Japan launches ambitious robotic mission to Martian moon Phobos

Japan launched an ambitious $350 million mission to Mars on Monday to study the red planet's two moons in unprecedented detail, dropping a small rover on the largest — Phobos — before the mothership touches down to robotically collect soil samples for return to Earth.

The primary goal of the Martian Moons Exploration mission, or MMX, is to determine whether Phobos and the smaller moon Deimos were created by the impact of a large body early in the solar system's history or whether the two are asteroids that once passed close enough to Mars to be captured by the red planet's gravity.