As Prof. Olszewski explains, Mars at the moment does not allow the kind of biological life that exists on Earth to function, for several reasons, the most important of which are two.

- The first is that it is too cold - on average the temperature on Mars is 65 degrees lower than on Earth. The second reason is that the atmosphere there is roughly a hundred times rarer than Earth's and almost entirely, about 95%, composed of carbon dioxide. There are also other reasons, such as the fact that there is virtually no magnetic field there, that the gravity is three times less, so it is difficult to say to what extent plants functioning on Earth would find their way in this lower gravity. However, these primary reasons are temperature and the pressure and composition of the atmosphere, says the scientist.

The aim of the project is to determine how existing atmospheric conditions on Mars can be modified so that plants brought from Earth can grow on the Red Planet. The research challenge is also to determine in what lesser time frame and where exactly it is possible for the first tree to grow on Mars. As the scientist points out, it is possible to go one step further and consider whether this could in some way be helpful when planning future missions to Mars, e.g. in the context of choosing where the next rover or lander should land, or when planning the first settlements or habitats on Mars.

Raise the pressure!

In the literature on the issue of terraforming Mars, i.e. making it similar to Earth, one can find more than a dozen hypotheses, among which one can also find science fiction ones - e.g. to ‘push’ Mars into an orbit closer to the Sun, then it will be warmer there.

- This type of solution is impossible for us, no matter how much we, as humanity, would invest. We do not have the technology to push an entire planet in the Solar System in any direction by even a millimetre. There are other ideas, I would say extravagant, such as deploying giant mirrors over the southern cap of Mars to illuminate the polar cap and melt the huge amounts of CO₂ that exists there in the form of dry ice - it would then melt into a gaseous form and warm the planet. Technologically this would probably be feasible, but the costs are astronomical, literally. Another idea is to bring in an asteroid, which would be composed of, for example, ammonia compounds, nitrogen, etc., and bring about an impact - an impact, causing a thermal reaction, releasing this gas, Prof. Olszewski explains.

Scientists from the Warsaw University of Technology are considering another concept in their model, i.e. the construction of a factory or rather factories of hyper-thermal gases. - An example would be freons, used in the former type of refrigerators, which are no longer allowed to be produced today. Their release into the atmosphere causes them to destroy ozone, thus increasing the ozone hole and causing the greenhouse effect, which is definitely undesirable on Earth. In contrast, freons, referred to in the professional literature as CFCs, released in the Martian atmosphere would make it possible to cause exactly what we do not want on Earth, namely the greenhouse effect. The atmosphere would heat up, the temperature would rise, which after a while would cause the polar caps to dissolve (their composition is dominated by CO₂, i.e. dry ice, although they also contain water ice). In the long term, this would thicken the atmosphere, release water, which is also essential for life, and then we could be tempted to have the first bacteria and very simple plants, which would start the process of photosynthesis, i.e. the conversion of CO₂ into oxygen, which, after a certain time, would not only thicken the atmosphere, but also saturate it sufficiently with oxygen to sustain life on Mars as we know it on Earth, explains the researcher.

This is no longer science fiction, but data science!

We will still have to wait for the results of the research. - We do not assume that this type of process can be realised in the perspective of our lifetime. This is a process that we can consider in the perspective of hundreds of years. It would probably mean the tenth rather than the third generation, but the start of this process would induce the kind of feedback that, after some time, could result in the functioning of life as we know it on Earth. Theoretically, without further thought, we would conclude that the first plants on Mars should appear somewhere in the equatorial region. But no. We have built very sophisticated simulation models to answer ‘what if’ questions. If we were to release more greenhouse gases, if we were to add CO₂, this planet would warm year after year. We count it not from year to year, but we count it from day to day - and there are 668 of these Martian days, they are called sols. The Martian year is therefore almost twice as long as on Earth. We can also perform calculations in which the calculation step is not a Martian day, but an hour.

The most important thing, however, is that we do not calculate these values on average for the whole planet, but divide it into areas called Goldberg polygons. We can imagine that Mars looks like a football, made up of hexagons and pentagons. In our model, we have 4002 such areas, each with an area of roughly 36 000 km², or about 1/10^th of Poland. There are 4002 such ‘polygons’, about the size of a voivodeship, evenly distributed, and for each of them, every day, and sometimes even every hour, we make ‘what if’ calculations - how the temperature, pressure, humidity, all the atmospheric parameters would change. We calculate what would happen after x number of years,’ adds Prof. Olszewski.

These analyses suggest that the first area that would warm on Mars is Hellas - a large former impact crater in the southern hemisphere, lying about 35 degrees south of the equator.

