Lunar carbon dioxide cold traps discovered could be used to sustain robot or human presence on the moon.
After decades of uncertainty, researchers in Washington have confirmed the existence of lunar carbon dioxide cold traps that could potentially contain solid carbon dioxide. The discovery will likely have a major influence in shaping future lunar missions and could impact the feasibility of a sustained robot or human existence on the moon.
In the permanently shadowed regions in the poles of our moon, temperatures dip below those in the coldest areas of Pluto, allowing for carbon dioxide cold traps to occur. In these cold traps, carbon dioxide molecules can freeze and remain in solid form even during peak temperatures in the lunar summer.
Use of possible solid lunar carbon dioxide
This solid carbon dioxide could be utilised by future human or robot explorers to produce fuel or materials for longer lunar stays. The carbon dioxide and other potential volatile organics could also assist scientists to better understand the origin of water and other elements on the moon. Although cold traps have been predicted by planetary scientists for years, this new study is the first to decisively establish and map the presence of carbon dioxide cold traps. To locate the coldest spots on the moon’s surface, researchers analysed 11 years of temperature data from the Diviner Lunar Radiometer Experiment, an instrument flying aboard NASA’s Lunar Reconnaissance Orbiter.
According to this new research, published in the AGU journal Geophysical Research Letters, which publishes reports with immediate implications spanning all Earth and space sciences, it shows that these cold traps include several pockets concentrated around the lunar southern pole. The total area of these carbon dioxide traps totals 204 square kilometres, with the largest area in the Amundsen Crater hosting 82 square kilometres of traps. In these areas, temperatures continually remain below 60 degrees Kelvin (about minus 352 degrees Fahrenheit).
According to the researchers, the existence of carbon dioxide cold traps does not however promise the existence of solid carbon dioxide on the moon, but this verification does make it extremely likely that future missions could find carbon dioxide ice there.
“I think when I started this, the question was, ‘Can we confidently say there are carbon dioxide cold traps on the moon or not?’” said Norbert Schörghofer, a planetary scientist at the Planetary Science Institute and lead author on the study. “My surprise was that they’re actually, definitely there. It could have been that we can’t establish their existence, [they might have been] one pixel on a map. So, I think the surprise was that we really found contiguous regions which are cold enough, beyond doubt.”
Future lunar exploration
The existence of carbon dioxide traps on the moon will likely have implications for the planning of future lunar exploration and international policy regarding this resource. If there is indeed solid carbon dioxide in these cold traps, it could potentially be used in a variety of ways. Future space explorers could utilise the resource in the production of steel as well as rocket fuel and biomaterials, which would be essential for both sustained robot and human presence on the moon.
Scientists could also study lunar carbon dioxide to understand how organic compounds form and what kind of molecules can be naturally produced in these harsh environments. According to Paul Hayne, a planetary scientist at the University of Colorado, the carbon dioxide cold traps could also be used to help scientists answer long-standing questions about the origins of water and other volatiles in the Earth-moon system. Carbon dioxide could be a tracer for the sources of water and other volatiles on the lunar surface, helping scientists to understand how they arrived on the moon and on Earth.
“These should be high-priority sites to target for future landed missions,” Hayne said. “This sort of pinpoints where you might go on the lunar surface to answer some of these big questions about volatiles on the moon and their delivery from elsewhere in the solar system.”
