In Michael Crichton’s terrific debut novel The Andromeda Strain a satellite crashes to Earth and triggers a horrifying disease outbreak. It had captured a deadly pathogen while in outer space—likely in a deliberate attempt to find new biological weapons—and although the outbreak is contained, the pathogen is shockingly virulent while it lasts.
The idea that there could be organisms capable of surviving the hardships of interplanetary space is not new. The concept of “panspermia” describes the spreading of organic life through space from planet to planet via various means of transportation, including comets and meteors. The idea has been around for a very long time, although in the modern era it’s most often connected to a theory by astronomers Fred Hoyle and Chandra Wickramasinghe which included the disturbing proposal that interplanetary organisms drift down into Earth’s atmosphere all the time, and may be responsible for periodic outbreaks of disease. Maybe at one time we would have scoffed at the idea that anything living could survive an environment of near vacuum, temperatures near absolute zero, and deadly radiation. We’re far less confident these days.
This week, in a plot point straight out of a B-movie, we learned that an organism frozen in Siberian permafrost for thirty thousand years is still infectious. Some French scientists got their hands on permafrost samples and decided to find out if they contained any aggressive organisms by using amoebas as bait. Sure enough, when the amoebas started to die, it was discovered that they were infected with a form of giant virus (a rare form very much larger than most). Thirty millennia as a germsickle apparently hadn’t done these bugs any harm. And, in fact, the French researchers had been inspired by a Russian team who’d resurrected a plant frozen in permafrost for a similar amount of time.
Why should we care? First of all, the researchers point out that global warming is causing huge areas of permafrost to thaw, and that process is likely to increase over the coming decades. Also, there’s a lot of new drilling and mining going on in permafrost zones around the world. Who’s to say that there aren’t virulent strains of pathogens from our ancient past waiting to be awakened, to wreak havoc in a species that has no immune defense against them? (My inner horror writer coming out there.) Secondly, if so-called “extremophiles” can survive being frozen for millennia, or endure the heat, pressure, and poisonous chemicals of deep-ocean volcanic vents, it seems naïve to expect that organic life could not survive the rigors of space travel, especially sheltered from radiation within bodies like meteors and comets. And Earth passes through meteor swarms and comet tails all the time.
Other experts will reassure us that we live with billions of micro-organisms around us all the time. They’re right—on the list of things to worry about, this probably ranks really low. But it may make you pause the next time you go to catch a snowflake on your tongue.