NASA’s SOFIA Discovers Water on Sunlit Surface of Moon


Oct. 26, 2020 RELEASE 20-105

Image of Moon and illustration depicting water trapped in lunar soil and NASA’s Stratospheric Observatory for Infrared Astronomy

This illustration highlights the Moon’s Clavius Crater with an illustration depicting water trapped in the lunar soil there, along with an image of NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) that found sunlit lunar water.Credits: NASA/Daniel Rutter

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) has confirmed, for the first time, water on the sunlit surface of the Moon. This discovery indicates that water may be distributed across the lunar surface, and not limited to cold, shadowed places.

SOFIA has detected water molecules (H2O) in Clavius Crater, one of the largest craters visible from Earth, located in the Moon’s southern hemisphere. Previous observations of the Moon’s surface detected some form of hydrogen, but were unable to distinguish between water and its close chemical relative, hydroxyl (OH). Data from this location reveal water in concentrations of 100 to 412 parts per million – roughly equivalent to a 12-ounce bottle of water – trapped in a cubic meter of soil spread across the lunar surface. The results are published in the latest issue of Nature Astronomy.

“We had indications that H2O – the familiar water we know – might be present on the sunlit side of the Moon,” said Paul Hertz, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters in Washington. “Now we know it is there. This discovery challenges our understanding of the lunar surface and raises intriguing questions about resources relevant for deep space exploration.”

As a comparison, the Sahara desert has 100 times the amount of water than what SOFIA detected in the lunar soil. Despite the small amounts, the discovery raises new questions about how water is created and how it persists on the harsh, airless lunar surface.

Water is a precious resource in deep space and a key ingredient of life as we know it. Whether the water SOFIA found is easily accessible for use as a resource remains to be determined. Under NASA’s Artemis program, the agency is eager to learn all it can about the presence of water on the Moon in advance of sending the first woman and next man to the lunar surface in 2024 and establishing a sustainable human presence there by the end of the decade.

SOFIA’s results build on years of previous research examining the presence of water on the Moon. When the Apollo astronauts first returned from the Moon in 1969, it was thought to be completely dry. Orbital and impactor missions over the past 20 years, such as NASA’s Lunar Crater Observation and Sensing Satellite, confirmed ice in permanently shadowed craters around the Moon’s poles. Meanwhile, several spacecraft – including the Cassini mission and Deep Impact comet mission, as well as the Indian Space Research Organization’s Chandrayaan-1 mission – and NASA’s ground-based Infrared Telescope Facility, looked broadly across the lunar surface and found evidence of hydration in sunnier regions. Yet those missions were unable to definitively distinguish the form in which it was present – either H2O or OH.

“Prior to the SOFIA observations, we knew there was some kind of hydration,” said Casey Honniball, the lead author who published the results from her graduate thesis work at the University of Hawaii at Mānoa in Honolulu. “But we didn’t know how much, if any, was actually water molecules – like we drink every day – or something more like drain cleaner.”

Scientists using NASA’s telescope on an airplane, the Stratospheric Observatory for Infrared Astronomy, discovered water on a sunlit surface of the Moon for the first time. SOFIA is a modified Boeing 747SP aircraft that allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. Molecular water, H2O, was found in Clavius Crater, one of the largest craters visible from Earth in the Moon’s southern hemisphere. This discovery indicates that water may be distributed across the lunar surface, and not limited to cold, shadowed places.Credits: NASA/Ames Research Center

SOFIA offered a new means of looking at the Moon. Flying at altitudes of up to 45,000 feet, this modified Boeing 747SP jetliner with a 106-inch diameter telescope reaches above 99% of the water vapor in Earth’s atmosphere to get a clearer view of the infrared universe. Using its Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST), SOFIA was able to pick up the specific wavelength unique to water molecules, at 6.1 microns, and discovered a relatively surprising concentration in sunny Clavius Crater.

“Without a thick atmosphere, water on the sunlit lunar surface should just be lost to space,” said Honniball, who is now a postdoctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Yet somehow we’re seeing it. Something is generating the water, and something must be trapping it there.”

