Sixty years after the first mission to Mars, Mariner 4, which aimed to capture images of the Red Planet, the expedition involving the Perseverance rover is already considered the most exciting by the scientific community and the closest to locating life outside planet Earth.
This is the assessment of the North American Space Agency (NASA) which, on the 10th, announced possible signs of biosignatures in a rock located in Jezero Crater.
In the Martian region where rivers and lakes flowed billions of years ago, a combination of minerals and organic material found in a rock called Chevaya Falls may indicate the existence of ancient life.
It would be a kind of microfossil, a result of microbial metabolism expelled after “feeding” on organic material, explained scientists from the space agency.
The news, which had been circulating in NASA laboratories for about a year, came to public attention now, after peer review by scientists and the publication of an article in the renowned journal Nature.
The findings were considered significant by an international team of scientists, but they are not conclusive, the article points out. This is because there is also the possibility that it is an abiotic process, resulting from a non-biological chemical reaction, that is, without the presence of life.
For Brazilian astronomer Rosaly Lopes, deputy director of Planetary Science at NASA’s Jet Propulsion Laboratory (Jet Propulsion Laboratory, in free translation), although the Perseverance analysis results are exciting, they will only be conclusive after checking the sample in earthly laboratories.
NASA’s interim administrator, Sean Duffy, said that bringing the sample back to Earth still depends on budget evaluation, time, and the technology that would be used in the retrieval mission.
Space Race
Even with the challenges to confirm the existence of life on Mars, NASA is full steam ahead in the space race, competing with countries like China, India, and Russia.
These countries join the race to see who unravels the big question about the Universe first: are we alone in this vastness?
In an exclusive interview with TV Brasil, Brazilian astronomer Rosaly Lopes discussed topics such as upcoming space missions led by NASA, where she has worked for over 30 years, and how close we are to answers about life in our Solar System.
“One of NASA’s biggest goals now, of our scientific community, is to know if life existed on other worlds.”
Check out excerpts from the interview:
Agência Brasil: NASA’s recent announcement about the mission involving the Perseverance rover and the potential biosignature in a rock on Mars excited the scientific community about the possibility of discovering life outside Earth. What was the mood among fellow astronomers and scientists involved in the research and other space missions in the lead-up to and after the public announcement of this news, considered by NASA the closest to finding life outside Earth?
Rosaly Lopes: That result had already been announced among scientists as soon as we discovered the rock, a little over a year ago, and the Perseverance robot’s instruments did the first analyses of the sample, called Sapphire Canyon. The difference now is that the scientific article has been published. And that means that, initially, before all the analyses had advanced, there was still a lot of doubt.
This is because the result found in the rock could perhaps be abiotic [resulting from chemical processes but without the presence of life], since the analyses have not yet been finalized. But now, the publication of the article in a scientific journal like Nature shows that the scientific community says the analyses are good. This makes this result not yet considered proof of life outside Earth, but it is now more accepted as a great possibility of being a sign of life – which we call a biosignature on Mars.
It is important to bring this rock back because the analyses the robot can do and those we can do here in Earth’s laboratories are not comparable. Really, to do a deep analysis and demonstrate that this is a sign of life, it has to be done here on Earth.
Agência Brasil: Although studies continue to be conducted, there are limits to the Perseverance rover’s operations on Mars. What is the main complexity for advancing the research?
Rosaly Lopes: It’s because many signals, like this one, can have abiotic explanations. That means there is no action or record of life; they are chemical processes that may have occurred. So it’s hard to prove, especially with the measurements the robot made, which are very limited. You can’t send a big laboratory to Mars because it would be too big and too heavy. So, there is still the possibility that this is abiotic, and to know for sure we have to bring the sample back to Earth.
Agência Brasil: The sample collected by Perseverance, Sapphire Canyon, comes from a rock located in a valley where rivers and lakes flowed billions of years ago. And the comparison with minerals resulting from microbial life metabolism in riverbeds here on Earth was essential for comparison parameters with the Mars sample. How can studying the origin of life on our planet help with missions to other planets and moons?
Rosaly Lopes: Research on Earth helps us a lot to investigate the possibility of life on other planets. So, for example, ancient rocks on Earth that show signs of life, that show that life existed in that ancient time on Earth, all the signs are there in the rocks. But applying that to other planets is really not easy because the conditions are different.
It is very important that we research if life evolved on another planet because to this day we don’t know if the evolution of life on a planet is something very easy or very difficult. Because we only have one example and that example is Earth. And you can’t do any statistics with just one example.
