6 days ago
Life on Mars? Paper co-authored by LANL scientist says more terraforming research needed
It might be surprising to hear planetary scientist Nina Lanza use the word 'disappointing' in the same sentence as 'Mars.'
After all, the Los Alamos National Laboratory researcher has dedicated her entire career to the Red Planet.
Lanza personally has been fascinated with Mars since seeing images taken of the surface during the 1997 Pathfinder mission. But she said the earlier Viking missions in the 1970s were a letdown to many, leading to a longtime lack of interest in Earth's rusty neighbor and an approximately two-decade gap before the next Mars mission.
'We saw a bunch of rocks,' Lanza said. 'That's not actually unexpected — that's what planets are made out of. But there was so much hype, I think, built up from 100 years of study of Mars as having canals, with these civilizations moving water. All of that was built up so much that when we actually saw the surface of Mars as it is, people couldn't help being disappointed.'
That's changed. Lanza, who recently co-authored a perspective paper on the potential to terraform Mars, said the fourth planet from the sun is going through a renaissance. Technological advances, Space X and Andy Weir's The Martian have returned Mars to the forefront of the public's imagination.
An idea popularized by astronomer and planetary scientist Carl Sagan in 1971 is having a renaissance as well: terraforming.
'Mars has been a lot more of a complex, dynamic place than we really gave it credit for when we first landed with Viking,' Lanza said. 'It's a place with a lot of resources. It's a place that I think we can, yet again, start to imagine ourselves going to and being there on the surface.'
Nina Lanza X post
Nina Lanza, a Los Alamos National Laboratory scientist who has dedicated her career to Mars, documents milestones in red planet research on her X account.
Her perspective paper, published in Nature Astronomy, asks two main questions: Can the currently inhospitable Mars be warmed enough for life? And, once that question is answered, another arises: Should it?
The paper makes a case for more terraforming research. But there's a long way to go before the red planet turns green.
Terraforming has, in the past, been relegated to the pages of novels. A 2018 study published in Nature Astronomy suggested there's not enough readily accessible carbon dioxide left on Mars to warm the planet sufficiently with greenhouse gases alone.
But Edwin Kite, associate professor of planetary science at the University of Chicago and another co-author on the perspective paper, said there's been technological advances in the past couple of years that have made terraforming seem more in reach.
'It hasn't been a goal in the past because it's been seen as science fiction,' Kite said. '… It's only in the last few years that there's been a big increase in our ability to move mass around the solar system, and these new warming efforts that make it seem like something we might actually do — as opposed to science fiction.'
A friendlier climate
New Mexico and Mars are both deserts, Lanza noted. Water scarcity is a big problem in the Southwest, but it pales in comparison to the lack of readily accessible water on Mars. The majority of the planet's water reserves are in its coldest parts, according to her paper.
Mars was likely once a warmer, wetter place, but that's not the case now. Cold, dry and radiation heavy, its surface is 'worse than the worst deserts on Earth,' Lanza said — more akin to the frozen desert of Antarctica.
New Mexico is 'like a tropical jungle compared to Mars,' she said.
Mars also has a thin atmosphere.
Nina Lanza
'Right now, Mars is not a great place to go if you're a human — or any kind of microscopic life. It's a really harsh environment,' Lanza said. '[But] you can make it less harsh, even if you can't recreate Earth.'
Kite said there's several potential ways to address these challenges and warm Mars. For example, in a 2024 article co-authored by Kite, researchers looked at using artificial aerosols made of materials readily available on the planet's surface, rather than greenhouse gases, and found it potentially could warm the planet more effectively.
The recent perspective paper also delves into using solar sails and other methods to potentially increase the planet's average global temperature by 'tens of degrees' over the course of several years.
Raising ethical questions
But 'can' and 'should' are two different words.
The paper delves into the ethics of terraforming — and putting humans on Mars in general.
'Indeed, any movement of humans beyond Earth raises ethical issues,' the paper states. 'It is a trope of science fiction that, even though humans have already restructured Earth's land surface, nitrogen cycle and so on at the planetary scale, attempts to do the same for other worlds will be seen as dysfunctional.'
Much of that swirls around a lingering question left unanswered by David Bowie: Is there, or has there ever been, life on Mars?
If there is, researchers argue, that totally changes the discussion about terraforming.
While the planet appears dead on the surface, Kite said, there could be life lurking in the deep subsurface.
And Lanza said rocks studied with Mars rovers have displayed 'fascinating chemistry' that could be an indicator of ancient life on Mars.
'If we had seen it on Earth, it wouldn't be a question to us that this was formed by life,' Lanza said. 'But because it's on Mars, it requires much, much larger burden of proof.'
In some ways, the perspective paper is a call to action: More research is needed.
Such research could also inform our knowledge of Earth, Lanza said, noting the planet's changing climate. Mars has gone through its own climate change, becoming drier and colder; terraforming would be yet another change.
The surface is also much more ancient than Earth's, Lanza said, allowing for a more complete geologic record.
But, while similar, Mars and Earth have fundamental differences, Lanza said. Terraforming could make them more similar, but Mars will never become a copy of Earth.
'Earth is unique, Mars is unique, and Mars will continue to be unique,' Lanza said. 'Planets are never going to be identical.'
Nina Lanza
Stalled sample mission
Evidence of life could be in samples of matter collected on the planet's surface, which NASA had planned to return to Earth for study.
The Mars rover Perseverance has been collecting samples, but they might not make it to Earth. An early proposed budget report said costly missions like Mars Sample Return, described as 'grossly over budget,' should be terminated. The need for research on samples would be fulfilled by human missions to Mars, the report stated.
It's not the first time the high cost of the mission has raised eyebrows. An independent September 2023 report expressed concerns over an 'unrealistic budget and schedule expectations.'
The mission was unlikely to meet proposed timelines, the report said, and the proposed fiscal year 2024 budget wouldn't be enough to get the program off the ground.
However, the value of the samples is high, the report stated. The return would 'revolutionize' the understanding of the inner solar system and answer 'one of the most important scientific questions we can answer' — whether there is, or was, life off of Earth.
But NASA struggled to communicate the importance of the mission to the public, the report stated.
Last year, then-NASA Administrator Bill Nelson said the agency was working on a plan to address the issues.
'Mars Sample Return will be one of the most complex missions NASA has ever undertaken. The bottom line is, an $11 billion budget is too expensive, and a 2040 return date is too far away,' Nelson said in an August news release. 'Safely landing and collecting the samples, launching a rocket with the samples off another planet — which has never been done before — and safely transporting the samples more than 33 million miles back to Earth is no small task. We need to look outside the box to find a way ahead that is both affordable and returns samples in a reasonable timeframe.'
Nina Lanza
Lanza said the Mars Sample Return mission is critical. She doesn't see human missions as an alternative — the human presence can disrupt the planet's landscape, potentially obscuring any record of ancient or current life.
The samples can also help protect humans, and their equipment, on future Mars missions, she said. She pointed to lunar regolith, sharp dust on the moon that can be damaging to breathe.
'Understanding what Mars is made out of and how it might pose any particular hazards to health, that's really important if you're going to send people into that hazard,' Lanza said.
Kite had a different perspective. Although the samples have been 'judiciously chosen,' he said, they won't answer every question about Mars — and the high cost makes it unlikely other sample return missions will be approved.
'Even if it had been pursued, it would have been the last sample return, because taxpayers would never sign off on a second one that was very expensive,' Kite said. '… Making it that expensive is a very eggs-in-one-basket approach, because it seems that your first bunch of samples will answer all questions about Mars.'
He added, 'I don't think that's likely.'
