Mars collapse. In 2012, it was proposed that Valles Marineris is not just a graben, but a plate boundary where of transverse motion has occurred, making Mars a planet with possibly a two-tectonic plate arrangement. Images from the Thermal Emission Imaging System (THEMIS) aboard NASA's Mars Odyssey orbiter have revealed seven possible cave entrances on the flanks of the volcano Arsia Mons. The caves, named after loved ones of their discoverers, are collectively known as the "seven sisters". Cave entrances measure from wide and they are estimated to be at least deep. Because light does not reach the floor of most
Mars be abandoned, and a vogue for accurate, realist depictions of human colonies on Mars developed, the best known of which may be Kim Stanley Robinson's "Mars" trilogy. Pseudo-scientific speculations about the Face on Mars and other enigmatic landmarks spotted by space probes have meant that ancient civilizations continue to be a popular theme in science fiction, especially in film. Images Videos Cartographic resources Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury. In English, Mars carries a name of the Roman god of war, and is often referred to as