Author Topic: Lunar Pits have stable temperatures  (Read 1995 times)

Offline redliox

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Lunar Pits have stable temperatures
« on: 07/26/2022 09:59 pm »

Pits were first discovered on the Moon in 2009, and since then, scientists have wondered if they led to caves that could be explored or used as shelters. The pits or caves would also offer some protection from cosmic rays, solar radiation and micrometeorites.

“About 16 of the more than 200 pits are probably collapsed lava tubes,” said Tyler Horvath, a doctoral student in planetary science at the University of California, Los Angeles, who led the new research, recently published in the journal Geophysical Research Letters.

“Lunar pits are a fascinating feature on the lunar surface,” said LRO Project Scientist Noah Petro of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Knowing that they create a stable thermal environment helps us paint a picture of these unique lunar features and the prospect of one day exploring them.”

Lava tubes, also found on Earth, form when molten lava flows beneath a field of cooled lava or a crust forms over a river of lava, leaving a long, hollow tunnel. If the ceiling of a solidified lava tube collapses, it opens a pit that can lead into the rest of the cave-like tube.

Two of the most prominent pits have visible overhangs that clearly lead to caves or voids, and there is strong evidence that another’s overhang may also lead to a large cave.

“Humans evolved living in caves, and to caves we might return when we live on the Moon,” said David Paige, a co-author of the paper who leads the Diviner Lunar Radiometer Experiment aboard LRO that made the temperature measurements used in the study.

Horvath processed data from Diviner – a thermal camera – to find out if the temperature within the pits diverged from those on the surface.

View of the Mare Tranquillitatis pit crater
This is a spectacular high-Sun view of the Mare Tranquillitatis pit crater revealing boulders on an otherwise smooth floor. This image from LRO's Narrow Angle Camera is 400 meters (1,312 feet) wide, north is up.
Credits: NASA/Goddard/Arizona State University
Focusing on a roughly cylindrical 328-foot (100-meter)–deep depression about the length and width of a football field in an area of the Moon known as the Mare Tranquillitatis, Horvath and his colleagues used computer modeling to analyze the thermal properties of the rock and lunar dust and to chart the pit’s temperatures over time.

The results revealed that temperatures within the permanently shadowed reaches of the pit fluctuate only slightly throughout the lunar day, remaining at around 63 F or 17 C. If a cave extends from the bottom of the pit, as images taken by LRO’s Lunar Reconnaissance Orbiter Camera suggest, it too would have this relatively comfortable temperature.

The team, which included UCLA professor of planetary science David Paige and Paul Hayne of the University of Colorado Boulder, believes the shadowing overhang is responsible for the steady temperature, limiting how hot things gets during the day and preventing heat from radiating away at night.

A day on the Moon lasts about 15 Earth days, during which the surface is constantly bombarded by sunlight and is frequently hot enough to boil water. Brutally cold nights also last about 15 Earth days.

The research was funded by NASA’s Lunar Reconnaissance Orbiter project, Extended Mission 4. LRO is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, for the Science Mission Directorate at NASA Headquarters in Washington. Launched on June 18, 2009, LRO has collected a treasure trove of data with its seven powerful instruments, making an invaluable contribution to our knowledge about the Moon. Diviner was built and developed by the University of California, Los Angeles, and NASA's Jet Propulsion Laboratory in Pasadena, California.

NASA is returning to the Moon with commercial and international partners to expand human presence in space and bring back new knowledge and opportunities.

Bill Steigerwald

I've tended to favor lunar caves over the lunar poles, so this news catches my eye.  I'd be willing to bet the deeper parts of these caves could be cool enough for ice pockets.
"Let the trails lead where they may, I will follow."

Offline Dalhousie

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Re: Lunar Pits have stable temperatures
« Reply #1 on: 07/31/2022 02:29 am »
This is true for caves everywhere.
Apologies in advance for any lack of civility - it's unintended

Offline Rondaz

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Re: Lunar Pits have stable temperatures
« Reply #2 on: 08/11/2022 05:24 pm »
In new NASA-funded research, data from the Lunar Reconnaissance Orbiter was used to investigate the temperatures of lunar surface pits & caves.

Results showed temperatures in the pits that could be suitable for future surface bases on the Moon.

Offline Phil Stooke

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Re: Lunar Pits have stable temperatures
« Reply #3 on: 08/12/2022 07:16 am »
It looks like the study only dealt with one pit, that in Tranquillitatis*, which is close to the equator (8.3 degrees north) and so quite well illuminated at noon.  Other pits at higher latitudes will have less direct heating and presumably lower temperatures (probably still quite comfortable in Marius Hills and Ingenii, the other two well-known pits).  At LPSC Pascal Lee described a pit in impact melt at 79 degrees south which would be much cooler.  So don't automatically apply this reported temperature to all pits.

*EDIT:  oops, sorry, Ingenii is also in the study.  But the basic point that pits at higher latitudes will be cooler is still correct (I think).
« Last Edit: 08/12/2022 09:29 pm by Phil Stooke »

Offline jebbo

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Re: Lunar Pits have stable temperatures
« Reply #4 on: 08/12/2022 08:22 am »
I particularly like the one NW of Gruithuisen Crater which has a kilomtres-long uncollapsed section:

--- Tony

Tags: Moon cave pits LRO 

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