther than the moon. Over many centuries and millennia [these asteroids] might evolve into Earth-crossing orbits,” Paul Chodas, director of the CNEOS, told Newsweek. “So it is prudent to keep tracking [them] for decades to come and to study how their orbits might be evolving.”

With a brightness of around 19.9 absolute magnitudes, the asteroid won’t be visible to the naked eye. The brightness (and, therefore, the visibility) of an asteroid in our sky depends on its size, distance, and reflectivity. This reflectivity can be determined by a number of factors, including its shape and chemical composition. Although it’s relatively close and large for a near-Earth object, it won’t be visible with most commercially available optical telescopes either.

Like a pair of astronomical fireworks deep in the night sky, the end of the decade will also be celebrated with two other asteroids around New Year’s eve – one on December 31 at 05:04 UTC and another on January 1 at around 16:08.

Tom Hale
IFL Science