What is a minor-planet moon?
Astronomers classify a natural satellite orbiting a minor planet as a minor-planet moon. These systems offer unique insights into physical properties that remain inaccessible through other means.
Questions about Minor-planet moon
Short answers, pulled from the story.
When was the first confirmed asteroid moon discovered?
The first confirmed asteroid moon appeared in 1993 when the Galileo probe spotted Dactyl orbiting 243 Ida within the asteroid belt. This discovery marked the beginning of systematic searches for such companions.
Which minor planet has the most moons currently known?
Pluto and 130 Elektra hold the highest multiplicities currently recorded with five and three moons respectively. Pluto itself has evolved into a sextuple system containing five known moons while 130 Elektra possesses three satellites.
How do scientists determine the mass of a minor planet using its moon?
Determining their orbits allows scientists to estimate the mass and density of the primary body. Optical observations from Earth dominated early attempts to detect satellites before the Hubble Space Telescope era.
What are the main theories explaining how minor-planet moons form?
Scientists propose collisional debris or gravitational capture as the primary mechanisms for forming these moons. Close binaries fit the impact model well while distant binaries likely formed differently unless significant mass loss occurred during the event.