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 Base Camp its moons (Deimos and Phobos), and serve as a proving ground in preparing humans for future missions to the Martian surface. The concept was published in May 2016 by Lockheed Martin, and it is a design for a spacecraft for carrying humans to Mars orbit and conducting operations in Mars orbit. Mars Base Camp harnesses many NASA technologies in development, or technology goals at the time of the 2010s. In September 2017, the plan was updated including a concept for a reusable crewed shuttle called MADV (Mars Ascent Descent Vehicle), which would connect to the MBC Mars space station. Mars