f you have any questions about Mars, Jim Bell is one of the most suitable people to answer them. This planetary scientist and professor at Arizona State University has been heavily involved in NASA's Martian missions since the 90s. And although he has also participated in the development of other robotic spacecraft that have explored comets or the Moon, the former director of the Planetary Society of the US confesses that he is passionate about the red planet.
"It fascinates me for a combination of elements. If you see photos of Mars, it looks like a familiar place, it reminds you of Earth, but at the same time, it is very hostile, very cold, and its atmosphere is very thin. Today there is no oxygen or water on its surface, but long ago it was much more similar to Earth. And compared to Jupiter or Neptune, it is close, it takes between six months and a year to get there, so we can send many missions, one after another, based on the result of the previous mission, and build a program to search for evidence of past life and a habitable environment, which is what both NASA and the European Space Agency (ESA) have done," he explains during an interview.
The meeting with this newspaper takes place in Puerto Naos, on the island of La Palma, where he participated this week in Starmus, the largest science and music festival: "I lived in a place with a very dark sky like in La Palma. Well, not as dark, because this is incredible. But with the telescope my parents gave me when I was 12, I learned to know and love the sky," recalls Bell, who says he is "very excited" to be able to visit during this trip El Roque de los Muchachos of the Institute of Astrophysics of the Canary Islands (IAC), one of the most important astronomical observatories in the world.
Those first astronomical observations he made as a child in Coventry (Rhode Island) with his first telescope and the programs of Carl Sagan cemented a passion for space that was born watching astronauts on the Moon on TV - he was seven years old when the last Apollo mission concluded in 1972. "I remember watching them from home driving the rover (robotic vehicle) on the Moon, it was very inspiring for me. And as at that time my country was trying to win the Cold War against the Soviets, it was big news and very exciting."
Years later, he would have a very prominent role in the construction of the legendary rovers that have been exploring Mars in recent decades. The twins Spirit and Opportunity - launched in 2003 - were designed to work for three months but lasted many years: almost 15 in the case of Opportunity, which succumbed to a large dust storm in 2018, while Spirit explored Mars for six years, until it got stuck in a sandy area). Currently active on the red planet are Curiosity, which arrived in 2012, and Perseverance, since 2021. And both are in good shape. "It is difficult to predict how long an instrument will last, but once they reach space, if they start working well, they usually work for a long time; it also happens with communication satellites. Other times they have problems as soon as they arrive. So we have been very fortunate with the Martian rovers," he says.
But for these robotic devices to explore and make amazing discoveries with their portable laboratories, they must first successfully land on Mars, something very complicated. So much so that the phase of entry into the Martian atmosphere, descent, and landing is known as the "seven minutes of terror". How does he experience those critical moments when the entire mission is at stake? "It is very stressful, just like the launch. You work for years on your precious machine and you put it on top of a bomb. It has to arrive safe and sound and then land on the surface. You always hope that things will go well because everyone has done the maximum number of tests possible. But the only real test takes place when you launch. I once described it to my family like this: you see the rocket take off or the vehicle land and you feel like singing and dancing, but at the same time, you feel like vomiting because you are very nervous," describes the researcher, who has also participated in some missions that failed. "One crashed on Mars, and another one that was going to explore comets exploded in Earth's orbit. I assure you it is not fun at all."
While humanity manages to overcome the obstacles for astronauts to one day travel to Mars, the rovers are paving the way, looking for traces of past life on this planet, water, and exploring the viability of building a future human colony. "We know for sure that Mars had water and was much more similar to Earth about 3.4 billion years ago, at the beginning of the history of the Solar System. As soon as Earth cooled enough for oceans to form, life emerged; perhaps the same happened on Mars, we do not know because unfortunately, possible evidence of it is not visible on the surface. If there was life on Mars, it was probably simple, unicellular bacteria."
