Earth is the only known planet in our solar system with life. In fact, it is teeming with it. But astronomers and scientists around the world hope to one day find life elsewhere. The only challenge is figuring out where to look.
That's where Hawaii comes in.
Scientists Greg Slater and Allyson Brady from McMaster University, with support from the Canadian Space Agency, are working alongside international researchers on the slopes of the Kilauea volcano in an effort to determine where future astronauts should look for past or present signs of life on Mars. The research is part of NASA's Biologic Analog Science Associated with Lava Terrains (BASALT) program.
While Saturn's moon Enceladus and Jupiter's moon Europa are also excellent candidates in the search for life — both have water — their distance from Earth makes them impractical targets.
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But then there's Mars — the planet next door. Scientists believe that, about 4.3 billion years ago, an ocean covered a large part of the red planet's northern hemisphere, and rivers and streams flowed. Most importantly, its magnetic field — which is barely there today — was healthy, allowing for the possibility of life to thrive on its surface.
If life did once exist on Mars (or still does), it hasn't made itself readily visible. Some scientists believe that if life exists in the present environment, it may lie far below the surface in order to protect itself from the harsh radiation that rains down on the planet, a result of Mars' weak magnetic field.
But on a planet where the surface is an expansive rocky desert, the challenge becomes ascertaining which rocks might hold the marker of life within them.
"If we're going to send humans to the moon to search, [and] we tell them, 'Go grab a rock,' they're going to say, 'Great..which rock?'" said Allyson Brady, a post-doc fellow at McMaster University. "You have the whole planet to choose from."
It's all about basalt
The life the scientists are searching for isn't the type created by photosynthesis. Rather, it might present itself as bacteria trapped in basalt rock.
On Mars basalt rock was formed billions of years ago by volcanic eruptions, and is similar to more recently formed rocks at Kilauea, making the area a great proving ground for researchers.
"We're making some assumptions, but you have to start somewhere," said Brady.
One of our handheld instrument capabilities is a spectrometer that generates mineral datasets so we can evaluate the rocks before we sample. pic.twitter.com/CiSYsoz4hQ— @BASALT_Research
The challenge is determining if the bacteria is biotic or abiotic — biological rather than physical. Some proteins, such as amino acids found on meteorites, can be abiotic. So the scientists need to look for biomarkers, specifically those using chemical compounds as energy. Rather than take in sunlight and convert it into energy the way plants and animals do, these types of "extremophiles" live in harsh environments utilizing other chemicals around them.
The Hawaiian mission was designed to simulate an actual Mars mission. The teams used aerial data similar to what they might get from a satellite orbiting Mars. Then, "astronauts" searched for basalt rocks, while the mission control team that would be on Earth had to endure the time-delay — that could be anywhere from five to 15 minutes — to communicate with the astronauts.
To compensate for the delay, the teams were tasked with various assignments throughout that day to ensure they weren't just sitting around awaiting an answer to a question about a particular task.
Another challenge is determining which types of basalt rock — porous or non-porous, for example — are most likely to contain evidence of bacterial life.
This is the second such mission, with an earlier one having taken place in Idaho's Craters of the Moon National Park in 2015.
While there are no firm plans to send humans to Mars in the near future, NASA is aiming to send the Orion spacecraft to Mars by the 2030s. SpaceX founder and CEO Elon Musk also outlined a bold vision to send humans to the red planet. But even if there are no human missions planned near-term, the research being conducted this month could still help future Mars-bound spacecraft, providing engineers and scientists with a better idea of where to set a rover or spacecraft down.
"There's a lot of good evidence that Mars was like Earth a long time ago," said Brady "I think it would be surprising if some microbial life somewhere didn't exist in the universe."