Life on Mars: Dry ice could provide energy for future colonies on Mars

Since  NASA announced its plan to send an exploratory mission to Mars, the public interested in astronomy was very excited about the possibility of finally seeing the visit to the red planet carried out. The US Space Agency's current plans include sending humans to the planet in early 2030. In order to establish colonies in Mars, it would be necessary to build power generation engines. This would imply finding alternative energy sources and working with substances that can convert heat into useful energy.

Recently, research published in the journal Communications, shows a new way to do this using a substance easily found on our planet: the solid form of carbon dioxide (CO2), known as dry ice. To understand how the process works, it is necessary to resort to a technique well known on planet Earth. Here, water is used to generate the energy stored in coal, oil or gas into mechanical or electrical energy through what is known as a “heat engine”.

In a steam engine – the most common form of heat engine – fuel is used to heat water which then vaporizes at high pressure. This steam powers a turbine to generate electricity, or a mechanical engine to create its motion. Water is an ideal substance to use because of its availability and abundance. In addition, water is capable of undergoing phase changes (from liquid to gas, for example) within temperature ranges easily reached with the conditions present on Earth.

This whole situation changes drastically on Mars. Although water is available on the surface of the red planet, it is only found in its solid form. However, dry ice on Mars already exists close to its sublimation stitch – the temperature at which it changes directly from a solid to a gaseous state. The challenge is to harness the energy released by this change to power a heat engine and later develop a system that can power an inhabited colony.

The scientific experiment can be reproduced in any environment, such as in a kitchen. When a drop of water is placed on a hot surface and maintained at a temperature above 100°C, it evaporates completely. However, when the surface is heated above a certain temperature, known as the Leidenfrost point (check it out in the video below), the water does not evaporate. Instead, the drop sits in a layer of its own vapor and levitates to the top of the surface. This is known as the Leidenfrost effect.

This same effect allows dry ice to freely levitate above solid surfaces, and as it changes directly from a solid to a gaseous state, it also keeps floating through a newly formed layer of gas. So carbon dioxide plays a similar role on Mars than water does on Earth. It is a widely available resource that undergoes cyclical phase changes under natural temperature variations on Mars.

https://www.youtube.com/watch?v=UAMNDdOho8E

The idea is that in the near future, Mars could exploit all this CO2 to get energy from sublimation phase change like blocks of dry ice. One thing is certain: a possible manned exploration on other planets will depend on the ability to adapt current technological knowledge to the restrictions imposed in conditions different from those found on Earth and devise creative ways to exploit the resources available there. Who knows, the idea may inspire us to do the same thing here.

Source: Mashable