From Cave Man To Cave Martian: Living In Caves ...
He found that in many cases the levels of UV radiation inside the caves would be around 2 per cent of the levels on the surface. Those radiation levels are low enough to be relatively safe, but still high enough to sustain organisms that require light to produce energy via photosynthesis.
From Cave Man to Cave Martian: Living in Caves ...
The consequences of this are twofold: caves may be safe locations for human explorers to hide from the extreme conditions at the Martian surface, and they may also be some of the best places to search for signs of life on the Red Planet. No lander or rover has ever visited a cave on Mars, but doing so would be the best way to figure out whether they really are habitable, says Viúdez-Moreiras.
CTX images show the Martian surface in visible (red) wavelengths at a scale of 6 m/pixel, which is sufficient to identify sky-facing, shadowed cave entrance candidates as small as 25 m across. Many of the highest quality candidates identified in the CTX survey were subsequently targeted HiRISE, which observes at scales as fine as 0.25 m/pixel (about 1/500 of a single CTX pixel). This ultrafine resolution achieved by HiRISE is useful to determine which candidates (of those identified in CTX images) show evidence that subsurface cavities may extend beyond the observed line of sight (e.g., overhanging rims, surface skylights, etc.); this resolution also provides sufficient detail to characterize fine-scale surface features in and around the entrances such as aeolian bedforms, cliff-wall strata and dust/bedrock interfaces.
It's a good question, but it's not the right question -- yet. An international collaboration of scientists led by NAU researcher Jut Wynne has dozens of questions we need asked and answered. Once we figure out how to study caves on the Moon, Mars and other planetary bodies, then we can return to that question.
Wynne, an assistant research professor of cave ecology, is the lead author of two related studies, both published in a special collection of papers on planetary caves by the Journal of Geophysical Research Planets. The first, "Fundamental Science and Engineering Questions in Planetary Cave Research," was done by an interdisciplinary team of 31 scientists, engineers and astronauts who produced a list of 198 questions that they, working with another 82 space and cave scientists and engineers, narrowed down to the 53 most important. Harnessing the knowledge of a considerable swath of the space science community, this work is the first study designed to identify the research and engineering priorities to advance the study of planetary caves. The team hopes their work will inform what will ultimately be needed to support robotic and human missions to a planetary cave -- namely on the Moon and/or Mars.
The second, "Planetary Caves: A Solar System View of Products and Processes," was born from the first study. Wynne realized there had been no effort to catalog planetary caves across the solar system, which is another important piece of the big-picture puzzle. He assembled another team of planetary scientists to tackle that question.
"With the necessary financial investment and institutional support, the research and technological development required to achieve these necessary advancements over the next decade are attainable," Wynne said. "We now have what I hope will become two foundational papers that will help propel planetary cave research from an armchair contemplative exercise to robots probing planetary subsurfaces."
There are a lot of them. Scientists have identified at least 3,545 potential caves on 11 different moons and planets throughout the solar system, including the Moon, Mars and moons of Jupiter and Saturn. Cave formation processes have even been identified on comets and asteroids. If the surrounding environment allows for access into the subsurface, that presents an opportunity for scientific discovery that's never been available before.
The discoveries in these caves could be massive. Caves may one day allow scientists to "peer into the depths" of these rocky and icy bodies, which will provide insights into how they were formed (but also can provide further insights into how Earth was formed). They could also, of course, hold secrets of life.
"Caves on many planetary surfaces represent one of the best environments to search for evidence of extinct or perhaps extant lifeforms," Wynne said. "For example, as Martian caves are sheltered from deadly surface radiation and violent windstorms, they are more likely to exhibit a more constant temperature regime compared to the surface, and some may even contain water ice. This makes caves on Mars one of the most important exploration targets in the search for life."
"Radiation shielding will be essential for human exploration of the Moon and Mars," said Leroy Chiao, a retired astronaut, former commander of the International Space Station and co-author of the first paper. "One possible solution is to utilize caves for this purpose. The requirements for astronaut habitats, EVA suits and equipment should take cave exploration and development into consideration, for protection from both solar and galactic cosmic radiation."