Several forces could be at play in the delivery or creation of this water. Micrometeorites raining down on the lunar surface, carrying small amounts of water, could deposit the water on the lunar surface upon impact. Another possibility is there could be a two-step process whereby the Sun’s solar wind delivers hydrogen to the lunar surface and causes a chemical reaction with oxygen-bearing minerals in the soil to create hydroxyl. Meanwhile, radiation from the bombardment of micrometeorites could be transforming that hydroxyl into water.

How the water then gets stored – making it possible to accumulate – also raises some intriguing questions. The water could be trapped into tiny beadlike structures in the soil that form out of the high heat created by micrometeorite impacts. Another possibility is that the water could be hidden between grains of lunar soil and sheltered from the sunlight – potentially making it a bit more accessible than water trapped in beadlike structures.

For a mission designed to look at distant, dim objects such as black holes, star clusters, and galaxies, SOFIA’s spotlight on Earth’s nearest and brightest neighbor was a departure from business as usual. The telescope operators typically use a guide camera to track stars, keeping the telescope locked steadily on its observing target. But the Moon is so close and bright that it fills the guide camera’s entire field of view. With no stars visible, it was unclear if the telescope could reliably track the Moon. To determine this, in August 2018, the operators decided to try a test observation.

“It was, in fact, the first time SOFIA has looked at the Moon, and we weren’t even completely sure if we would get reliable data, but questions about the Moon’s water compelled us to try,” said Naseem Rangwala, SOFIA’s project scientist at NASA’s Ames Research Center in California’s Silicon Valley. “It’s incredible that this discovery came out of what was essentially a test, and now that we know we can do this, we’re planning more flights to do more observations.”

SOFIA’s follow-up flights will look for water in additional sunlit locations and during different lunar phases to learn more about how the water is produced, stored, and moved across the Moon. The data will add to the work of future Moon missions, such as NASA’s Volatiles Investigating Polar Exploration Rover (VIPER), to create the first water resource maps of the Moon for future human space exploration.

In the same issue of Nature Astronomy, scientists have published a paper using theoretical models and NASA’s Lunar Reconnaissance Orbiter data, pointing out that water could be trapped in small shadows, where temperatures stay below freezing, across more of the Moon than currently expected. The results can be found here.   

“Water is a valuable resource, for both scientific purposes and for use by our explorers,” said Jacob Bleacher, chief exploration scientist for NASA’s Human Exploration and Operations Mission Directorate. “If we can use the resources at the Moon, then we can carry less water and more equipment to help enable new scientific discoveries.”

SOFIA is a joint project of NASA and the German Aerospace Center. Ames manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California.

B-roll footage related to this finding is available at:

Participate in a Reddit Ask Me Anything on our Moon exploration activities at 1 p.m. EDT Tuesday, Oct. 27:

Learn more about SOFIA at:


0 0 votes
Article Rating
Newest Most Voted
Inline Feedbacks
View all comments
Carl Friis-Hansen
October 27, 2020 3:13 am

“It’s incredible that this discovery came out of what was essentially a test, and now that we know we can do this, we’re planning more flights to do more observations.”

Thinking and doing outside the box is often interesting.

Reply to  Carl Friis-Hansen
October 27, 2020 7:14 am

Data from this location reveal water in concentrations of 100 to 412 parts per million – roughly equivalent to a 12-ounce bottle of water – trapped in a cubic meter of soil spread across the lunar surface.

What a confused , contorted way to “simply” ppm.

How many Olympic sized swimming pools is that ? All I can relate to in science is swimming pools and football pitches.

Funny how we went from no water on moon, no water on Mars, no water except in comets to : water everywhere we look.

Another possibility is that the water could be hidden between grains of lunar soil and sheltered from the sunlight

Still does not explain why is does not evaporate in the near vacuum, or is there a lunar atmosphere hiding between grains of lunar soil too?

The discovery is interesting the presser is garbage. Shame they can’t find someone who understands science instead of freshmen media studies undergrads.

October 27, 2020 3:36 am

How does NASA keep a straight face? Their carbon footprint is staggering. Oh that’s right the shocking evil production of CO2 by NASA doesn’t count. Lefty scientists are exempt its just us that has to change.

