NASA: Today an asteroid, which is roughly 569 metres in diameter, will fly by the Earth. The asteroid, 2006 QQ23 is as big as the Empire State Building and is considered a NEO (Near-Earth Object). The 2006 QQ23 will fly within 0.049 astronomical units (1 AU = Distance between Earth and the Sun) at about 16,740 kmph.
The object being within 0.5 AU of Earth and greater than 140 meters in diameter has been labelled as a potentially hazardous object. The asteroid though, is not considered as a threat and has been called more or less benign by Lindley Johnson and Kelly Fast of NASA’s Planetary Defence Coordination Office, responsible for tracking near-Earth objects in our Solar System.
Asteroids and meteors are said to fly by the Earth and Moon all the time and are not considered a threat. The few fragments that do enter the Earth explode on atmospheric entry and lead to bright meteor showers. Meteorites are remnants of these fragments are found on Earth’s Surface. Most of these objects do not pose a threat but are constantly monitored to ensure they don’t turn into a threat.
According to the Jet Propulsion Laboratory, there are about 900 NEO with a diameter greater than one kilometre making them larger than 2006 QQ23. NASA says there is no significant risk from these NEO’s for the next 100 years. The highest risk that an asteroid will hit Earth is a chance of impact by 2009 FD in 2185 which is 1 in 714, about 2 percent.
NASA and other space agencies are working on methods to deflect asteroids that have a higher chance of impact through techniques like Gravity Tractor. Unlike the tractor beams from sci-fi movies, Gravity Tractor utilizes a spacecraft that will use its relative gravity with the asteroid to deflect it into a different trajectory without landing on it. There other methods like kinetic impactor or using nuclear explosion.
