NASA just dumped a trove of photos of Mars' dunes, craters, and mountains

NASA's Mars Reconnaissance Orbiter (MRO) has been orbiting the Red Planet for a decade, sending photos back to Earth every month as it goes around. This month's batch contains more than 1,000 photos of Mars' dunes, craters, mountains, ice caps, and other surface features. And they're particularly exciting for a couple of reasons.

Every 26 months, the Sun and Mars are on opposite sides of the Earth's sky — a phenomenon called opposition. During opposition, the MRO has unobstructed communication with Earth for a few weeks and can send huge amounts of data. This year's opposition, which happened in May, also overlapped with Mars' Equinox — a period when the Sun illuminates Mars from the north to the south pole.