Ron Long
October 27, 2020 3:48 am

Interesting finding on our moon. The NASA article suggests ways the water may have gotten onto the lunar surface, mostly invoking meteorite transport. The abundance of water in deep-origin garnet eclogite inclusions here on earth suggests some water may exist as an initial part of the cooling core of a molten body, whether planet or moon. Some igneous petrology scientists suggest the earth examples may be due to deep transport by subduction events, but these eclogites are from the mantle and are not likely participants in subduction and subsequent melting processes. Therefore, it is entirely possible that lunar water is associated with natural crystallization processes, just as is possible here on earth. If astronauts are going to extract water from rocks they better have a phaser with them. I see some are available on E-bay.

October 27, 2020 3:57 am

The should add Mars to the to do list while we are still just past conjunction.

Captain Climate
October 27, 2020 4:44 am

I’m guessing they’re going to need a lot of nuclear power to process that soil and extract the water. About the same concentration of water by volume was CO2 in our atmosphere.

October 27, 2020 4:50 am

“NASA’s Stratospheric Observatory for Infrared Astronomy- acronym (SOFIA)”
to ancient Greeks: originally technical skill. later wisdom
to Christians: (divine) wisdom
to Gnostics: soul
other: capital of Bulgaria.
Hagia (Aya) Sophia, Istanbul, Turkey: Early Christian cathedral in the Constantinople, the capital of the Eastern Roman Empire built in the sixth century. In 1453 with the Ottoman conquest of Constantinople converted to a mosque. In 1934, after the Ataturk’s revolution Turkish government secularized the Hagia Sofia and turned it into a museum .
On July 10 of this year, the Turkish President Recep Tayyip Erdoğan signed a decree, despite world-wide Christians’ protests, to convert Hagia Sophia back into a mosque.
and finally:
Sophist- was a teacher in ancient Greece in the fifth and fourth centuries BC. Sophists specialized in one or more subject areas, such as philosophy, rhetoric, music, athletics, and mathematics (wiki)
sophistry- The use of clever but false arguments, especially with the intention of deceiving (Oxford dic).

Ed Fix
October 27, 2020 5:04 am

Wasn’t Clavius where they found the black monolith in 2001 or so?

October 27, 2020 5:10 am

So, they detected an infrared wavelength using a detector mounted in an airplane. That means it came from a lunar area visible from the Earth. How do they know that signal wasn’t the result of Earthshine?

Mark - Helsinki
October 27, 2020 5:34 am

Solar wind creates water when it hits star dust

It’s not even remotely surprising that there is some water there. There’s not much I’d imagine, but some, which is enough to at least say with certainty there is water there.

Not much else

Reply to  Mark - Helsinki
October 27, 2020 7:35 am

Protons hitting silicon creates water?

Erast Van Doren
Reply to  MarkW
October 27, 2020 1:11 pm

Lunar surface is roughly 43 percent oxygen.

Paul Johnson
October 27, 2020 5:46 am

“When the Apollo astronauts first returned from the Moon in 1969, it was thought to be completely dry.”
How dry were the Apollo moon rocks? If SOFIA can identify water in lunar soil from a quarter-million miles away, shouldn’t NASA find it in the samples they have had in hand for 50 years?

Reply to  Paul Johnson
October 27, 2020 5:58 am

The Moon rocks were very dry. As opposed to Earth, there was very little in the way of hydrated mineralogy.

Paul Johnson
Reply to  David Middleton
October 27, 2020 8:01 am

So is SOFIA seeing something in lunar soil that wasn’t there in the ground truth samples?

Paul Johnson
Reply to  Paul Johnson
October 27, 2020 1:52 pm

Update from the NASA “Ask Me Anything” Reddit event:
“The instrumentation used to analyze the Apollo samples in the 1970s was not capable of resolving the tiny water molecules, and so at the time we thought the Moon was very dry. Over the last 5 decades, instrumentation has advanced significantly, enabling scientists to reanalyze Apollo samples in the lab as well as use advanced telescopes like SOFIA to resolve water in extremely small quantities.”
Not a completely satisfying answer, but it seems that the SOFIA data is providing a wide-area assessment of something that has shown up locally in re-analysis of Apollo soil samples.