Every time Curiosity drills a hole or Perseverance collects a sample, says Bell, "they could discover something incredible, some evidence of a cell, a fragment of DNA, or some other molecule that can only be made by life as we know it. It has not happened yet, but we are getting closer," he assures.
For example, in March, the discovery of the most complex organic molecules found to date thanks to Curiosity was announced. Although they are very ancient, about 3.7 billion years old, they have been preserved. "The authors of the study have been very careful and emphasize that they are not proof of past life, but they are the most complex molecules found," he states.
Water, he explains, can remain in the subsurface of Mars, as it is believed that much of the water that was there was probably lost because there was no magnetic field. "We know that there is water in the subsurface of the icy poles, at high latitudes. If we were to drill there, we could extract ice cores, as we do in Antarctica or Greenland, which would give us information about the climatic history of the planet. And that water would be critical for future manned missions to Mars."
"The surface is very hostile to organic molecules, to any molecule really. There is a very thin atmosphere, high-energy radiation all the time, almost no water, and yet these molecules can survive. And it must be considered that they may not be biological, as we have seen similar molecules, long hydrocarbon chains, in meteorites coming from deep space," clarifies the scientist, who explains that his theory is that "at greater depths, one could access material even more isolated from the hostile surface."
Furthermore, it does not rule out the possibility of current life on this inhospitable world, in the depths of the subsurface, or on some moons of the outer Solar System: "It depends on how much water there is, whether it is liquid, or what energy sources are accessible. It is not crazy to think about the existence of life in the deep subsurface in various places in our solar system. It used to be crazy to think about it, but now it may be plausible. The difficulty lies in getting there, accessing the deep subsurface."
If there are no further delays, ESA will launch the ExoMars mission in 2028 with the Rosalind Franklin rover, equipped with a drill that will allow drilling into the Martian subsurface up to 1.7 meters deep. "It is much deeper than any vehicle has drilled on Mars," but to find that possible current life, Bell says, one would have to penetrate much deeper into the subsurface, "hundreds of meters or hundreds of kilometers."
Therefore, current missions focus on searching for traces of past life. If the unicellular bacteria that they believe could have existed billions of years ago are still there, he explains, "they must be in the subsurface, where there could still be hot and stagnant water. On the surface, the traces are probably very subtle, chemical signatures of mineral isotopes that need to be extracted with very careful experiments. We can conduct some of these experiments with landing modules and exploration vehicles on Mars, but these laboratories are by no means as good as those on Earth. That's why we want to bring back the samples."
Specifically, the pioneering robotic mission Mars Sample Return, designed to collect samples from the Martian soil and bring them back to Earth for analysis, is one of those threatened by the budget cut that the Trump Administration is planning for NASA's scientific missions department, up to 47% by 2026, according to internal documents that have come to light in recent weeks.
"It is very alarming. In the US, the presidential administration proposes ideas for the budget of the following year, and what has now been leaked are unofficial documents proposing significant budget cuts. The official documentation will arrive in the coming weeks. We will see if it remains. There has certainly been a lot of resistance to these types of cuts in many different agencies," explains Bell, clarifying that "it is actually a proposal for cuts because in the US, the president does not make the budget, but the Congress, which sometimes agrees with the president and sometimes does not," he states.
In his country, they are already mobilizing to stop this budget cut proposal: "Many people who, like me, work with organizations such as the Planetary Society of the US, were in Washington a few weeks ago talking to members of Congress and their committees about the importance of NASA, the importance of exploration, international collaboration, and the commitments we have made with other countries, and that other countries have made with NASA. And I think the congressmen understand that NASA is the best brand Americans have in the world. I believe it is. In airports and in many countries, you see people wearing agency T-shirts because it is a projection of American soft power and aspirations, of the incredible things people can do," he explains.
And all this, he adds, comes from Congress funding. "Congress estimates, for example, that out of every dollar that comes in through taxes, 0.4% goes to NASA. It is a very small amount, but there are three hundred and something million Americans contributing, so you get $20 billion a year to do incredible things," he explains. "Why is it worthwhile for the American taxpayer? Because we make discoveries, rewrite textbooks, and lead the world in this field," he defends.
