On Sunday (Sept. 7), a house-sized interplanetary interloper will fly past Earth at a distance of only 25,000 miles — that’s one-tenth of the distance from the Earth to the moon — possibly giving some Southern Hemisphere sky-watchers a glimpse pre-dawn on Monday.
The 20 meter (60 foot) wide asteroid 2014 RC was discovered on Aug. 31 by the Catalina Sky Survey near Tucson, Ariz., and then independently detected the following night by the Pan-STARRS 1 telescope, on Maui, Hawaii. Follow-up observations quickly deduced that this particular space rock was destined to make a very close approach to our planet, dipping close to the orbital distance of geosynchronous communications and weather satellites.
Although this particular space rock is relatively small, it’s approximately the same size as the meteor that exploded over Chelyabinsk, Russia, on Feb. 15, 2013. That small asteroid exploded with 30 times more energy than the atomic bomb that was dropped on Hiroshima when it hit the atmosphere, creating a powerful shockwave that caused thousands of injuries and millions of dollars worth of property damage.
Fortunately, there is no risk of 2014 RC hitting Earth and even if it did, it would more likely impact the skies over an unpopulated part of the globe. But depending on its composition — which is unknown at this time — it could deliver an energetic impact.
Even though it won’t hit (and astronomers don't believe it will be a threat in the foreseeable future) the asteroid will make its point of closest approach during the early Monday morning over New Zealand at 6:18 a.m. local time (2:18 p.m. EDT, Sunday), so amateur astronomers with small telescopes may be able to pick out the speeding 11.5 magnitude dot in the twilight skies.
This event once again reminds us that the solar system is crowded with millions of small asteroids and their early detection not only shows that our astronomical techniques are improving, by closely observing asteroid flybys we can better understand what these space rocks are made of and decipher whether or not they may pose a threat during future orbits.