Earth’s First Trojan Asteroid Discovered

2010 TK7 is seen as a speck of light in the center of this image, which is the addition of three individual exposures taken with the MegaCam camera at CFHT. The telescope was tracking the motion of the asteroid, leading to the image of the stars to be trailed. With three exposures added, stars end up looking like a broken trail. Image by C. Veillet 2011 – (c)CFHT

Martin Connors (Athabasca University, Canada), Christian Veillet (Canada-France-Hawaii Telescope, Hawaii), and Paul Wiegert (University of Western Ontario, Canada) have confirmed the existence of the first known Trojan Asteroid associated with Earth. The discovery is highlighted in the July 28, 2011, issue of Nature magazine.

The Trojan, called 2010 TK7, was first tentatively identified by the team from 2010 TK7 discovery observations made with the NASA’s Wide-field Infrared Survey Explorer (WISE) satellite and the follow-up observations made with ground-based telescopes, all back in October 2010. The team confirmed the Trojan nature of the asteroid using new observations they obtained using the Canada-France-Hawaii Telescope in April 2011.

Previously, Trojans were known to exist associated with Jupiter, Neptune, and Mars. 2010 TK7 proves that they can also be found associated to Earth. How long can they keep their Trojan nature on Earth’s orbit is still unclear, but 2010 TK7 is stable for at least ten thousand years. More Earth Trojans are likely to be found in the coming years, allowing for a better understanding of their dynamics and the characteristics of their population.

Images of 2010 TK7 observed at CFHT, with the corresponding astrometric data and links to images and animations, as well as a link to the Nature paper, can be found here: http://www.cfht.hawaii.edu/en/news/EarTro/

Contact:
Dr. Christian Veillet
Executive Director, CFHT
+1 808 938 3905
veillet@cfht.hawaii.edu