Context: In two separate studies in Nature Astronomy, scientists have reported that the Moon has water at places where none had been detected before.

More on the news:

  • One study reports the detection of water on the Moon’s sunlit surface for the first time. 
    • The sunlit surface retaining the water presents a puzzle, since the Moon does not have a thick atmosphere. 
  • The other estimates that the Moon’s dark, shadowy regions, which potentially contain ice, are more widespread than thought earlier.

Water on the Moon - Previous studies: 

  • Chandrayaan-1 mission: In 2009, the Moon Mineralogy Mapper (M3) instrument aboard Chandrayaan-1 found water molecules in the moon’s polar regions. 
  • Other missions: However, based on observations by the Chandrayaan-1 mission, NASA’s Cassini and Deep Impact comet mission, and NASA’s ground-based Infrared Telescope Facility, it was not established that whether the detected molecules were water (H20) or in the form of hydroxyl (OH).

The new discovery:

  • Confirmed by SOFIA: The NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) has confirmed (for the first time) water on the sunlit surface of the Moon.
  • Confirmed water molecules: Discovered in Clavius Crater in the Moon’s southern hemisphere and it is the first time water has been detected on the sunlit side, showing it is not restricted to the shadowy regions.
  • How water reached the moon?: Space rocks carrying small amounts of water could have bombarded the Moon. 
    • Alternatively, the Sun’s solar wind could have carried hydrogen, which then reacted with minerals in the lunar soil to create hydroxyl, which later transformed into water.
  • What’s next?: SOFIA will look for water in additional sunlit locations to learn more about how the water is produced, stored, and moved across the Moon. 
    • Meanwhile, NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) will carry out a mission to create the first water resource maps of the Moon.

Significance of the new discovery: 

  • A precious resource: Apart from being a marker of potential life, water is a precious resource in deep space. 
  • Useful for astronauts: Landing on the Moon, water is necessary not only to sustain life but also for purposes such as generating rocket fuel. 
    • NASA’s Artemis programme plans to send the first woman and the next man to the Moon in 2024. The programme attempts  to establish a sustainable human presence there. 
    • If space explorers can use the Moon’s resources, it means they need to carry less water from Earth.

SOFIA: The flying observatory

  • The Stratospheric Observatory for Infrared Astronomy (SOFIA), is a Boeing 747SP aircraft modified to carry a reflecting telescope. 
  • Flying into the stratosphere at 38,000-45,000 feet puts SOFIA above 99 percent of Earth’s infrared-blocking atmosphere.
  • This allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. 
  • SOFIA is made possible through a partnership between NASA and the German Aerospace Center (DLR).

Image Source: Sky & Telescope