Pavilion Lake, a 3.6 mile long, half mile wide body of water located in Marble Canyon, British Columbia, is famous for what visitors call “freshwater corals.” Even the fuzziest picture of them impresses; images recorded on a pipe inspection camera in 2001 reveal structures that are ancient-looking but lovely, like banks of hydrangeas. “Pavilion Lake is a special lake,” says Darlene Lim, a geobiologist who has spent much of her professional life there, and is now the principal investigator in charge of what NASA calls the Pavilion Lake Project. “There had been a lot of recreational diving,” Lim explains, “because the freshwater corals were an attraction. But it wasn’t until there was one man named Harry Bohm who actually put two and two together and thought there might be some kind of scientific value to these rock formations.”
Lim was preparing to start her post-doctoral studies with Chris McKay at NASA Ames Research Center when she heard about Pavilion Lake’s peculiar bounty. “Around 1997, I think, there was a small, little trip that was mounted with about five people,” Darlene recalls. She is an excitable woman—she says things like “the science is completely different” and she doesn’t sound like Jeff Goldblum in the first act of a movie where something’s gone horribly wrong. Even when talking about alien-looking lifeforms, she still makes you feel at ease. Over the phone, she is explaining this complex project to me, in essence, a passion that’s consumed the last fifteen years of her life, while reminding her toddler every few minutes that she’s on the phone. Somehow she does it all very quickly and very well.
She first learned of the lake, she says with a near-audible shrug, because word simply had gotten around, as if the astrobiology community were just a higher-minded garden club. Her mentor McKay thought immediately that its strange structures could be freshwater microbialites, a hunch which was both unusual and correct, and that led to a published paper in Nature in 2000, which established the peculiarity of Pavilion Lake, and set Lim on her path.
Let’s get small for a moment. Microbialites are organosedimentary structures that, in the words of the article, “abound” in fossil records. These rocks, corals, reefs, whatever you want to call them to avoid saying the word “microbialite” — pronounced mi-CRO-be-ah-light — are usually very old and very enigmatic; the ways in which they are produced are still unknown, in spite of conscientious work to date and analyze them. That there were microbialites in fresh water was remarkable, but so was the age of these particular structures. They seemed modern. More here The Most Surreal Lake in the World Is a Portal to Some Very Weird Things