The scientist, however, is confident that these budget cuts will not ultimately affect NASA's scientific programs and that they will be compatible with Trump's goal, stated during his inauguration speech, of sending a manned mission to Mars. This is what the owner of SpaceX, Elon Musk, leading the US Government Efficiency Department, desires the most. The billionaire intends to launch one of his Starship spacecraft, unmanned, towards the red planet within two years, and in this decade, a manned spacecraft.
Is it possible? we ask Bell: "I have learned in the last decade never to bet against SpaceX. Don't bet against SpaceX because they do incredible things," he assures. "There are many technological obstacles to overcome before the Starship spacecraft are ready to go to the Moon, not to mention Mars. But it is good that they are working on it. Personally, I believe we need to remember how to live and work on a planetary surface. We briefly visited the Moon 50 years ago, now the technology and intention are completely different, it is not just about planting the flag and rushing back, at least not on the Moon. The intention is to figure out how to stay there long term, do some science," he points out.
Over time, this specialist points out, "the Moon will become part of Earth's economic sphere, and there will be commercial reasons to be on the Moon, tourism, resources... So all that I think will happen, will happen. And the frontier, at least for NASA, is Mars."
According to this planetary geologist, it is indeed possible to send a manned mission to Mars without returning to the Moon: "It depends on how long you want to stay, what you want to do there, and what your goals are. China talks about doing quick missions, planting the flag, and returning. I think it would be more beneficial for us to learn to stay in space for a long time."
For astronauts to safely reach Mars, they will need to be protected from space radiation and supplied with everything necessary during a one-way trip that will last at least six months: "They will need oxygen, water, food, things to do to avoid going crazy. You know, a school bus for six months. There are a lot of psychological and physiological problems that need to be solved beforehand."
What will it take to get to Mars? Is it a matter of money? "I think it is a combination of money, political interest, citizen interest, and the desire to achieve it," he summarizes. "The main reason the US went to the Moon in the 60s was to demonstrate the superiority of democracy over totalitarianism, and part of that motivation exists today, but so does pure inspiration for children and other nations. There is also an economic motivation because there are technological problems that need to be solved, and solving them will help us solve other problems on Earth."
Bell believes that if there is a real commitment, humans could walk on Mars in the 2030s. "It would take a decade, probably. Since President Kennedy said in 1961 that we were going to the Moon, it took eight years until we achieved it, without technology or a previous plan. And now we have a lot of technology and experience, but it would have to be a national and international priority because we should not do it alone. We should combine our resources, combine our money and our neurons. And this is now difficult due to the world political situation," he acknowledges.
Regarding the allocation of funds for NASA missions, he admits to having mixed feelings: "Of course, I would like astronauts to go to Mars, but also for there to be more robots to scientifically study the planet and bring back samples. If the cost is that NASA does nothing else, or that no other important science can take place in the US because all the money must be spent on that single objective, I don't know if I would make that change, I don't think so," he reflects.
For now, we will have to settle for continuing to learn about Mars through the eyes of robots and some movies: "In my opinion, The Martian is the one that comes closest to reality. Not 100%, but I would say 80%," he opines about the film starring Matt Damon. "Some things have been exaggerated and are science fiction, but some of the technologies shown were very reasonable, and the isolation that the astronauts will feel is also realistic," says Bell, who points out, however, that the sandstorms are not as depicted in the movie. "Although Mars is very windy and there are large dust storms, due to the atmosphere being so thin, the winds do not have that force to move or knock things down." I talked about this with Andy Weir [author of the book The Martian, which was adapted into the movie]. He said he knew it but needed to show a man vs. nature struggle. The impact of a meteorite nearby would be more realistic, but we have not experienced it and do not know what it feels like, but we do know what a gale feels like. But well, it is logical and I think it's fine because it's a science fiction movie."