Earth's first Trojan Asteroid discovered

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 28th, 2011 edition 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 follow-up observations made with ground-based telescopes, all back in October 2010. The team confirmed the Trojan nature of the asteroid using 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 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.

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

The complex orbit of 2010 TK7 with respect to Earth can be seen on the cover of Nature magazine July 28, 2011 issue. More figures and animations showing 2010 TK7 motion are available on Paul Wiegert's web site here.

Canada-France-Hawaii Telescope: Christian Veillet - Tel: +1 808-938-3905 - email:

Athabasca University: Martin Connors - email:
University of Western Ontario: Paul Wiegert - email:

The complete article is available on Nature's website:
Martin Connors, Paul Wiegert, & Christian Veillet, 2011. Earth's Trojan asteroid

University of Western Ontario web page is here.
NASA/WISE web page is here.

April 2011 CFHT observations of 2010 TK7 (get the file)

COD 568
MEA C. Veillet
TEL  CFHT 3.6-m + MegaCam
ACK 11AD91
     K10T07K  C2011 04 28.61447 21 45 55.61 -05 55 45.0               r      568
     K10T07K  C2011 04 28.61712 21 45 56.05 -05 55 46.0               r      568
     K10T07K  C2011 04 28.62508 21 45 57.51 -05 55 49.5               r      568
     K10T07K  C2011 04 29.61795 21 48 56.81 -06 02 58.6               r      568
     K10T07K  C2011 04 29.62059 21 48 57.28 -06 02 59.6          23.2 r      568
     K10T07K  C2011 04 29.62323 21 48 57.75 -06 03 00.6               r      568