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39 votes
Accepted

Why do the boot prints on the moon appear bright in some photographs or film?

If you take a good look at contrast between the boot print and the unaffected/untouched dust on the lunar surface the unaffected/untouched dust is loose, undulating and has a matt (or matte, in some ...
Fred's user avatar
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26 votes

Rock arches on the moon?

There's a saying, "ask 4 geologists about a geological feature and you'll get 5 or 6 answers, maybe more". My interpretation of what you have highlighted is not a rock arch - an arched rock ...
Fred's user avatar
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24 votes

Is this white stuff seen by the Mars Phoenix Lander water or carbon dioxide ice?

It turns out there is a paper that discusses this exact ice patch: it's water ice, and they're referring to the white section at the top. (The small granules in the lower left may also be water ice, ...
Andrew is gone's user avatar
22 votes

Rock arches on the moon?

If it helps, following the citation trail leads to the back side of the same rock formation being visible on three other photographs on the same reel of film: https://history.nasa.gov/alsj/a16/AS16-...
SE - stop firing the good guys's user avatar
17 votes
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How much total lunar mass remains viable for analysis here on Earth?

A large amount of Moon samples has not been studied at all yet. Out of 9 sealed containers brought back to Earth in the Apollo program, 3 containers have never been opened. In early 2018, a group of ...
Hobbes's user avatar
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16 votes
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Martian dust getting into habitats

One proposed solution to contamination of a habitat by extra-vehicular activity is a Suitport which eliminates the need to bring the suits inside. The crewmember enters and exits the suit through a ...
Organic Marble's user avatar
15 votes
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What did walking on lunar regolith feel like?

According to Apollo 11 Lunar Surface Journal, Armstrong made his first description of the regolith as soon as he stepped out from the ladder and pronounced his famous "giant leap" phrase: ...
Sergiy Lenzion's user avatar
12 votes
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Can you really melt lunar regolith with microwaves?

Yes, really, and there's a NASA study that describes this method. The microwaves couple strongly with the Fe0 to such a degree that a sample of Apollo soil placed in an ordinary 2.45 MHz kitchen ...
Hobbes's user avatar
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11 votes
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How radioactive is surface regolith on the Moon?

tl;dr: This is not meant to be a at all a complete answer, but it's a start, and I think it gives a flavor of what will come; that in general the stuff is not very radioactive as (at)Gregg has already ...
uhoh's user avatar
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11 votes

Which scientific articles together give proof of all the chemical elements found on Mars?

From Mars Fact Sheet: hydrogen (H), carbon (C), nitrogen (N), oxygen (O), argon (Ar), neon (Ne), krypton (Kr), xenon (Xe). From Inorganic analysis of martian surface samples at the viking landing ...
Cornelis's user avatar
  • 7,535
10 votes

Why do the boot prints on the moon appear bright in some photographs or film?

Reflection Yes, as Fred points out, the boot prints act like crude mirrors. If you shine a flashlight at a mirror in a random direction, and place yourself at another random direction, the mirror will ...
Lawnmower Man's user avatar
8 votes

Why do the boot prints on the moon appear bright in some photographs or film?

Answer: Levitating Moon Dust and a walking capacitor. Previously submitted answers explain the brightness of footprints as specular (mirror-like) reflection, This begs the question of how a bootprint ...
Woody's user avatar
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7 votes
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Are rocks on Mars or the Moon the same as rocks on Earth?

Since rock is classified by formation processes, each type of rock would be about the same no matter what planet you found it on. (https://en.wikipedia.org/wiki/Metamorphic_facies) But you're right ...
HK JR's user avatar
  • 354
7 votes
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How thick does lunar regolith ever get? Has the thickness been measured and mapped by satellite?

First, we have to define 'regolith'. NASA uses the term for all unconsolidated debris, including large boulders: The lunar surface is covered by a layer of unconsolidated debris called the lunar ...
Hobbes's user avatar
  • 128k
7 votes
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What does lunar dust smell like?

All 12 of the astronauts who walked on the moon reported that the dust smelled like gunpowder. For example, during Apollo 16, Charlie Duke reported 150:09:18 Duke: Houston, the lunar dust smells ...
DrSheldon's user avatar
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7 votes

Can Martian regolith be easily melted with microwaves?

