Starship Asterisk*

http://www.lpi.usra.edu/publications/slidesets/hawaiivolcanoes/slidespages/slide_11.html wrote:
Marius Hills, Moon


<<Although most lunar volcanism produced the broad lava flows that infill the lunar maria, in a few places, such as the Marius Hills (14°N, 56°W), it is possible to find volcanic domes. In this scene we can see several lunar domes. Some of these domes are quite smooth and low, while others are more rugged and heavily cratered. Two large sinuous rilles similar to Hadley Rille can also be seen cross-cutting a mare ridge.>>

http://www.cnn.com/2010/TECH/space/01/01/moon.lava.hole/ wrote:
Moon hole might be suitable for colony
January 1, 2010 1:03 p.m. EST

Marius Hills Hole


(CNN) -- <<Building a home near a moon crater or a lunar sea may sound nice, but moon colonists might have a much better chance of survival if they just lived in a hole. That's the message sent by an international team of scientists who say they've discovered a protected lunar "lava tube" -- a deep, giant hole -- that might be well suited for a moon colony or a lunar base.

The vertical hole, in the volcanic Marius Hills region on the moon's near side, is 213 feet wide and is estimated to be more than 260 feet deep, according to findings published in Geophysical Research Letters, a journal of the American Geophysical Union. More important, the scientists say, the hole is protected from the moon's harsh temperatures and meteorite strikes by a thin sheet of lava. That makes the tube a good candidate for further exploration or possible inhabitation, the article says.

"Lunar lava tubes are a potentially important location for a future lunar base, whether for local exploration and development, or as an outpost to serve exploration beyond the Moon," writes the team, led by Junichi Haruyama, a senior researcher with the Japanese space agency JAXA. "Any intact lava tube could serve as a shelter from the severe environment of the lunar surface, with its meteorite impacts, high-energy UV radiation and energetic particles, and extreme diurnal temperature variations."

Lava tubes have previously been discovered on the moon, but the scientists say the new hole is notable because of its lava shield and because it does not appear to be prone to collapse. Lave tubes exist on Earth and also have been found on Mars. The cylinder-shaped caverns can be carved out by lava flows, volcanic eruptions, seismic activity or ground collapse resulting from meteoroid strikes.

The scientists used high-resolution images from a Japanese moon orbiter called SELENE to discover this lunar lava tube. The findings were published November 12, but they grabbed the attention of the public this week.>>

http://en.wikipedia.org/wiki/The_First_Men_in_the_Moon wrote:
<<The First Men in the Moon is a 1901 scientific romance novel by the British author H. G. Wells. The novel tells the story of a journey to the moon undertaken by the two protagonists, the impoverished businessman Mr Bedford and the brilliant but eccentric scientist Dr. Cavor.

At the Moon, the two men at first discover a desolate landscape, but as the sun rises, the thick atmosphere of the Moon, frozen out overnight, begins to melt and vaporize. They are captured by the insect-like Moon men (referred to as "Selenites"), who have formed a relatively advanced society underground. After some time in captivity, Bedford and Cavor manage to flee. Bedford finds his way back to the spaceship and returns to Earth while Cavor becomes injured and is unable to escape recapture by the Selenites.

Back in Britain, Bedford undertakes to publish the details of the story, including some additional material from Cavor received through one-way radio transmission from the Moon. Bedford learns of Cavor's meeting with the "Grand Lunar", who is the ultimate ruler of the Selenites and the Moon. At this meeting, Cavor inadvertently portrays humanity as predatory, delighting in war, and with little redeeming value. In response, the Grand Lunar decides to cut off all contact with the Earth. Cavor's transmissions end in mid-sentence...>>

http://news.discovery.com/space/moon-lunar-lava-skylight.html wrote:
Living in Lunar Lava Tubes
By Ian O'Neill | Tue Oct 27, 2009 12:28 PM ET

<<One of the key questions when we eventually return to the Moon will be: where are we going to live? Perhaps one solution has just presented itself in the form of a hole in the lunar surface, possibly leading to a hollow lava tube. This natural formation is known as a "skylight" and up until now little was known about where they are located and how many there are. A Japanese team headed by Junichi Haruyama has analyzed data from the JAXA Kaguya mission to find these holes in the ground, and after two years of searching, they've found one in the Marius Hills region of the Earth-facing side of the Moon. The skylight is approximately 60 meters wide and it provides a tantalizing glimpse into what could be a future target for manned lunar exploration.