Wynne, whose primary research is in terrestrial caves, said planetary cave research has long been a parallel research question to the earthly variety for nearly two decades. Caves support unique ecosystems that are sometimes quite divorced from the surface ecosystem in the same area. Who's to say a cave on the Moon or Mars would not be similar? So, many questions he's investigated about caves on Earth, he's wondered how it could apply on other planets.
He's not the only one making the connection. Wynne has done multiple research projects with NASA to help advance detection technologies, and his modeling of cave habitats does not much care if a cave is terrestrial or extraterrestrial. There are enough similarities in the cave environment to make reasonable predictions that will factor prominently into the selection of cave targets for exploration.
"Tellurian caves at depth are often characterized by complete darkness, a stable temperature approximating the average annual surface temperature, low to no air flow and a near-water-saturated atmosphere," he said. "The caves of other planetary bodies likely exhibit similar environmental conditions, but these will also be influenced by the surface conditions of the planetary body and the internal structure of the cave."
"Humans have been living in caves for hundreds of thousands of years. Then they built their own when none were available," he said. "As such, it is only natural to assume that caves will offer similar utility as humanity expands to other worlds. While planet-wide terraforming may be an end goal, the use of large, pre-existing structures such as caves and lava tubes may be a more practical way to bootstrap the technology to the maturity needed to tackle the surface of an entire planet."
While much of this research is forward-looking, there's also a need to consider what resources, research and support currently exist. Numerous robotic platforms and instrumentation suites are being tested, but the roadblock comes where it so often does -- the lack of funding. With sufficient support, a robotic exploration mission to a lunar or Martian cave could be possible in the next five to 10 years.
Several natural vertical fractures are also visible in the image, among them fractures caused by the way rocks weather on Mars; and the small cave or "door" seems to have formed where the vertical fractures intersect with the strata, he said.
"It's a very beautiful fractured outcrop, indeed," said geologist Angelo Pio Rossi of Jacobs University in Bremen, Germany. Rossi has created panoramas of the outcrop from successive photographs from the Curiosity rover, and he too thinks the door-shaped cave was produced by the visible fractures in the rock.
Hints of subsurface tunnels have been found in images ofMars before, but the new evidence is more suggestive, said Glen Cushing, aphysicist with the U.S. Geological Survey who discovered the possible caves.
"Caves can protect human explorers from a range ofdangerous conditions that exist on Mars' surface," Cushing said. "Ifcaves are not used for long-term human habitation, then explorers must eithertransport substantial shelters of their own or build them on site."
For these same reasons, caves are more likely to preserveany evidence of past life. "Caves are probably among the only places onMars where you can actually look and see if there's possible evidence" ofpast life, Cushing said.
I first came across the research at Bluefish Caves in the early 1990s. As a science journalist, I was working on a book on North American archaeology, and I was curious about what Cinq-Mars and his team had found. I called him up and near the end of the conversation, I inquired about the possibility of traveling to Bluefish Caves, which lay north of the Arctic Circle. A few weeks later, Cinq-Mars invited me along on some helicopter surveying planned for the summer and offered to show me the caves. I booked a ticket to Old Crow.
He will want to come to you and be more interested in you. But he will still need to take his time to pull away. And then... he will come back again. Because he loves you. Even when he detaches to visit his cave.
In the lava tube next to this one, other JPL researchers are testing an idea for a new communication method that could let a cave-exploring robot talk to its lander through many feet of rock. Others test a technique that could map caves from orbit.
LEMUR is designed to crawl into a cave opening without assistance, and the robot would have to navigate the unpredictable twists and turns of a lava tube, just as a human cave explorer would, perhaps at times even hanging by one or two paws in order to get around big obstacles.
Another way around the communication problem is to give the robot more autonomy, so it can make at least some decisions about how to move, where to go, and what to look at without needing instructions from Earth. Right now, such artificial intelligence software is in its infancy. But the engineers can at least develop ways for the robots to find their way around pitch-black caves. 041b061a72