Dry ice on Mars may help colonize red planet, research says
Since man wants to start colonizing the place within the next few decades, we need all the help we can get. This could also have profound implications on planning. For now, we’re only considering one-way trips, owing to huge energy demands. This could change.
The gist of the new energy theory proposed by a team of researchers from Northumbria, Edinburgh and Newcastle universities lies in carbon dioxide. Scientists say the principle is no different to what happens when you observe the effect of a drop of water on a scalding-hot stove. The energy generated by that process, which agitates the drop of water, is similar to the pioneering new approach, outlined in the journal Nature Communications
Scientists call the principle at the heart of this process the Leidenfrost effect. This happens when a liquid comes into near contact with a much hotter surface. And it fits perfectly with the example of carbon dioxide – or dry ice.
In the case of carbon dioxide, blocks of the material are able to levitate above a hot surface because of protection given by the layer of evaporated gas. Researchers propose harnessing the power of that gas to power engines – the first time anyone has proposed to use the Leidenfrost effect to generate energy.
“By placing water droplets and small blocks of dry ice on top of hot, turbine-like surfaces, we have used the Leidenfrost effect to create rotational motion. The turbines channel the released vapor, whose flow in turn drives the levitating surface above to rotate,” says Dr. Rodrigo Ledesma-Aguilar, co-author on the research in a related article.
If scientists manage to harvest this energy, there is no reason why trips to Mars should be one-way. In 2013, science discovered there were massive deposits of dry ice on Mars.
The gullies observed on Mars were a topic of debate, as scientists searched for evidence of the water that once created them. But recent studies are overwhelmingly in favor of carbon dioxide.
The experts are not quite sure how exactly frozen carbon dioxide can cause gullies to form. This phenomenon isn’t encountered naturally on Earth, so there was nothing to compare the processes on Mars with. One possible mechanism is that soil sublimates frozen carbon dioxide, which allows it to flow. Another is the buildup of frozen gas, which causes steep slopes to slide.
And according to Rodrigo Ledesma-Aguilar’s in the university’s press release:“Carbon dioxide plays a similar role on Mars as water does on Earth. It is a widely available resource, which undergoes cyclic phase changes under the natural Martian temperature variations.”
“Perhaps future power stations on Mars will exploit such a resource to harvest energy as dry-ice blocks evaporate, or to channel the chemical energy extracted from other carbon-based sources, such as methane gas,” he also said, adding that “one thing is certain: our future on other planets depends on our ability to adapt our knowledge to the constraints imposed by strange worlds, and to devise creative ways to exploit natural resources that do not naturally occur here on Earth.”
Harvesting the results, according to the researchers, will be humanity’s biggest challenge in the 21st century.
An engine based on the Leidenfrost effect is different to the steam-based ones we’re used to here on Earth. “The high-pressure vapor layer creates freely rotating rotors whose energy is converted into power without the need of a bearing, thus conferring the new engine with low-friction properties,” says Dr Gary Well, another co-author.
“This is the starting point of an exciting avenue of research in smart materials engineering. In the future, Leidenfrost-based devices could find applications in wide ranging fields, spanning from frictionless transport to outer space exploration,” explains Professor Glen McHale, executive dean for Engineering and Environment at the university.
NASA currently has two robotic rovers operating on Mars, and three orbiting probes. The latest probe arrived in the Martian orbit in September 2014, on a mission to study the planet’s upper atmosphere. The agency is not planning any manned exploration missions until the 2030s at the earliest.