Reply to  Paul Johnson
October 27, 2020 3:46 pm

If the Maria and highlands regoliths sampled by the Apollo missions did have traces of water in the interstitial pore space, it wouldn’t have been distinguishable after transport to Earth.

The water detected by SOFIA consists of traces of liquid water in the regolith, not hydrated mineralogy of the rocks.

Reply to  Paul Johnson
October 27, 2020 3:39 pm

No. The Apollo missions didn’t land in craters.

Reply to  David Middleton
October 27, 2020 11:25 am

David Middleton
October 27, 2020 at 5:58 am

Yes, ground truth would seem to not support these findings.

I suspect this just a blatant ploy by NASA to justify their existence and gross failure to keep up with SpaceX technology and also to support Sophia which I think has recently been under threat of defunding.

They should ditch the SLS, cut their losses and embrace renewable rockets…isn’t that the buzzword these days? The Russians are looking at reusable rockets and I’m sure the Chinese are not sitting on their hands. NASA is going to be left out of the game soon. The taxpayers should be demanding this from NASA. Or maybe forget rockets altogether and concentrate on manned landers, probes, etc. which they (or JPL) does well.

Reply to  Alastair Brickell
October 27, 2020 3:49 pm

It’s something totally different. SOFIA isn’t detecting hydrated mineralogy of the rocks. It’s detecting traces of liquid water in the regolith (dirt).

Jim Whelan
October 27, 2020 7:40 am

1% of the amount of water in the Sahara desert and the media portrays this as if it’s flowing in great quantity. And “sheltering the water from sunlight isn’t enough. At the practically zero pressure of the moon’s atmosphere the water will evaporate at any temperature. So to be in liquid form it must be encapsulated. Little is said about exactly what is being detected but molecular bonding with minerals could be a possibility.

Reply to  Jim Whelan
October 27, 2020 2:37 pm

Even here on Earth, ice sublimates directly to water vapor at higher elevations in the right conditions.

Rich Davis
Reply to  brians356
October 27, 2020 5:03 pm

Also in my back yard at 81m above sea level on a cold dry sunny day.

Dudley Horscroft
October 27, 2020 8:44 am

The samples collected were in sunlight. So all the water in them would have been evaporated.

The steam (evaporated water) would naturally have condensed after sunset. So it is feasible that shaded grains of sand/dust/gravel/rocks would have still been very cold even though Clavius as a whole was illuminated. And the water detected would likely have been just boiling off enough to trigger the SOFIA detectors.

Gordon A. Dressler
October 27, 2020 9:23 am

There is the statement in the above article that: “NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) has confirmed, for the first time, water on the sunlit surface of the Moon.”

That “first time” claim is very debatable. According to Wikipedia (,NASA%20on%20October%2026%2C%202020. ):
“On 18 August 1976, the Soviet Luna 24 probe landed at Mare Crisium, took samples from the depths of 118, 143, and 184 cm of the lunar regolith, and then took them to Earth. In February 1978, it was published that laboratory analysis of these samples shown they contained 0.1% water by mass. Spectral measurements shown minima near 3, 5, and 6 µm, distinctive valence-vibration bands for water molecules, with intensities two or three times larger than the noise level.”

Mare Crisium is just visible from Earth with the naked eye as a small dark spot on the edge of the Moon’s face, so it qualifies to be “on the sunlit surface of the Moon”.

And note that the above article cites SOFIA detection of water at concentrations up to 412 parts per million, or about .04 %, which is not inconsistent with the Luna 24 actual physical measurements of 0.1% water by mass.

For some reason, the above article does not make mention of the Soviet Luna 24 data that clearly indicated the presence of water on the sunlit surface of the Moon . . . more than 40 years ago.

But facts do matter.

