A minor-planet moon is an astronomical object that orbits a minor planet as its natural satellite. As of February 2019, there are 352 minor planets known or suspected to have moons. Discoveries of minor-planet moons are important because the determination of their orbits provides estimates on the mass and density of the primary, allowing insights of their physical properties that is generally not otherwise possible.
624 Hektor is the largest Jupiter trojan and the namesake of the Hektor family, with a highly elongated shape equivalent in volume to a sphere of approximately 225 to 250 kilometers diameter. It was discovered on 10 February 1907, by astronomer August Kopff at Heidelberg Observatory in southwest Germany, and named after the Trojan prince Hector, from Greek mythology. It has one small 12-kilometer sized satellite, Skamandrios, discovered in 2006.
Steven Jeffrey Ostro was an American scientist specializing in radar astronomy. He worked at NASA's Jet Propulsion Laboratory. Ostro led radar observations of numerous asteroids, as well as the moons of Jupiter and Saturn, Saturn's rings, and Mars and its satellites. As of May 2008, Ostro and his collaborators had detected 222 near-Earth asteroids and 118 main belt objects with radar. He died December 15, 2008 due to complications related to cancer. He has been remembered fondly by his colleagues for both his personal and professional contributions.
Antiope is a double asteroid in the outer asteroid belt. It was discovered on October 1, 1866, by Robert Luther. In 2000, it was found to consist of two almost-equally-sized bodies orbiting each other. At average diameters of about 88 km and 84 km, both components are among the 500 largest asteroids. Antiope is a member of the Themis family of asteroids that share similar orbital elements.
4486 Mithra, provisional designation 1987 SB, is an eccentric asteroid and suspected contact-binary, classified as near-Earth object and potentially hazardous asteroid, approximately 2 kilometers in diameter. It belongs to the Apollo group of asteroids and is a relatively slow rotator.
Nysa is a large and very bright main-belt asteroid, and the brightest member of the Nysian asteroid family. It is classified as a rare class E asteroid and is probably the largest of this type.
617 Patroclus, provisional designation 1906 VY is a binary Jupiter trojan approximately 140 kilometers in diameter. It was discovered on 17 October 1906, by astronomer August Kopff at the Heidelberg Observatory in Germany. The asteroid was named after Patroclus from Greek mythology. It was the second trojan to be discovered and the only member of the Trojan camp named after a Greek character. The dark D-type asteroid is also slow rotator and one of the largest Jupiter trojans. Patroclus is one of five Jovian asteroids targeted by the Lucy space probe to be visited in 2033. In 2001, a moon – later named Menoetius, and slightly smaller than its primary – was discovered. It was the first discovery of a binary asteroid among the Jupiter trojans.
A contact binary is a small Solar System body such as a minor planet or a comet, that is composed of two bodies that have gravitated toward each other until they touch, resulting in a bilobated, peanut-like overall shape. Contact binaries are often rubble piles but distinct from real binary systems such as binary asteroids. The term is also used for stellar contact binaries.
(185851) 2000 DP107 is a sub-kilometer sized asteroid, classified as potentially hazardous asteroid and near-Earth object of the Apollo group that is notable because it provided evidence for binary asteroids in the near-Earth population.
4450 Pan, provisional designation 1987 SY, is a highly eccentric asteroid and contact binary, classified as a potentially hazardous asteroid and near-Earth object of the Apollo group, approximately 1.1 kilometers in diameter.
The Asteroid Impact and Deflection Assessment (AIDA) mission is a proposed pair of space probes which would study and demonstrate the kinetic effects of crashing an impactor spacecraft into an asteroid moon. The mission is intended to test whether a spacecraft could successfully deflect an asteroid on a collision course with Earth. The concept proposes two spacecraft: Hera would orbit the asteroid, and Double Asteroid Redirection Test (DART) would impact its moon. Besides the observation of the change of orbital parameters of the asteroid moon, the observation of the plume, the crater, and the freshly exposed material will provide unique information for asteroid deflection, science and mining communities.
(388188) 2006 DP14, provisional designation 2006 DP14, is a sub-kilometer sized, peanut-shaped asteroid on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. This contact binary was discovered on 23 February 2006, by astronomers of the LINEAR program at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. On 10 February 2014, it passed 6.25 lunar distances from Earth. The asteroid is approximately 400 meters in diameter and has a rotation period of 5.77 hours.
(85989) 1999 JD6 is an Aten asteroid, near-Earth object, and potentially hazardous object in the inner Solar System that makes frequent close approaches to Earth and Venus. On the Earth approach in 2015, it was observed by the Goldstone Solar System Radar and found to be a contact binary with the largest axis approximately 2 kilometers wide, and each lobe about 200–300 meters large. Although 1999 JD6 in its current orbit never passes closer than 0.047 AU to Earth, it is listed as a potentially hazardous object because it is large and might pose a threat in the future.
VFTS 352 is a contact binary star system 160,000 light-years (49,000 pc) away in the Tarantula Nebula, which is part of the Large Magellanic Cloud. It is the most massive and earliest spectral type overcontact system known.
2014 JO25 is an asteroid. It was discovered in May 2014 by astronomers at the Catalina Sky Srvey near Tucson, Arizona - a project of NASA's NEO (Near Earth Object) Observations Program in collaboration with the University of Arizona.
(300163) 2006 VW139, provisional designations 2006 VW139 and P/2006 VW139, as well as periodic cometary number 288P, is a kilometer-sized asteroid from the outer regions of the asteroid belt and the first "binary main-belt comet" ever discovered.