Carolyn van der Bogert, a co-investigator from University of Münster in Germany,
has kindly taken the time to answer a few questions from Discovery News:

Ian O'Neill: How long have lunar missions been searching for lava tube "skylights"?[/color]

Carolyn van der Bogert: The possibility of using lava tubes as shelters was first proposed, to my knowledge, in 1985 by Fred Hörz in a NASA report about lunar bases. Besides outlining the advantages to using a natural shelter as a base, Hörz argues that there are probably a lot of lava tubes on the Moon, because they are thought to be related to sinuous rilles. Sinuous rilles are thought to form in two ways: (1) an open lava channel that thermally erodes into the lunar surface, or (2) subsurface lava tubes that eventually collapse. There were images of collapsed lava tubes that were discussed in the mid to late 1970's as evidence for volcanic activity and sinuous rille formation on the Moon.[/color]

Ian: The SELENE/Kaguya mission has discovered the first skylight. Will you and your JAXA colleagues be continuing to search for more skylights? How many more do you expect to find?

Carolyn: The search for this first skylight covered one of the most likely regions where they might be found: Marius Hills. A 500 square kilometer (200 square mile) area was searched, and this one skylight was found. This indicates that skylights exist, but are probably rare. However, we would be very surprised if there are not skylights in other similar volcanic provinces. We are certainly looking for more skylights.

Ian: What are your plans for the future of the Marius Hills observations? Will your results be used by space agencies investigating potential habitats for future space settlers?

Carolyn: The highest resolution images acquired by the Kaguya Terrain Camera were 6 meters/pixel, whereas the LROC-NAC images will have a resolution of 0.5 meters/pixel. It may also be possible to make some oblique observations as well. One of the requirements for the LROC mission is to supply NASA with data for evaluation of Constellation Program landing sites. Information, like the locations of potentially useful lava tubes, will be included in this information and used to select Constellation landing and outpost sites.

Ian: Is there any indication to suggest the Marius Hills skylight could access an underground network of tunnels?

Carolyn: It is hard to say whether the Marius Hills Hole might access an underground network of tunnels. It is a possibility, because we know that lava tubes on Earth can be many kilometers long. In the paper, using geometry, we calculated that the tube width might be on the order of 370 meters, but it could be anywhere from meters to kilometers long. Remote observations cannot answer this question for us -- it's like we're trying to see an entire room by looking through a keyhole. Ground-based exploration could answer this question. For example, Haruyama and Japanese colleagues, including Hideaki Miyamoto (also a co-author), have tested whether ground penetrating radar (GPR) might be useful in detecting intact sub-surface lava tubes. They tested their technique at Mt. Fuji, and were successful. It would certainly be interesting to do a GPR study in any region of the Moon where lava tubes might be present!

Ian: Personally, what would you expect the mission profile of a lunar mission would look like if we used natural shelter (such as lava tubes) to protect ourselves from radiation? Do you think this would be a cheaper alternative than building surface habitats?

Carolyn: Lava tubes would not only protect us from radiation, but also from meteoroid impacts and the extreme temperature changes over the lunar day. Near the equator, the lunar night is very cold (about -150 °C), and the lunar day, it is very hot (about 110 °C). A lava tube has a constant temperature, about -20 °C -- just like caves on the Earth have very even temperatures. It is important that the costs of accessing the geological shelter not exceed the costs of a surface shelter. There is a lot of discussion about whether it would be easy to access a lava tube from a skylight -- there would need to be some sort of elevator to carry people and materials to the floor.>>

Is this a window into the interior of the Moon, and an entrance to a potential future lunar habitat? The Lunar Reconnaissance Orbiter Camera has taken a closer look at what is thought to be a skylight into a lava tube in the Mare Ingenii (The Sea of Cleverness) region, one of the few lunar mare features on the far side of the Moon. This skylight is huge — about 130 meters (427 feet) in diameter — and is probably the result of a partially collapsed lava tube. But lunar geologists really weren't expecting to see this kind unusual feature in this region. Previously, a skylight, or open pit was found in the Marius Hills region in the Ocean of Storms on the near side which is filled with volcanic domes and rilles where a lava tube might form. However, those kinds of volcanic features are not found in Mare Ingenii. LRO will definitely be taking additional looks at this pit.

