From Earth's Caves — A Better Understanding of Mars
Penny Boston's job could've been ripped straight out of the pages of a pulp science fiction novel.
Who else spends time in places like the Cave of the Crystals or the Cave of the Lighted House?
Who else braves environments dripping with sulfuric acid or crusted with creatures called snottites?
Who else can say they've set foot on the Snowy River, the longest-known cave formation in the world — one with no end in sight?
If you're picturing book covers illustrated with alien landscapes and fantastical creatures, you're really not too far off the mark.
"I have seen wonders beyond description," said Boston, a professor of cave and karst science at New Mexico Tech, during her keynote address Nov. 14 at the NASA Innovative Advanced Concepts (NIAC) Fall Symposium in Hampton, Va.
For all the outlandish-sounding places she's been and grotesque life forms she's handled, though, Boston's work is very much grounded in real science. She hopes that by studying extreme environments and strange life forms on Earth, she might help us gain a better understanding of what we could potentially face on places like Mars.
"We're looking for templates," she said. "We're looking for models to inform us about what we are wanting to look at and what we're trying to plan missions to look for."
Boston has looked for those templates in some far-flung places. In a cave beneath the scorching, arid desert surface of Saudi Arabia, for instance, she saw deep, vast pools of crystal blue water.
According to Boston, the drastic difference between the surface and subsurface in the Saudi Arabian desert probably isn't unique in our solar system.
"What you see on the surface is one planet," she said. "But you have to infer that there are a whole set of subsurface requirements just like we have here on Earth that may be very radically different from the surface."
A lot of the life that exists in those radically different environments is weird and microbial. When talking about some of the strange cave organisms she's studied, Boston uses words like "goopy," "moon milk" and "fluff."
Similar goopy, fluffy organisms may be lurking under the surface of Mars.
"If it's not big and biting us or our rovers on the ankle, then it's probably going to be small and cryptic," she said.
Here on Earth, those cryptic microbes grow in droves in places like the Cave of the Lighted House in Tabasco, Mexico. Rich in hydrogen sulfide gas, which is poisonous to humans in amounts of more than 10 parts per million, the cave is home to unusual organisms like phlegm ball matts and snottites, which "look like what comes out of your two-year-old's nose when he has a cold," said Boston.
There's also strange stuff growing in the Cave of Crystals in the Naica Mine of Chihuahua, Mexico.
There, the conditions are so hot and humid that a human body can't cool itself. It's a dangerous environment that requires visitors to wear ice vests. But for Boston, the risks are worth the rewards. The giant gypsum crystals inside the cave are so extraordinary that when Boston first saw a photo, she thought it might be a Photoshop hoax.
Today, 65 cultures derived from fluid inclusions in the crystals, cultures that had been trapped for tens of thousands of years, are growing in labs.
"The potential for long-term storage within geological materials is untapped," said Boston. "We'll continue to try to study this and push in the direction of how long organisms can survive within geological materials."
Those studies, Boston believes, will have consequences for our exploration of Mars.
In the meantime, Boston is keeping her focus on Earth, because even as the Curiosity rover sends us postcards from the Martian surface, we still have plenty of mysteries to solve in our own backyard.
"Right here on this planet under our feet, even when we study them for years, we have aliens that we can't identify," she said.
And when we get better at identifying our own aliens, we'll be better prepared to study the ones we run into on other planets.
NASA Langley Research Center