Japan launches spacecraft to moons of Mars

What happened: Japan's space agency launched the MMX mission, a five-year effort with five space agencies to land a robotic prospector and a rover on Phobos, one of Mars' two moons. Key numbers: $578 million mission cost; 5-ton spacecraft; rover moves 1 millimeter per second; 100 days of rover Why it matters: No one has landed on Phobos or Deimos or fetched samples from Mars or its moons. Scientists hope the samples reveal whether the moons formed from an ancient collision with Mars or are captured asteroids, and the findings will help shape future Mars missions, including crewed ones. Coverage: 4 outlets in 24h

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