NASA just scored a badly needed win: The best potential evidence of alien life yet

The Perseverance rover found potential evidence of life on Mars. Three features make the rock promising, but NASA must bring it to Earth to study it.

• NASA's Perseverance rover has found potential evidence of ancient microbial life on Mars.
• Scientists must bring the rock to Earth for further study, but three key features make it promising.
• The discovery is a crucial win for NASA after a series of budget cuts and mission setbacks.

NASA has snagged a chunk of rock on Mars that could someday prove to be the first clear evidence of alien life.

To be clear, NASA is not declaring that it's discovered Martian life. Rather, its Perseverance rover has drilled a sample from a rock with attributes that could have come from ancient microbial activity, the agency announced Thursday.

To confirm their suspicions, scientists would need to bring the rock sample to Earth and study it in more detail.

"This is exactly the kind of sample that we wanted to find," Katie Stack Morgan, a lead scientist on the Perseverance mission, told Business Insider.

3 key features could point to alien life

The rock, nicknamed Cheyava Falls, has three critical features:

• First, white veins of calcium sulfate are clear evidence that water once ran through it.
• Second, the rock tested positive for organic compounds, which are the carbon-based building blocks of life, as we know it.
• Third, it's speckled with tiny "leopard spots" that point to chemical reactions that are associated with microbial life here on Earth.

However, both the organic material and the leopard spots could have come from non-biological processes. That's why scientists need to study the sample more closely on Earth to know for sure.

The rover has reached the limit of what it can learn about the rock.

"We're not saying there's life on Mars, but we're seeing something that is compelling as a potential biosignature," Stack Morgan said.

A biosignature is any feature that points to the presence of life.

"This is a very significant discovery," she added.

It's a much-needed win for the space agency. In recent months, NASA has taken hit after hit from budget limitations and technical errors across missions.

NASA needs this win

Earlier this year, the agency's first attempt to return to the moon since 1972 failed. The NASA-funded Peregrine moon mission, by the company Astrobotic suffered a fuel leak shortly after launch, forcing it to return to Earth and burn up in the atmosphere. (The next attempt, a mission by the company Intuitive Machines, also funded by NASA, successfully landed on the moon.)

Then, new budgeting decisions came down. NASA's budget proposal for 2025 effectively defunds the Chandra X-ray Observatory, which is still a highly productive and functional mission.

And just last week, NASA officials announced they were scrapping the VIPER moon rover that the agency has already spent $450 million to build. NASA plans to disassemble it and reuse some of the parts for future moon missions.

Meanwhile, two astronauts have been stuck on the International Space Station for 51 days because the NASA-funded Boeing spaceship that carried them there is leaking helium and having thruster malfunctions.

Even Perseverance wasn't spared. In April, NASA announced it was canceling its $11 billion plan to send a follow-up mission, called Mars Sample Return, to collect the rover's tubes of Martian rock and carry them back to Earth. That was the plan that could've brought scientists the Cheyava Falls rock sample.

Instead, NASA is asking companies to step in and propose their own cheaper, faster versions of the mission.

The Cheyava Falls rock especially needs the extra studying.

"This rock is also one of the most complex rocks we've seen on the surface of Mars. There is a lot going on in this rock," Stack Morgan said.

Is it aliens? Check the CoLD scale

For now, this discovery is just a "step one" on the seven-step "confidence of life detection" (CoLD) scale.

The CoLD scale is a rough rating of scientific confidence in any potential alien-life discovery.

"We've taken us up to the start of that scale, and I think that's what the rover was sent to Mars to do," Stack Morgan said.

A possible biosignature can climb to higher levels of confidence as evidence builds. For example, if scientists can confirm that known non-biological processes didn't create the leopard spots, the Cheyava Falls rock might ascend to step two or three.

But they need to get the sample to Earth first. And NASA needs to figure out how to do that.

"We're hoping that our most recent sample can play into the conversation about whether this effort is worth it," Stack Morgan said. "And we believe that it is."