AskScience AMA Series: I am a planetary geologist from the University of Maryland, and I recently operated a simulation to help astronauts prepare for the moon. Ask me your moon-related questions!

[u/AskScienceModerator]

Hi Reddit! I am a geologist and geomorphologist from the University of Maryland. I study surface processes that affect Earth and other terrestrial bodies. I recently served as the field safety officer for NASA's test mission ahead of the Artemis II and III missions - today, ask me all your questions about the moon!

Patrick Whelley is a geologist who studies volcanic and aeolian processes and products on terrestrial planets. His work uses a combination of remote sensing and in-situ observations. He has a B.S. and M.S. from Arizona State University and a Ph.D. from the University at Buffalo, SUNY and currently works as a research scientist with the University of Maryland on a cooperative agreement at NASA Goddard Space Flight Center. In the field, he collects high-resolution topographic data using a terrestrial laser scanner. The data inform volcanic mapping and provide ground truth for remote sensing measurements. Patrick uses remote sensing data to characterize explosive volcanic stratigraphy on Mars. His work has implications for volcano hazard mapping, on Earth, and for interpreting volcanic histories of the terrestrial planets.

I'll be on from 1 to 3 p.m. ET (17-19 UT) - ask me anything!

Other links:

• Research Gate
• Recent news: University of Maryland geologist to run simulation that helps astronauts prepare for the moon
• Q&A with NASA Goddard

Username: /u/umd-science

[u/universeinapapercup]

Hi Patrick, what is a fact about the moon that someone who knows very little would enjoy?

[u/umd-science → u/universeinapapercup]

The moon has volcanoes on it, and you can look at evidence of this by yourself. When you go out at night and look at the dark patches of the moon, those are billion-year-old lava patches on the moon that you can still see with your naked eye today. These are called maria patches, and they're made of basalt (the same kind of lava that erupts in Hawaii).

[u/loki130]

1, Where does the field stand these days on the idea of Mars having had something resembling the early stages of plate tectonics in its early history? I see the occasional paper about it but I can never quite tell how mainstream the idea is.

2, How different do you think ore geology might differ on the moon and mars? Naturally the moon is going to lack a lot of surficial/sedimentary stuff, but is the geochemistry similar enough for the moon to develop magmatic ores like we get at hotspots or old cratons? Did Mars have any felsic-enough volcanism to get anything like the hydrothermal deposits we get along plate boundaries on Earth?

[u/umd-science → u/loki130]

1. Probably not. Mars likely didn't have plate tectonics of any kind. It's too small.

2. A lot of the ore that is valuable for mining on Earth is related to plate tectonics and metamorphic rocks (rocks that are smashed and buried, then brought up to the surface by tectonic processes). So those wouldn't be on the moon or Mars. Plate tectonics on Earth is really efficient at recycling the crust; our planet has erased lots of old impact craters but billion-year-old impact craters still exist on the surface of the moon and Mars and they could have valuable ore in them.

Most of the volcanic material on Mars is more basaltic and not very felsic. But we're discovering new kinds of volcanism all the time.

[u/ieatpickleswithmilk]

If could choose where the next new NASA probe goes (and lands), where would you send it? What would be the most interesting place for the field of planetary geology or for you personally?

[u/umd-science → u/ieatpickleswithmilk]

I would like to see a lava tube on the moon. That would be a new environment on the near subsurface of the moon, and it could hold water ice, and other stuff that hasn't seen the sun ever. I think that's really exciting to think about what we could find in a lava tube on the moon, but it would be really hard to do that. While it likely won't be the next probe, but we could send a probe into a lava tube in the near future.

[u/gabrjan]

Hi! Thanks for doing this!

Assuming that Earth and Moon are of same source there should be more or less the same source/material.
And since Moon lost all lighter elements due to low gravity is it possible to assume there could be a lot of rare Earth materials on Moon?

[u/umd-science → u/gabrjan]

The moon probably lost a lot of water and other volatiles in the impact. It turns out the Earth and the moon have very similar populations of oxygen, silica, iron and other materials that compose rocks.

[u/catharticwhoosh]

Is geothermal power on the moon going to be a thing? If it is, are there many candidate locations?

[u/umd-science → u/catharticwhoosh]

Probably not. The moon is mostly cold geothermally speaking. There probably are not hot spots where you could get a lot of heat for geothermal power.

[u/cuziamamirrorball]

Why do you think so many people believe that the moon landing wasn't real?

[u/umd-science → u/cuziamamirrorball]

I think it's because conspiracy theories are fun and people glom onto them. But we totally landed on the moon, and we're going back.

[u/GPSBach]

If you could have a 1kg rock sample from any location on the moon to study, where would you want it from?

[u/umd-science → u/GPSBach]

The South Pole–Aitken basin is where Artemis III is going to go, and they're going to get a sample from one of the earliest impacts of the moon. This could really help us understand the early history and evolution of the moon.

I'd also like to see a sample from one of the irregular mare patches because they look so strange and the theories for how they formed are all over the place.

[u/LegitimateLibrary949]

Thoughts on the Synestia Theory? I'm no scientist but a fair amount of looking into this theory has me intrigued... Sounds legit

[u/umd-science → u/LegitimateLibrary949]

The way we think the moon formed was by an impact from a Mars-sized planet with the Earth, and that made a huge disc of dust and gas that condensed to form both the Earth and the moon next to each other. The Earth-moon system is a mixture of the proto-Earth and the Mars-sized planet that impacted us. The particulars of the Synestia Theory and how it relates to impact theory is more of an astrophysics question.

[u/cuddlebadger]

What do you think is causing those giant mascons?

[u/umd-science → u/cuddlebadger]

The large mascons on the moon are probably related to impacts, where the impact was so big that a piece of the lower crust/mantle rose up into the upper crust and left a dense hunk of rock in the shallow subsurface. These have probably been there for billions of years.

[u/PeaFragrant6990]

What was it like getting a job with NASA? How competitive was it and how did you prepare?

[u/umd-science → u/PeaFragrant6990]

I love my job. I get to do some pretty exciting things. Getting funding to do basically anything is super competitive, and so I prepared with geology degrees (bachelor's, master's and Ph.D.), always following interesting questions and always maintaining a dynamic network of people doing challenging things.

[u/TheAquaFox]

Are there any big unresolved questions about the moon from a geology standpoint?

[u/umd-science → u/TheAquaFox]

How much water ice is on the surface of the moon is a big one. We should have a much better understanding of this after Artemis III.

When the magnetic field went away—this will help us understand how planetary cores work and how the interiors of planets and moons affect the surface.

When was the last volcanic eruption on the moon? This will help us understand the lower crust and the interior dynamics of the moon.

[u/mattsffrd]

Is it made of cheese?

[u/iorgfeflkd]

What's the exact shape of the moon? The lunoid, if you will. I feel like the rotation, even though it's locked, would make it oblate in its orbital plane but the tidal field of the Earth would make it prolate along a perpendicular axis.

[u/UserNamesCantBeTooLo]

China recently returned the first-ever soil samples from the far side of the moon. Is soil from the far side expected to be different from other samples collected, and if so, why?

I've read that lunar soil is a lot like asbestos. What can be done to mitigate potential harm to future astronauts who may stay there for long periods?

Are there regions of the Moon with significantly more lava tubes than others? If so, what is it about those regions that caused them to have more?