Near-Earth asteroid spotted by amateurs

For the first time, amateur astronomers have helped discover a near-Earth asteroid that could – in the far future – conceivably come close enough to Earth to pose a threat. The asteroid has been designated 2011 SF108. The amateur sky sleuths were participating in the Space Situational Awareness (SSA) program of the European Space Agency (ESA).

Amateur astronomer Rainer Kracht and colleagues found the space rock in September 2011. The four-night survey used the 1-meter telescope at ESA’s Optical Ground Station (OGS) on Mount Teide, a volcanic mountain on the island of Tenerife in the Canary Islands.

Astronomers recognize asteroids against the backdrop of fixed stars because they move relative to the stars. In this animation, 2011 SF108 is the white blob moving left-to-right in the upper center of the image. The white blob moving left-to-right at the lower center is a known asteroid and the single pixel jumping at upper-center-left is a digital artifact.

The orbit of asteroid 2011 SF108 brings it no closer than about 30 million kilometers (about 20 million miles, or about 80 times the moon’s average distance from Earth). In other words, it stays a safe distance away, and no impact or near-impact is looming from this asteroid.

Still, it’s a noteworthy discovery. Although 2011 SF18 isn’t the first asteroid found under SSA sponsorship, it’s the first that qualifies as a near Earth object. Astronomers want to know about and track near-Earth asteroids for reasons that have become obvious in recent decades: the possible hazard they might pose to our human society in the future.

The successful discovery of 2011 SF108 might signal the first of many more asteroid sightings around the world as by amateur astronomers, as they become equipped with advanced technology. In other words, with so many people able to look, we’re now safer than ever from an asteroid collision with Earth. Woot!

Bottom line: Amateur astronomers have made their first discovery of a near-Earth asteroid. Rainer Kracht and colleagues found the asteroid – which has been designated 2011 SF108 – in September 2011. The four-night survey used the 1-meter telescope at ESA’s Optical Ground Station (OGS) on Mount Teide, a volcanic mountain on the island of Tenerife in the Canary Islands.