Minor-planet moon Herculina does not have a significant satellite. There were other similar reports of asteroids having companions (usually referred to as satellites) in the following years. Also, a letter in "Sky & Telescope" magazine at this time pointed to apparently simultaneous impact craters on Earth (for example, the Clearwater Lakes in Quebec), suggesting that these craters were caused by pairs of gravitationally-bound objects. In 1993, the first asteroid moon was confirmed when the Galileo probe discovered the small Dactyl orbiting 243 Ida in the asteroid belt. The second was discovered around 45 Eugenia in 1998. In 2001, 617 Patroclus and its
Lunar craters a new lunar impact crater database similar to Wood and Andersson's, except hers will include all impact craters greater than or equal to five kilometers in diameter and is based on Clementine (spacecraft) images of the lunar surface. The "moon zoo" project within the Zooniverse program aimed to use citizen scientists to map the size and shape of as many craters as possible using data from the NASA Lunar Reconnaissance Orbiter. However, it has since been retired. Craters constitute 95% of all named lunar features. Usually they are named after deceased scientists and other explorers. This tradition comes from Giovanni