A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and (101429) 1998 VF31. Many databases, for instance the JPL Small-Body Database (JPL SBDB), only list asteroids with a perihelion greater than 1.3 AU as Mars-crossers. An asteroid with a perihelion less than this is classed as a near-Earth object even though it is crossing the orbit of Mars as well as crossing (or coming near to) that of Earth. Nevertheless, these objects are listed on this page. A grazer is an object with a perihelion below the aphelion of Mars (1.67 AU) but above the Martian perihelion (1.38 AU). The JPL SBDB lists 13,500 Mars-crossing asteroids. Only 18 MCAs are brighter than absolute magnitude (H) 12.5, which typically makes these asteroids with H<12.5 more than 13 km in diameter depending on the albedo. The smallest known MCAs have an absolute magnitude (H) of around 24 and are typically less than 100 meters in diameter. There are over 21,600 known Mars-crossers of which only 5751 have received a MPC number. Earth having more gravity and surface area than Mars attracts more impactors than Mars. Earth is impacted about 20 times more than the Moon, and Mars only gets impacted about 3 to 5 times more than the Moon.
Co-orbital L4 (leading cloud):
(121514) 1999 UJ7 L5 (trailing cloud):
5261 Eureka – the only named Mars trojan (101429) 1998 VF31 (311999) 2007 NS2 (385250) 2001 DH47 (816688) 2011 SC191 2011 UN63 Candidates
2011 SL25
Inner grazers
Inner grazers that are also Earth-crossers or grazers
Mars-crossers that are also Earth-crossers or grazers These objects are not catalogued as Mars-crossers in databases such as the Jet Propulsion Laboratory's online Small-body Database Browser. Instead, they are categorized as Near Earth Objects (NEOs).
Outer grazers
Mars-crossers
See also List of Mercury-crossing minor planets List of Venus-crossing minor planets List of Earth-crossing minor planets List of Jupiter-crossing minor planets List of Saturn-crossing minor planets List of Uranus-crossing minor planets List of Neptune-crossing minor planets
References
External links Jet Propulsion Laboratory Small-Body Database Browser Very Close Approaches (<0.01 AU) of PHAs to Mars 1900–2200 Upcoming Close Approaches (<0.10 AU) of Near-Earth Objects to Mars Planetary Close Encounters for the next 200 years