- This is surprising, but explainable, in the sense that Mars has a slightly different inclination to Earth - 2 degrees higher, and has a very eccentric orbit, or in other words a very flattened orbit. Earth's is similar to a circle, while Mars' is definitely more elliptical. When we put this together, it turns out that summer in the southern hemisphere is simply warmer, and as a result it warms up more easily. That is, we add greenhouse gases and CO₂, and the Sun does the rest. This model does the work on a powerful computing cluster on the CENAGIS platform in a matter of hours, while we model decades and sometimes even hundreds of years - that's how we find answers to questions about where it would go green.

How is Mars being studied?

The team relies on data that has been acquired by a number of missions, mainly American, about 90%, but also European, Chinese and Russian. Not only from the few rovers that have been or are on Mars, but above all from various types of orbiters, that is, artificial satellites orbiting Mars and taking measurements. On this basis, scientists know today's atmospheric conditions on Mars, the terrain, the composition of the atmosphere or the temperature. These data have been verified in situ - on the surface - by landers such as Viking or InSight, or rovers such as Opportunity or Perseverance.

- These are our reference data that tell us what it is like today. Based on this, we create complex computational models that allow us to initially reflect the state today and then answer the question ‘what if...’, e.g. what if we added a greenhouse gas, or if the CO₂ pressure became higher. We can also theoretically test in our model what would happen if we applied a - technically impossible - solution, e.g. pushing Mars closer to the Sun or changing the inclination of the planet's rotation axis. In our project, we are not basing it on theoretical assumptions, but on hard data acquired by various missions, mainly American, i.e. NASA,' stresses Prof. Olszewski.

Interdisciplinarity = plus and minus in one

The project is not funded by any grant. - It is our free time that we devote to this project - as a hobby, I would say. We tried very hard to get funding from NCN, but our problem is that the project is very interdisciplinary. From the point of view of scientists, interdisciplinarity is a huge advantage. Here we have geoinformatics, lots of strictly IT, computational issues, modelling, optimisation, cartography, visualisation, but also astrobiology, elements of chemistry, astronomy, botany - lots of aspects. For this reason, our project is hard to assign to a specific ‘drawer’, and grant programmes require just that. In short - this interdisciplinarity is not at a premium and it is difficult for us to get funding for such a project, so for now we are doing it ourselves, this project fascinates us. Of course, we are applying for various research funds, we are trying to find grants that fund research across the ocean - it is not that easy, because most EU projects are reluctant to allow funding from Americans and vice versa.

From the left: Piotr Pałka, PhD, Agnieszka Wendland, PhD, and Prof. Robert Olszewski

The research team consists of Prof. Robert Olszewski from the Faculty of Geodesy and Cartography (GIK), Piotr Pałka, PhD, from the Faculty of Electronics and Information Technology and Agnieszka Wendland, PhD (GIK). The team is supported by experts from other universities. Prof. Christian Körner from the University of Basel, who deals with alpine biology, shares his knowledge of what the minimum temperature must be, for example, for some plants to be able to function or how many days the temperature must not fall below a given temperature at night. Prof. McKay from NASA, in turn, inspired the team with his views to consider the ethical aspects of the project - whether we, as humanity, have the right at all to interfere with other planets and, for example, carry out colonisation processes there. The collaboration with San Jose State University, supported by NASA, is in turn about determining what Mars is like today - here the scientists are working with NASA's Melinda Kahre and San Jose State University's Alison Bridger. The scientists also emphasise that they would be happy to collaborate with more centres with similar projects.

A swarm of rovers

In the course of running the Mars terraforming project at one point, when funding from IDUB became available, the team decided to broaden their spectrum of research to include an ‘in the field’ component. The funds were used to purchase rovers and to create a Martian training ground at the WUT centre in Józefosław.

- In the second project, we are trying to develop such a vision of a swarm of small rovers that could perform measurements on Mars while still being supported by drones. With this - in relation to today's rovers, which are the size of a small truck, cost several billion dollars each, are expensive to send to Mars, and their failure means the end of the mission - we are proposing an alternative technology. A swarm of small rovers with heterogeneous sensors - that is, each one measures something different, a drone flies above them, or several, which support them in order to plan the mission appropriately and then they process the data together, and ready information is sent to Earth, emphasises Prof. Olszewski.

Mars training ground at the WUT centre in Józefosław

Dates?

When will we know the approximate date when the first tree will appear on Mars? - The model is fully ready, but in order to obtain such a concrete result, it is necessary to conduct hundreds, thousands of experiments, because each such model is based on dozens of parameters such as the orbit, inclination of the planet, CO₂ content, admixture of hyperthermal gases, the rate at which we release gases - there are many such parameters and they affect each other. Consequently, thousands of experiments are needed to get results. We are in the process of completing this work, compiling the results from the experiments obtained and preparing a publication. We also need approx. 2 years to reach the stage when our swarm of rovers will cooperate with each other and at the same time the rovers will also be fully autonomous.