A Large Asteroid Will Zoom Past Earth on Christmas Eve

gizmodo.com
George Dvorsky

Fresh off the heels of Spooky the Halloween Asteroid comes news of yet another celestial object coming to pay us a visit during an important calendar event. But have no fear, this space rock won’t be the Grinch that annihilated Christmas…

Asteroid 2003 SD220, also known as asteroid 163899, is scheduled to make its closest approach to Earth on Christmas Eve, a.k.a. December 24, 2015. At more than 28 times the moon’s distance, NASA says it’s nothing to worry about.
Discovered back in 2003, the object is slated to skim past Earth at a very comfortable distance of 6,700,000 miles (around 11 million km), or 0.074 AU. At that distance, it will only be visible to professional and amateur astronomers, who should be able to capture optimal images of the giant space rock.

Perhaps the only remarkable thing about asteroid 2003 SD220, aside from its Christmas visit, is its size. Early estimates placed it between 0.7 to 1.5 miles (1.1 to 2.5 km) in length, but more recent observations place it around 1.25 miles (2 km ). Asteroid 2003 SD220 is currently moving at a speed of 17.5 miles/second, and appears to exhibit a very slow rotation of about one week.

The object, which kind of resembles a pickle or a chicken finger, will make its next return in 2018. NASA says the object won’t pose a threat to Earth for at least the next two centuries.
Contrary to some media reports, the asteroid will not trigger earthquakes when it makes its closest approach. As Eddie Irizarry writes at EarthSky:

Those assertions are misleading and incorrect. Even if 2003 SD220 were passing closer, it’s doubtful earthquakes would result. In fact, there’s no scientific evidence that an asteroid’s flyby can cause any seismic activity, unless it collides with Earth, but—in this case—that clearly will not be the case.

The object is on NASA’s NHATS list of potential human-accessible targets, so astronomers working at the Arecibo Observatory in Puerto Rico and Goldstone in California will be tracking the asteroid over the coming weeks.