An underground river of molten rock may not sound like it could ever be somewhere hospitable. However, it is possible that the remnants of a lava river like this could help provide shelter for human habitations on the Moon in the future. I am researching lava tubes underneath the surface of the Moon, with the goal of being able to locate them from the surface. Lava tubes are long underground caves that are formed from lava flows, when the surface of the flow cools and crusts over. If this solid crust becomes thick enough, it can become a roof over the lava flow that can support its own weight. When the source of the lava flow stops, the molten rock inside the tube flows out and leaves a hollow underground cave, like a straw.
Image 1: Lava flow in Hawaii through a lava channel. When a flow like this roofs over, it can form a lava tube. (Image source: Volcanic Features of Hawaii and Other Worlds, USRA (https://www.lpi.usra.edu/publications/slidesets/hawaii/slidepages/slide_09.html))
Lava tubes are well documented on Earth, and some have become popular destinations for tourists or spelunkers. Nahuku, a tunnel in Hawaii which visitors can walk through, is one example. These tubes can be several meters wide and stretch for kilometers. On the Moon, lava tubes can potentially be much larger, up to kilometers in width; due to the lower gravity on the Moon, larger tubes can exist without collapsing in on themselves. We have not explored inside a lava tube on the Moon, but have found evidence that they exist. We have observed lunar tube skylights, or places where a part of the tube ceiling has fallen in, exposing the tunnel underneath.
Image 2: The interior of Nahuku, a lava tube open to visitors in Hawaii, with people for scale. (Image source: An Enlightening New Experience in Thurston Lava Tube, Hawai'i Volcanoes, National Park Service (https://www.nps.gov/havo/learn/news/20180202_nakuku_lighting.htm))
We are interested in finding lava tubes on the Moon because they could be extremely useful locations for a potential Moon base. The surface of the Moon is bombarded with radiation and tiny meteorites, which could be harmful to astronauts and any buildings on the surface. These are not an issue on Earth because of the thick atmosphere, which protects from meteorites, and the magnetic field, which blocks radiation. The Moon, however, lacks a magnetic field or atmosphere. If a Moon base was built inside a lava tube, the thick ceiling of rock would protect against these hazards like the roof of a house keeps out rain and harsh sunlight, without extra shielding being required.
Image 3: The location of the Marius Hills Pit, a hole on the surface of the moon thought to be a skylight into a lava tube. The pit is on the path of a sinuous rille, a channel on the lunar surface associated with lava flows. (Image Source: Technology Enabling Exploration of Skylights, Lava Tubes, and Caves, NASA Innovative Advanced Concepts Phase I, NASA (https://www.nasa.gov/pdf/718393main_Whittaker_2011_PhI_Cave_Exploration.pdf))
Image 4: Images of the Marius Hills Pit, taken by the Lunar Reconnaissance Orbiter. (Image Source: Confirmation of Sublunarean Voids and Thin Layering in Mare Deposits, Planetary and Space Science (https://www.sciencedirect.com/science/article/pii/S0032063312001195?via%3Dihub))
Image 3: The location of the Marius Hills Pit, a hole on the surface of the moon thought to be a skylight into a lava tube. The pit is on the path of a sinuous rille, a channel on the lunar surface associated with lava flows. (Image Source: Technology Enabling Exploration of Skylights, Lava Tubes, and Caves, NASA Innovative Advanced Concepts Phase I, NASA (https://www.nasa.gov/pdf/718393main_Whittaker_2011_PhI_Cave_Exploration.pdf))
Image 4: Images of the Marius Hills Pit, taken by the Lunar Reconnaissance Orbiter. (Image Source: Confirmation of Sublunarean Voids and Thin Layering in Mare Deposits, Planetary and Space Science (https://www.sciencedirect.com/science/article/pii/S0032063312001195?via%3Dihub))
I am modeling lava tubes to find how the lunar surface above them would be deformed by their presence, in order to help locate them on the Moon. I am currently using a simplified model of a lava tube’s shape, but I intend to later use a 3D scan of the inside of a real one on Earth instead, for more realistic results.
This is a great start on the blog with nice illustrations, but I am left wondering about the depth of lunar tubes and their length. Is there an image from the moon of the lunar skylights? For the generalized blog, the last sentence could be deleted.
ReplyDeleteYou give really good context as to why these objects are important to the common person. I think you may need to add an image of how lava tubes look like on the Moon. I'm thinking of a surface image of the moon.
ReplyDeleteThis is a really good blog! Maybe add a scale bar to Image 2 to make it visually apparent how large these tubes are. I think you gave a good description of the scale of the tubes but it might be helpful to have more visuals, or even see the model you're working on.
ReplyDeleteGreat flow and setting up the background information before describing how your research relates! I would make the captions on the figures smaller text because it gets a little visually confusing. Adding a scale (either numerically or with a little cartoon person) would help a lot.
ReplyDeleteThis is a really well written blog--your opening sentence is really compelling and the whole piece is cohesive. It would be helpful to have an example image of a lunar lava tube.
ReplyDeleteI like your analogy in which you compared a lava tube to a straw. That helped me understand and picture a lava tube. Are there any photographs of the partially-collapsed lava tube from the Moon? If so, that would be helpful to include in your blog. You did a good job explaining why a lunar tube would make an effective Moon base for astronauts.
ReplyDeleteYour analogies are simple and convey your message easily. I also like that your give an explanation of why we care about lava tubes and how they could be useful to us.
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