Gordon A. Dressler
October 27, 2020 10:14 am

Regarding the very low concentration of water (100 to 412 ppm as measured by SOFIA) seen in the Moon’s sunlit surface:

What we don’t know is what percentage of this water is being continuously “boiled off” (sublimated) from the sunlit side and then travels, via vapor diffusion, around to “freeze out” (condense as ice) on the temporarily shadowed surfaces of the Moon. Since almost all of the Moon’s surface—excluding just those cratered areas near the Moon’s poles that are in permanent shadow—experiences a repeating pattern of about 13.6 Earth days of sunlight followed by 13.6 Earth days of darkness (neglecting Earthshine), it is possible that the Moon has a kind of hydrological cycle of its own.

Matthew Bergin
October 27, 2020 10:21 am

I was under the impression that the entire surface of the moon is sunlit at one time or another so shouldn’t the statement be ” We have found traces of water on the surface of the moon”?🤷‍♂️🙄🙄😉

October 27, 2020 12:42 pm

This is nonsense
It’s not water, it’s the cheese sweating.

Robert of Texas
October 27, 2020 2:02 pm


I was expecting some more interesting then “we found more water”. Yeah, yeah…we can mine it to reach other planets. We can also be sending more advanced robots that do not NEED this water to reach other planets.

People completely fail to understand how fast AI is evolving. I remember back around 1970 a “checkers” program was considered state-of-the-art. Now we have AI that can perform complex medical analysis and even some surgery. Just think where this will be in another 50 years.

Sending people into outer space is both costly and dangerous. We will eventually have better technology that reduces both the cost and the risk, but until then we should be sending robots into the hostile environment of space.

We should be focusing on reducing costs to get materials into an Earth orbit so that we can start building a real space station complete with artificial gravity (centrifugal force). That is a good first step on getting people into space in a practical and useful way. If you can build using larger masses, you can make planetary ships more safe.

Gordon A. Dressler
Reply to  Robert of Texas
October 27, 2020 5:36 pm


Why do we go hiking when we could instead fly drones, assisted by AI, along and/or above the hiking path?

Why do people climb mountains when we have numerous photos from previous climbers reaching the summits, including the tallest, Mt. Everest?

Why do astronauts and even paying citizens put their lives at significant risk and travel to ISS, when it’s previously been done by tens of others before them?

Why do some people build very expensive, deep diving vessels (aka bathyspheres, bathyscaphes) to travels miles below the ocean’s surface, when such could much more easily be done—and at much less cost—by robot submersibles?

For that matter, why did the US bother to send a dozen astronauts to the surface of the Moon when many robotic missions had landed there previously?

So many questions . . . so few answers.

Michael S. Kelly
October 27, 2020 9:52 pm

What’s really remarkable about the spacecraft is its use of Long Range Navigation (LORAN) technology, supplied by ESA. Without the pride and passion in this technology by the Italian participants in ESA, SOFIA LORAN would never have gotten off the ground…

Gordon A. Dressler
October 28, 2020 7:21 am

Michael S. Kelly posted; “What’s really remarkable about the spacecraft . . .”

Sorry, Michael, but SOFIA is not spacecraft.

“SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP aircraft modified to carry a 2.7-meter (106-inch) reflecting telescope (with an effective diameter of 2.5 meters or 100 inches). Flying into the stratosphere at 38,000-45,000 feet . . .” (source: ).

And LORAN dropped out of widespread about ten years ago, replaced by GPS technology that unlike LORAN offers extremely accurate geographic positioning and is available worldwide, and at much lower cost per receiver and without needing a large receiving antenna.

“In November 2009, the United States Coast Guard announced that Loran-C was not needed by the U.S. for maritime navigation. This decision left the fate of LORAN and eLORAN in the United States to the Secretary of the Department of Homeland Security. Per a subsequent announcement, the US Coast Guard, in accordance with the DHS Appropriations Act, terminated the transmission of all U.S. Loran-C signals on 8 February 2010. On 1 August 2010 the U.S. transmission of the Russian American signal was terminated, and on 3 August 2010 all Canadian signals were shut down by the USCG and the CCG.” (source: )

Michael S. Kelly
Reply to  Gordon A. Dressler
October 28, 2020 6:54 pm

I guess when I try to make a lame pun, I should at least do my homework. And to think, I knew perfectly well what SOFIA was back in the day… But now that I’m elderly, a lot is getting forgotten.

Verified by MonsterInsights