Erik Hauri, scientist who found water on the moon, dies at 52

When early astronomers gazed up at the moon, they mistook its dark patches for seas. By the time astronaut Neil Armstrong stepped onto the Sea of Tranquility in 1969, scientists knew it was nothing but terra firma.

Most researchers concluded that the moon was “bone dry,” a celestial desert devoid of water or ice. But in a set of papers published beginning in 2008, geochemist Erik Hauri helped demonstrate that water existed on the moon after all — and that the moon’s interior might contain as much water as the Mediterranean Sea.