Professor of geosciences Tullis Onstott has uncovered strange creatures hidden deep beneath the Earth’s surface — and they could tell us much about extraterrestrial life millions of miles above us.
“Deep Life” by Onstott, who was named one of the 100 most influential people in the US by Time magazine, takes us on a journey of discovery and exploration of the subsurface biosphere. Onstott chronicles the pioneering scientific search for microbial life hidden deep beneath Earth’s surface. This book introduces us to geomicrobiology, which is the study of the role of microbes in the field of geology.
Until the 1970s, scientists believed that the deep subsurface of our planet was a barren environment. But in the mid-1980s, Frank Wobber, head of the Subsurface Science Program (SSP), claimed that the subsurface was not sterile and was inhabited by bacteria and eukaryotes. He also believed that the subsurface life rivaled that of the surface of our planet.
“It is a historic fact that in the space of 20 years scientific consensus concerning deep subsurface life on Earth and all its extraterrestrial implications switched from incredulity to active scientific endeavor,” writes Onstott.
Journey toward the center of Earth
Onstott takes us on a journey to discover and understand the limits of life beneath the surface of our planet. One of the most interesting expeditions is a descent into the East Driefontein mine in South Africa to observe deep and potentially very ancient microbial ecosystems.
Onstott’s vivid and detailed description gives us the feeling that we are actually taking part in this journey toward the center of the Earth.
A cage is the only means of descent into the mine. It is a triple-decker elevator car that hauls men and supplies to great depths and back. It looks like a large steel box restrained by rollers, similar to those on a roller coaster, and guided by a system of vertical steel rails.
“The cage quickly gained speed, tugging at its greased rail restraints as it slid along in a vaguely controlled free fall… I felt the increased g-force as we pulled into our station, and just when I thought the cage had gone too far, the floor picked me up and then dropped me down as if I was tied to a big yo-yo… Four minutes had elapsed since we had traveled a mile and a quarter, more than four times the ride from the top of one of the World Trade Center Twin Towers… We were now below sea level and as deep as the deepest mine in North America, yet this was only the halfway point… We stepped into the secondary cage and proceeded all the way to shaft bottom at 50 level, about 12,000 feet below the surface and 6,000 feet below sea level… The deeper you go, the hotter it becomes. Even though East Driefontein is a relatively ‘cool’ mine, the air temperature would rise to 48C (118F) without the ventilation,” writes Onstott.
Creatures of the deep
The deep subsurface biosphere abounds with only recently discovered, and many incompletely understood, organisms.
Take the recent discovery of Halicephalobus mephisto, a type of roundworm, by Onstott and Dr. Gaetan Borgonie. Borgonie, who specializes in the study of roundworms, or nematodes, was the first biologist who sought to go down into the bowels of the planet to collect samples. Roundworms can be very small — a millimeter or less — while some reach lengths of three feet. Nematodes can survive in extreme environments. They even survived the breakup of the shuttle Columbia: Several months after the explosion, NASA found canisters and discovered that nematodes inside them were still alive.
Borgonie joined Onstott in South Africa. In a filter sample from a one-mile-deep borehole in Beatrix Gold Mine, he was able to locate a nematode. He provided this microscopic worm with food, until it was able to produce an egg, and then one miraculous day the egg hatched into a beautiful baby nematode.
From the depths of Earth to Mars
The discovery of this species in the bowels of the Earth shows that the subsurface biosphere has not revealed all its secrets: The hunt for deep life has still many surprises in store. It might even help us discover whether life exists on Mars.
The search for the hidden biology two miles underground in a South African mine or in Canada’s Arctic region is an interesting topic. The author, a brilliant geomicrobiologist, shares his passion for this relatively new field of research. It is difficult to ignore the infectious enthusiasm that permeates the narrative; however the liberal use of technical and scientific language may be off-putting for some readers. It is an interesting subject for the general public but unfortunately not written for the lay reader.
• life.style@arabnews.com
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