A huge asteroid is approaching Earth and coming closest to it on Christmas Eve. But contrary to alarmist reports, it isn't a cause for concern, and will in fact be a great opportunity for radar observations in the coming days.
Also known as 2003 SD220, Asteroid 163899 will pass at a safe distance and will be some 6.7 million miles or 11 million kilometers from the Earth's surface - the space rock's passage far enough to be imaged only by professional and amateur astronomers.
Done at over 28 times the Earth-moon distance, the asteroid fly-by, experts asserted, will also not lead to any earthquake or seismic activity except when there is a collision, which is hardly the case as far as NASA is concerned.
"The 2015 apparition is the first of five encounters by this object in the next 12 years when it will be close enough for a radar detection," noted the space agency's asteroid radar research group, which added that measurements may allow them to estimate the asteroid's mass and in turn understand its bulk density and internal structure.
2003 SD220, which will appear again in December 2018 and 2021, was discovered by the Lowell Observatory Near-Earth Object Search (LONEOS) program in Arizona in Sept. 29, 2003 as indicated by its name.
Based on preliminary estimates, the asteroid has a size of 0.7 to 1.5 miles (1.1 to 1.5 kilometers), with estimates later bumped up post-radar observations from Puerto Rico's Arecibo telescope. The most recent project size: about 1.25 miles (2 kilometers) in length.
However, the so-called Christmas asteroid - believed to have quite a slow rotation of around a week - will be more difficult to view due to its sheer distance. In contrast, other asteroids such as 2004 BL86 and 2015 TB145 were visible via 8-inch telescopes.
Astronomers are already having a field day observing Asteroid 163899 through bouncing radio signals emanating from its surface. The Puerto Rican observatory is focusing on it from Dec. 3 to 17, while California's Goldstone Antenna is tasked to analyze it from Dec. 5 to 20.
"2003 SD220 is on NASA's NHATS list of potential human-accessible targets, so observations of this object are particularly important," stated NASA astronomer Lance Benner in a document from Goldstone radar observations.
The Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) aims to identify such near-Earth apparitions that may be suitable for human-space-flight rendezvous missions in the future.
The Obama administration recently signed into law the space mining legislation allowing U.S. space firms to own and sell resources mined from asteroids and similar space bodies.
Some experts, however, echoed the danger of the law violating an international space treaty barring "harmful contamination" and "national appropriation" of such celestial bodies.