The moon may have been siphoning water from Earth’s atmosphere for billions of years, storing it up as ice deep inside craters, a new study has found.
Research by the University of Alaska Fairbanks suggests that ions making up water are pulled in by the moon as it passes through part of Earth’s magnetosphere.
This adds to other suspected methods, including bombardment from asteroids 3.5 billion years ago, and solar wind delivering oxygen and hydrogen ions.
The team estimate there are up to 840 cubic miles of surface permafrost or subsurface liquid water on the moon that escaped from Earth’s atmosphere – enough to fill North America’s Lake Huron – the eighth largest lake on the planet.
The work, by lead author, professor Gunther Kletetschka, adds to a growing body of research about water at the moon’s north and south poles, prime targets for a base.
The moon may have been siphoning water from Earth’s atmosphere for billions of years, storing it up as ice deep inside craters, a new study has found
Finding water is key to NASA’s Artemis project, the planned long-term human presence on the moon. NASA plans to send humans back to the moon this decade.
‘As NASA’s Artemis team plans to build a base camp on the moon’s south pole, the water ions that originated many eons ago on Earth can be used in the astronauts’ life support system,’ Kletetschka said.
Researchers based their estimate, of 840 cubic miles of water, on the lowest volume model calculation – one per cent of Earth’s atmospheric escape reaching the moon.
A majority of the lunar water is generally believed to have been deposited by asteroids and comets that collided with the moon.
Research by the University of Alaska Fairbanks suggests that ions making up water are pulled in by the moon as it passes through part of Earth’s magnetosphere
This adds to other suspected methods, including bombardment from asteroids 3.5 billion years ago, and solar wind delivering oxygen and hydrogen ions
Most was during a period known as the Late Heavy Bombardment, a period about 3.5 billion years ago when the solar system was a billion years old, and the early inner planets sustained unusually heavy impact from asteroids.
As well as the ancient asteroid and comet source of water on the moon, scientists also suggest solar wind could be a source.
Ice on the moon! Water buried in lunar rocks ‘that could one day sustain a human colony’ was likely preserved by an ancient magnetic field
Frozen water buried in rocks on the lunar surface may have been protected from intense sunlight by an ancient magnetic field surrounding the moon, study shows.
Once extracted from rocks, the water could one day be used to sustain future human settlements, experts said – providing both something to drink and ingredients for fuel.
A number of spacecraft have seen evidence of ice deep inside craters at the polar regions of the moon, where temperatures can drop to -418F due to sunlight’s inability to penetrate inside the dark pits.
However, solar winds can get inside, breaking down the ice formations molecule-by-molecule – which is why scientists have long been unclear how the moon’s ice has remained in place millions of years after arriving on a comet.
A new study by a team from the University of Arizona, however, suggests that the water is preserved as a result of ‘magnetic anomalies’ surrounding certain craters, which are the remnants of the ancient magnetic field that once covered the moon.
Speaking to Science, the team say the anomalies ‘deflect the solar wind,’ and ‘could be quite significant in shielding the permanently shadowed regions.’
The solar wind carries oxygen and hydrogen ions, which may have combined and been deposited on the moon as water molecules.
In this new study, the team suggest that, in addition to solar wind carrying ions, and ancient bombardment, water arrived from the Earth’s atmosphere.
Kletetschka and his colleagues suggest hydrogen and oxygen ions are driven into the moon when it passes through the tail of the Earth’s magnetosphere, which it does on five days of the moon’s monthly trip around the planet.
The magnetosphere is the teardrop-shaped bubble created by Earth’s magnetic field that shields the planet from much of the continual stream of charged solar particles.
Recent measurements from multiple space agencies, including NASA, ESA, JAXA and ISRO, revealed significant numbers of water-forming ions present during the moon’s transit through this part of the magnetosphere.
These ions have slowly accumulated since the Late Heavy Bombardment, increasing over 3.5 billion years each time the moon passes through the magnetosphere.
The presence of the moon in the magnetosphere’s tail, called the magnetotail, temporarily affects some of Earth’s magnetic field lines — those that are broken and which simply trail off into space for many thousands of miles.
Not all of Earth’s field lines are attached to the planet at both ends, as some have only one attachment point.
The moon’s presence in the magnetotail causes some of these broken field lines to reconnect with their opposing broken counterpart.
When that happens, hydrogen and oxygen ions that had escaped Earth rush to those reconnected field lines and are accelerated back toward Earth.
The paper’s authors suggest many of those returning ions hit the passing moon, which has no magnetosphere of its own to repel them.
‘It is like the moon is in the shower – a shower of water ions coming back to Earth, falling on the moon’s surface,’ Kletetschka said.
The ions then combine to form the lunar permafrost, and some is driven below the surface where it exists as liquid water.
The findings have been published in the journal Scientific Reports.
NASA will land the first woman and first person of color on the moon in 2025 as part of the Artemis mission
Artemis was the twin sister of Apollo and goddess of the moon in Greek mythology.
NASA has chosen her to personify its path back to the moon, which will see astronauts return to the lunar surface by 2025 – including the first woman and the next man.
Artemis 1, formerly Exploration Mission-1, is the first in a series of increasingly complex missions that will enable human exploration to the moon and Mars.
Artemis 1 will be the first integrated flight test of NASA’s deep space exploration system: the Orion spacecraft, Space Launch System (SLS) rocket and the ground systems at Kennedy Space Center in Cape Canaveral, Florida.
Artemis 1 will be an uncrewed flight that will provide a foundation for human deep space exploration, and demonstrate our commitment and capability to extend human existence to the moon and beyond.
During this flight, the spacecraft will launch on the most powerful rocket in the world and fly farther than any spacecraft built for humans has ever flown.
It will travel 280,000 miles (450,600 km) from Earth, thousands of miles beyond the moon over the course of about a three-week mission.
Artemis 1, formerly Exploration Mission-1, is the first in a series of increasingly complex missions that will enable human exploration to the moon and Mars. This graphic explains the various stages of the mission
Orion will stay in space longer than any ship for astronauts has done without docking to a space station and return home faster and hotter than ever before.
With this first exploration mission, NASA is leading the next steps of human exploration into deep space where astronauts will build and begin testing the systems near the moon needed for lunar surface missions and exploration to other destinations farther from Earth, including Mars.
The will take crew on a different trajectory and test Orion’s critical systems with humans aboard.
Together, Orion, SLS and the ground systems at Kennedy will be able to meet the most challenging crew and cargo mission needs in deep space.
Eventually NASA seeks to establish a sustainable human presence on the moon by 2028 as a result of the Artemis mission.
The space agency hopes this colony will uncover new scientific discoveries, demonstrate new technological advancements and lay the foundation for private companies to build a lunar economy.