Who cares about the Face on Mars? It was just an interesting trick of light and shadow—a pareidolia. Now comes a bona fide Martian mystery: pit craters (also known as skylights). Pit craters are thought to be collapse pits into subsurface void spaces. Cave entrances, in other worlds. ;o)
Here are a few:
(A) “Dena,” (B) “Chloe,” (C) “Wendy,” (D) “Annie,” (E) “Abby” (left) and “Nikki,” and (F) “Jeanne.” Arrows signify north and the direction of illumination.Possible Skylight Near Elysium Region (141.317° E, 30.563° N)Pit Crater near Elysium Mons (149.909° E, 23.210° N)Very Large Pit Crater in Daedalia Planum (237.545° E, 19.474° S)Possible Skylight Near Arsia Mons (237.837° E, 2.055° S)Possible Cave on Arsia Mons (238.663° E, 6.355° S)Pit Crater (239.549° E, 1.320° S)Pit South of Arsia Mons (240.021° E, 13.851° S)Incipient Pit Crater in the Arsia Chasmata (240.040° E, 6.518° S)Pit Crater Chain South of Arsia Mons (240.051° E, 14.285° S)Possible Skylight in Arsia Mons Region (240.326° E, 7.850° S)A Pair of Small Pit Craters (240.907° E, 5.691° S)Candidate Cavern Entrance Northeast of Arsia Mons (241.396° E, 5.532° S)Possible Skylight on a Lava Tube Northeast of Arsia Mons (241.900° E, 2.272° S)Dark Rimless Pits in Tharsis Region (247.549° E, 17.263° N)A Giant Cave on a Giant Volcano (248.485° E, 3.735° N)Pit on the Eastern Flank of Pavonis Mons (248.571° E, 0.457° S)Pit or Cave in Tantalus Fossae (257.532° E, 35.030° N)Collapse Pit in Tractus Fossae (259.359° E, 26.143° N)
Most of these features are of a volcanic, rather than impact, origin. Both the Earth and the Moon have similar features, entrances to subsurface caverns and tunnels. What wondrous discoveries await future explorers!