火星上的洞
2020 March 1 A Hole in Mars Image Credit: NASA, JPL, U. Arizona Explanation: What created this unusual hole in Mars? The hole was discovered by chance in 2011 on images of the dusty slopes of Mars’ Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole, shown in representativ...