The Japanese SELENE/Kaguya spacecraft first discovered this irregularly-shaped hole, visible in the top image at LROC's 0.55 m/pixel resolution. The boulders and debris resting on the floor of the pit are partially illuminated (left side of the pit) and probably originated at the surface, falling through the pit opening during collapse.

This could be an important find for several reasons. Lava tubes are important in understanding how lava was transported on the early moon, but they could also provide a home to future human explorers. This one on the far side would be a great place to set up a base for future telescopes proposed for observations out into the Universe from the Moon's far side. The Moon's surface is a harsh place, the human body doesn't do well when exposed to the constant radiation present on the Moon's atmosphere-less environment. Long term human presence would work if astronauts could spend most of their time shielded underground. While excavating a hole large enough to fit an entire moon colony in it would be a huge engineering challenge, these lava tubes could provide ready-made locations for a well-shielded base.

Read our previous article about the pit in the Marius Hills.

Future lunar astronauts may want to brush up on their spelunking skills: the first lava tube has been discovered on the moon.

In a recent paper published in Geophysical Research Letters, Junichi Haruyama and colleagues report that they have discovered a mysterious hole in the lunar surface in high resolution images from the Kaguya spacecraft. The hole is 65 meters in diameter and is located in the volcanic Marius Hills region on the near side of the moon, right in the middle of a long sinuous rille. Sinuous rilles are thought to be formed by flowing lava, either on the surface or in enclosed lava tubes.

Of course, there are a lot of ways to form a hole in the surface of the moon. The most obvious is with an impact: the moon has literally been battered to pieces over the years by rocks from space. Couldn't this hole be a fresh impact crater? Nope. Haruyama's team observed the hole nine separate times, at various illumination angles, and even when the sun was almost directly overhead it looked mostly black, suggesting that it is very deep. They calculate a depth of around 88 meters, so the hole is deeper than it is wide. No impact crater is like that.

Another possibility is that the hole is due to some sort of volcanic eruption, but there is no sign of volcanic deposits like lava flows or ash emanating from the hole. The hole is isolated, so it isn't likely to be due to a fracture in the lunar crust either – you would expect such a fracture to form a chain of holes.

Haruyama's team concluded that the most likely explanation is that the hole that they discovered is a "skylight" – a location where the roof of a lava tube collapsed, either when the lava filling the tube flowed away, or later in the moon's history due to an impact, moonquake, or tidal forces from the Earth. If it is a lava tube, their calculations based on the multiple images of the hole show that the tube could be 370 meters across.

Lava tubes are important in understanding how lava was transported on the early moon, but they are not just a scientific curiosity: they may also provide valuable refuges for future human explorers. The surface of the moon is not protected from the harsh radiation of space by a magnetic field or a thick atmosphere, so a long term human presence would be most feasible if astronauts could spend most of their time shielded underground. Digging a hole large enough to fit an entire moon colony in it would be a huge engineering challenge, but lava tubes could provide ready-made locations for a well-shielded base, making future astronauts the most technologically advanced cave-dwellers in history.

Would you not be able build a dome like structure over the top of this hole and pump oxygen into it? effectively creating the solar systems biggest living room?

wonderboy wrote:This is the moon though rob. not mars. I'm pretty sure if they put their minds to it, they could build a dome which would withstand all the pressures as well as make sure that the hole would be air tight. after all, they have a space suit helmet, which would be the fraction of the thickness of a space dome on the moon, which can withstand the pressures of space.

wonderboy wrote:Quite scary to think that 4-5 inches seperates you from absolute certain death. It doesnt need to be a glass dome tho, it could be a big metal monstrosity of some sorts. It would be a start. Although something tells me there are just as many problems with metal, am i right???

rstevenson wrote:How thick are those new windows on the ISS?

ESA: Cupola wrote:Each window has three subsections: an inner scratch pane to protect the pressure panes from damage inside Cupola; two 25 mm-thick pressure panes to maintain cabin pressure (the outer pane is a back-up for the inner pane); and a debris pane on the outside to protect the pressure panes from space debris when the shutters are open.