So, it is one of the biggest, let’s say, goals now of NASA, of our scientific community, to know if life existed on other worlds. But proving it, especially without bringing material back to Earth, is difficult because most of the time there are explanations that the process could have been abiotic, meaning it was not caused by life.
Agência Brasil: Let’s talk a bit about NASA’s next missions. We are on the way to important missions like Dragonfly, which will fly over Titan with a kind of super drone. This moon of Saturn has lakes and geology very similar to Earth’s. What stage of preparations are we at for this mission, considered the first aerial mission to another world?
Rosaly Lopes: The Dragonfly mission is a drone mission to Titan and has several instruments inside that drone, like a small laboratory to look for organic material and possibilities that life evolved on Titan, one of Saturn’s moons.
The mission has been confirmed and is now being prepared for launch around 2028, 2029. That depends a lot on budget, but the mission is already confirmed. That means NASA will provide resources for this mission. Dragonfly’s main goal is to find signs that life may have evolved on Titan. It will be a very interesting mission, even if it doesn’t find those signs of life, because it will study a lot about Titan’s geology, which is one of the most fascinating moons in the solar system.
Agência Brasil: The Psyche mission, launched in 2023, aims to investigate an asteroid, understand the origin of this metal-rich object orbiting it. Recently, we had information about an interstellar object with behavior considered atypical in terms of trajectory and speed, 3I/Atlas. But even with rare characteristics, and even theories about a possible unidentified object, according to scientific articles it is a comet from another solar system. Is there any concern about these celestial objects? Why do we need to know them better?
Rosaly Lopes: That’s very interesting. It’s not the first interstellar object we’ve found [before, Oumuamua was located in 2017; and 2I/Borisov in 2019]. And from observations, we think it really is a comet. But it would be very interesting to study this object because it comes from another solar system. And that would give us the possibility to know if comets in other solar systems are really the same as those in our solar system, or if they have different characteristics.
The problem is that we don’t yet have a way to quickly launch a mission to study these interstellar objects. When they appear, it’s a matter of months, not years, for us to prepare a mission. But we will use all possible missions we have, that NASA has, to take images of 3I/Atlas.
In fact, the Psyche mission is preparing to take distant images, of course, of this comet. There has already been talk among fellow scientists about the possibility of making a spacecraft that can be launched quickly if one of these interstellar objects comes again, but resources have not yet been obtained for that. The spacecraft would be stored until an interstellar object comes, and even then the trajectory could be difficult. So, there are really these problems that make it difficult to launch a mission to an interstellar object like this.
Agência Brasil: The Artemis mission returns to incursions on the Moon, including for the first time with an astronaut, Christina Koch. Scheduled for 2026, the mission will fly over our satellite, but according to Sean Duffy, NASA’s interim administrator, the idea is to leave the American footprint on the Moon again. How do you see the importance of this female representation at this moment? Do you believe this is an impetus to attract more girls and women dedicated to space sciences?
Rosaly Lopes: Artemis II mission, which Christina Koch is on, she won’t land on the Moon, she will fly around the Moon. I think the presence of a woman on this mission is very important because it inspires women and girls to pursue careers in science and technology. I already had a lot of interest in astronomy, but one thing that was a great inspiration for me was reading, in a Brazilian newspaper, an article about a girl who worked in Houston at the Johnson Space Center during the Apollo program. Her name is Poppy Northcutt, and I met her for the first time in 2019 because she left NASA and became a lawyer. Just seeing a photo and a short newspaper article about a woman working at NASA’s control center was a great inspiration for me.
So, it’s very important because it’s something women need to know they can do. It’s also the case with the first female astronaut, Sally Ride, who unfortunately passed away, but I think she inspired many other young women at the time. And one more thing about this issue that I always say is that women are at least 50% of the population. So, women, 50% of the population, should not be excluded from any field because that represents 50% of the talent and intelligence that can be used for the good of humanity.
Agência Brasil: Finally, the James Webb super telescope launched in 2021 has revealed images of the Universe never seen before. In your assessment, what image or discovery is considered the most surprising so far?
Rosaly Lopes: The James Webb images are wonderful and it’s very hard to choose one. It’s good to remember that when James Webb was proposed and then built, it cost a lot, very expensive and the budget went way up, it tripled (estimated cost of US$10 billion).
Many scientists were against doing it because it was too expensive and would take resources from other possible missions. But it was really a huge success. I think that nowadays all scientists agree that it was really worth it. It was worth the resources and the money invested in this mission. Sometimes, to carry out missions that cause the greatest advances in science, it is necessary to spend a lot of money. So, I think James Webb was an incredible success story, everything went right and the results are wonderful.
