2000 SG344


is a small Aten asteroid discovered in 2000. It is estimated to have a diameter of 37 meters and a mass of 7.1 kg.
Because of its very Earth-like orbit and because it would have been near the Earth in 1971, there was speculation that might not be an asteroid but a man-made object such as an S-IVB booster stage from a Saturn V rocket

Possible impacts with Earth

Until December 2004, it was considered to have the highest likelihood of any near-Earth object to impact Earth in the next 100 years. It is ranked a zero on the Torino scale of impact risk because of its small size and is listed on Sentry Risk Table. It was briefly surpassed in December 2004 by 99942 Apophis. The smaller asteroids and have a greater chance of impacting Earth.
Based on 31 observations of made from May 1999 to October 2000, there is about a 1 in 417 chance that it will collide with Earth between 2069 and 2113. Assuming the object is a rocky asteroid, the impact energy released would be an estimated 1.1 megatons of TNT, which would create an impact crater approximately wide assuming it does not explode in the atmosphere.

Planned NASA mission

In 2008, NASA considered this asteroid as a possible target for a manned mission using the Orion spacecraft, prior to a projected 2030 push to Mars. Those plans were since abandoned. will be observable in April 2028 at an apparent magnitude of 19.