Answer: Not really. Martian regolith may be heated with microwaves. Considering this “easy” is a stretch. The two most common components of regolith are certainly not “easily” heated with microwaves. ...
Woody's user avatar
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6 votes

Is this white stuff seen by the Mars Phoenix Lander water or carbon dioxide ice?

tl;dr: The slow sublimation rate over 4 days rules out CO2 as the primary component (which would have sublimated much more quickly when exposed to the warm-ish atmosphere and sunlight), and careful ...
uhoh's user avatar
  • 149k
6 votes
Accepted

Perseverance's First Borehole looks like its particles of sand stuck together by something; composition of this material and source of adhesion?

Looking at an elevated perspective view of the drilling site the hole was drilled in apparently competent rock, not sand. It's why the walls of the hole are firm and intact. NASA personnel named the ...
Fred's user avatar
  • 13.1k
6 votes

DIY Lunar regolith simulant

The best bet is to get volcanic sand, which tends to have the rougher texture that is common on the Moon. Specifically, the base component to most NASA regolith stimulants is basaltic ash with a high ...
PearsonArtPhoto's user avatar
  • 121k
5 votes

How strong is the electric charge capacity of Martian dust storms?

As a Mars dust devil guy, I can say that the ubiquitous dust is NOT generally considered sharp-edged. Almost all of it is one of several clay minerals. Due to the absence of open water and given that ...
DrDirt's user avatar
  • 131
5 votes

DIY Lunar regolith simulant

During the development of Lunokhod, an Armenian volcanic pumice (gray color) was used as a cover for the test track. Lunadrom for training the crew of the Lunokhod was covered with Crimean shell rock (...
A. Rumlin's user avatar
  • 7,863
4 votes

Has any rover dragged a magnet across any solar system body to see what gets picked up or made magnetic measurements of specific rocks or particles?

Not a rover, but Surveyor 7 had magnets on its sampling arm. This spacecraft was similar in design to the previous Surveyors, but it carried more scientific equipment including a television camera ...
Organic Marble's user avatar
4 votes

Martian dust getting into habitats

Research into removing lunar dust from spacesuits and other equipment using electron beams may have a similar application on Mars. The success of the electron cleaning was dependent on the thickness ...
Fred's user avatar
  • 13.1k
4 votes
Accepted

What was the radius of Insight's disruption of Martian regolith?

This paper1 states that there is a ...quasi-circular disturbed zone of 15-21 m radius (~990 m2) around InSight. Based on HiRISE imagery and views from InSight cameras. 1SURFACE ...
Organic Marble's user avatar
4 votes

How much soil can be supported by an inflatable habitat on Mars?

You can get a ballpark figure by assuming the roof of the habitat is flat, supported entirely be air pressure and doesn't weigh much in and of itself. Your diagram suggests a full Earth atmosphere ...
Steve Linton's user avatar
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4 votes
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Why does NASA use Nitrogen storage for lunar regolith?

There's some explanation in Judy Allton's 1994 "Archivist's Notes #3: Lunar Samples Presently Curated Under Helium". First, a definition: An SESC is the vacuum container used to transport from the ...
Bob Jacobsen's user avatar
  • 12.7k
4 votes

Rock arches on the moon?

There are two rocks one big one in the back ground and a smaller one slightly closer. Something is casting a very deep shadow across to bottom of both. The deep shadow makes it impossible to see the ...
Slarty's user avatar
  • 9,802
3 votes

Why is there no exosphere demonstrating moon dust and particles in the Apollo footage?

This study explores the mechanisms behind dust levitation. Itputs the levitation altitude at 10 cm. The study also shows why the Surveyor landers recorded a glow that can be attributed to levitating ...
Hobbes's user avatar
  • 128k
3 votes

DIY Lunar regolith simulant

Slag. The moon is differentiated. Effectively, lunar regolith is ore that has been “de-ored”; all valuables have been pulled out (depleted), both by sinking to the core (siderophiles) and by degassing ...
caInstrument's user avatar
3 votes

What did walking on lunar regolith feel like?

Since the bulk of regolith has a density of 1.5 g/cm3, and "talc, broken" has a density of 1.746 g/cm³ I wonder if comparing the two has validity. Density is not the only factor in how a substance ...
Hobbes's user avatar
  • 128k

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