from the duck-just-in-case dept.
Mark your calendar for Oct. 12. That's when asteroid 2012 TC4 will slip past Earth at an expected distance of around 27,300 miles (44,000 kilometers). The European Southern Observatory's Very Large Telescope in Chile recently caught sight of the asteroid, which could be up to 100 feet (30 meters) in size.
NASA is leading a coordinated international campaign to observe TC4. In July, NASA suggested the asteroid could squeeze in as close as 4,200 miles (6,800 kilometers), but the European Space Agency's latest estimates give us more breathing room.
Geostationary equatorial orbit (GEO) is at about 35,786 km above mean sea level.
Also at Phys.org (AFP).
2012 TC4 is estimated to be 45 to 100 feet (15 to 30 meters) in size. Orbit prediction experts say the asteroid poses no risk of impact with Earth. Nonetheless, its close approach to Earth is an opportunity to test the ability of a growing global observing network to communicate and coordinate their optical and radar observations in a real scenario.
This asteroid was discovered by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) on Hawaii back in 2012. Pan-STARRS conducts a near-Earth object (NEO) survey funded by NASA's NEO Observations Program, a key element of NASA's Planetary Defense Coordination Office. However, 2012 TC4 traveled out of the range of asteroid-tracking telescopes shortly after it was discovered.
Based on the observations they were able to make in 2012, asteroid trackers predicted that it should come back into view in the fall of 2017. Observers with the European Space Agency and the European Southern Observatory were the first to recapture 2012 TC4, in late July 2017, using one of their large 8-meter aperture telescopes. Since then, observers around the world have been tracking the object as it approaches Earth and reporting their observations to the Minor Planet Center.
This "test" of what has become a global asteroid-impact early-warning system is a volunteer project, conceived and organized by NASA-funded asteroid observers and supported by the NASA Planetary Defense Coordination Office (PDCO). As explained by Michael Kelley, program scientist and NASA PDCO lead for the TC4 observation campaign, "Asteroid trackers are using this flyby to test the worldwide asteroid detection and tracking network, assessing our capability to work together in response to finding a potential real asteroid-impact threat."
Previously: NASA Formalizes Planetary Defense Coordination Office to Track Asteroids
NASA and FEMA Conduct Asteroid Threat Response Exercise
Surprise Flyby of Asteroid on January 9, 2017
NASA to Redirect an Asteroid's Moon With Kinetic Impact
Asteroid 2012 TC4 Will Pass Close to Earth on October 12th
4.4 Kilometer Asteroid Safely Passes by Earth (two moons discovered)