TY - JOUR
T1 - A survey of orbits of co-orbitals of Mars
AU - Connors, Martin
AU - Stacey, Greg
AU - Brasser, Ramon
AU - Wiegert, Paul
N1 - Funding Information:
We wish to thank D.P. Hube for use of space and computing facilities. Initial stages of this work were supported by the Academic Research Fund of Athabasca University. NSERC programs, including the USRA, and the Canada Research Chairs program, have also provided partial support. We thank the Minor Planet Center and University of Pisa for their services in providing orbital elements, and the Jet Propulsion Laboratory for making the Horizons online system available.
PY - 2005/5
Y1 - 2005/5
N2 - Many asteroids with a semimajor axis close to that of Mars have been discovered in the last several years. Potentially some of these could be in 1:1 resonance with Mars, much as are the classic Trojan asteroids with Jupiter, and its lesser-known horseshoe companions with Earth. In the 1990s, two Trojan companions of Mars, 5261 Eureka and 1998 VF31, were discovered, librating about the L5 Lagrange point, 60° behind Mars in its orbit. Although several other potential Mars Trojans have been identified, our orbital calculations show only one other known asteroid, 1999 UJ7, to be a Trojan, associated with the L4 Lagrange point, 60°ahead of Mars in its orbit. We further find that asteroid 36017 (1999 ND43) is a horseshoe librator, alternating with periods of Trojan motion. This asteroid makes repeated close approaches to Earth and has a chaotic orbit whose behavior can be confidently predicted for less than 3000 years. We identify two objects, 2001 HW15 and 2000 TG2, within the resonant region capable of undergoing what we designate "circulation transition", in which objects can pass between circulation outside the orbit of Mars and circulation inside it, or vice versa. The eccentricity of the orbit of Mars appears to play an important role in circulation transition and in horseshoe motion. Based on the orbits and on spectroscopic data, the Trojan asteroids of Mars may be primordial bodies, while some co-orbital bodies may be in a temporary state of motion.
AB - Many asteroids with a semimajor axis close to that of Mars have been discovered in the last several years. Potentially some of these could be in 1:1 resonance with Mars, much as are the classic Trojan asteroids with Jupiter, and its lesser-known horseshoe companions with Earth. In the 1990s, two Trojan companions of Mars, 5261 Eureka and 1998 VF31, were discovered, librating about the L5 Lagrange point, 60° behind Mars in its orbit. Although several other potential Mars Trojans have been identified, our orbital calculations show only one other known asteroid, 1999 UJ7, to be a Trojan, associated with the L4 Lagrange point, 60°ahead of Mars in its orbit. We further find that asteroid 36017 (1999 ND43) is a horseshoe librator, alternating with periods of Trojan motion. This asteroid makes repeated close approaches to Earth and has a chaotic orbit whose behavior can be confidently predicted for less than 3000 years. We identify two objects, 2001 HW15 and 2000 TG2, within the resonant region capable of undergoing what we designate "circulation transition", in which objects can pass between circulation outside the orbit of Mars and circulation inside it, or vice versa. The eccentricity of the orbit of Mars appears to play an important role in circulation transition and in horseshoe motion. Based on the orbits and on spectroscopic data, the Trojan asteroids of Mars may be primordial bodies, while some co-orbital bodies may be in a temporary state of motion.
KW - Co-orbital asteroid
KW - Horseshoe orbit
KW - Mars Trojan
KW - Three-body problem
UR - http://www.scopus.com/inward/record.url?scp=16244394060&partnerID=8YFLogxK
U2 - 10.1016/j.pss.2004.12.004
DO - 10.1016/j.pss.2004.12.004
M3 - Journal Article
AN - SCOPUS:16244394060
SN - 0032-0633
VL - 53
SP - 617
EP - 624
JO - Planetary and Space Science
JF - Planetary and Space Science
IS - 6
ER -