Irregular moon Irregular moon In astronomy, an irregular moon, irregular satellite or irregular natural satellite is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They have been captured by their parent planet, unlike regular satellites, which formed in orbit around them. As of July 2018, 125 irregular moons are known, orbiting all four of the outer planets (Jupiter, Saturn, Uranus and Neptune). The largest of each planet are Himalia of Jupiter, Phoebe of Saturn, Sycorax of Uranus, and Triton of Neptune. It is currently thought that the irregular satellites were captured from heliocentric orbits near their current
The Ganymede Club The Ganymede Club The Ganymede Club is a science fiction novel by American writer Charles Sheffield, published in 1995. A mystery and a thriller, the story unravels in the same universe that Sheffield imagined in "Cold as Ice". Shortly after humanity begins colonisation of the solar system, a trade war sets off vicious civil war that kills billions. The book received favorable reviews from "Library Journal" and "Kirkus Reviews", as well as in the science-fiction press. It was ranked #14 in SF novels in the 1996 "Locus" awards. The novel has been translated into Italian and was published as "Memoria