Mark your calendars: NASA's Artemis program to return to the Moon could launch its first uncrewed test flight as soon as August 29, the agency said Wednesday.

Artemis-1 is the first in a series of missions as the United States seeks to return humans to the Moon, build a sustained presence there, and use the lessons gained to plan a trip to Mars sometime in the 2030s.

Using data collected over two decades ago, scientists from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, have compiled the first complete map of hydrogen abundances on the Moon's surface. The map identifies two types of lunar materials containing enhanced hydrogen and corroborates previous ideas about lunar hydrogen and water, including findings that water likely played a role in the Moon's original magma-ocean formation and solidification.

APL's David Lawrence, Patrick Peplowski and Jack Wilson, along with Rick Elphic from NASA Ames Research Center, used orbital neutron data from the Lunar Prospector mission to build their map. The probe, which was deployed by NASA in 1998, orbited the Moon for a year and a half and sent back the first direct evidence of enhanced hydrogen at the lunar poles, before impacting the lunar surface.