It had been a pleasure for Axelrod to grind their faces into this fact, in court.
But then, the article said, PEPA had been joined by the Mars First! activists—who, conversely, didn’t want Earth to contaminate Mars. Both groups wanted the two planets to stay strictly apart, for opposite reasons.
“An unholy alliance of the absurd,” Axelrod was quoted as saying in the article.
What, demanded MF PEPA, was being done to ensure that indigenous life on Mars is protected from the ravages of Earth bacteria?
“Genocide, that’s what it is,” their spokeswoman exclaimed. “The so-called discovery of the New World all over again. European explorers brought diseases like measles, syphilis, and flu to the Indians, who died by the millions. Now we’re doing it again, to a whole planet!”
They cited Ray Bradbury, whose fictional Martians died from earthly diseases. That it was fiction was a fine point they didn’t appreciate.
And of course they sued Axelrod also.
Julia was amused by the article, but it also raised an interesting point. Did either planet threaten the other?
Traditional menace-from-space scenarios assumed an Earth-centric attitude. Earth attacked! Outer space invaders! The Andromeda strain, the Triffids, various evolved Martians, and lots of squishy aliens loomed.
And what was the fate of the fictional menaces from space? The Andromeda strain was done in by the pH of Earth’s ocean after being rained out of the clouds. H. G. Wells’s Martians succumbed to local microbes within a few days. The authors had reasonably assumed that a planet with a lively biosphere could put up a good fight.
But that was only fiction. Was there any real data to suggest that Earth could be at risk from an incoming Mars microbe?
First, it would have evolved in an oxygen-free, carbon-dioxide-rich atmosphere—anaerobic. Earth’s oxygen-rich atmosphere would be the first challenge, vastly reducing where it could live. Oxygen is a potent poison even to many organisms on Earth.
Then, Mars has lain beneath a thin skin of carbon dioxide, thicker in the past but always carbon dioxide, for four billion years. Even so diminished, it still contains much more carbon dioxide than Earth’s atmosphere. Even if Martian metabolism were not immediately poisoned by our air, there might not be enough carbon dioxide to sustain it.
And finally, Mars has been delivering rocks to Earth for billions of years, without any resulting Mars plagues. So far, Earthly diseases have all been from Earth. And that’s reasonable, because vastly different life-forms wouldn’t pose a biological threat to Earth life anyway.
She remembered the Nauga, a stuffed monster toy invented by some ad agency to push a particular type of leatherlike vinyl cloth. The really interesting thing about vinyl was that it had been created in the lab by chemists, and it was a novel arrangement of atoms, a new molecule. After it was introduced, it was found to be inedible to all earthly life. There simply were no digestive enzymes that could attack the vinyl configuration of atoms.
To truly alien life, Earth was filled with Naugas.
She didn’t think PEPA had anything to worry about.
But what about the Mars Firsters?
NASA had always tried to avoid cross-contamination. Spacecraft were assembled in a clean environment: an interplanetary condom.
Any microbes accidentally sent on the various landed robots should have succumbed to the aerobraking heat, then the cold, dry, and chemically hostile surface.
She remembered reading a short story about the first manned mission finding traces of microbial life on Mars, and then tracking it back to…a crashed Russian probe! A good story, and one NASA had tried hard to prevent from coming true.
But a manned mission was different. In their hab, they had brought a microcosm of Earth: four humans with all their tiny fellow travelers. Although we think we are individuals, we play host to colonies of bacteria, from our skin to the inner recesses of our gut. Not to mention the little creatures living between our eyelashes.
Four mobile Earth colonies and tons of food, frozen or dehydrated, carrying different microbes.
Even being careful, it was impossible to keep from liberating some organic material. Airborne dust blowing out of the hab included shed hair, skin flakes, human commensal bacteria, tiny mites that feed on human detritus, their waste pellets, and their bacteria. The built-in vacuum system in the hab kept up with most of the dirt, but there was no way to eliminate it all. The crew could not operate like a clean room for eighteen months.
And of course, when we arrived, we disposed of roughly a ton of frozen human waste, she thought. It’s out there now, orbiting near Mars. Despite what Axelrod told the media, it’s likely to come in for a landing sometime. When it enters the atmosphere, the plentiful microbes will most likely be incinerated crossing even Mars’s thin atmosphere.
But what if they aren’t?
Mars is covered with a reactive, peroxide-rich covering of busted-up crustal rock, sand, and dust that is essentially sterile.
Due to the wispy, ineffective atmosphere, sunlight rich in ultraviolet bathes the surface of the planet. Microbial life would be torn apart by vigorous chemical jaws. If Mars were lifeless, this was definitely the unwelcome mat to any bacterial life-form attempting a landing—apart from the cold and dryness. A hostile shore for life, indeed. But if Mars harbors life within, it was the first line of protection against tiny invaders. A rusty, defensive skin.
And what kind of life could exist on Mars? After four billion years of never having an oxygen atmosphere, it would definitely not be aerobic life. No, it would be anaerobic. But could we harm it?
We still think of Earth as the water planet, the blue planet, the planet of the oxygen breathers. “All life is ultimately dependent on the sun,” children were taught. “Food chains begin with energy from the sun that is harvested by the green plants.” But once again, it was our ignorance speaking.
Late in the twentieth century biologists found hydrothermal vents teeming with life deep on the ocean floor. The basis for the food chain was chemosynthetic bacteria, that had never seen the sun and couldn’t use its light. Soon after came discoveries of life in boiling-hot springs, very acid water, coal mines, and even microbes living inside rocks. Life permeated Earth, didn’t merely crawl its surface or swim in its seas.
All of the underground microbes were anaerobes, unable to exist within the reach of oxygen. That the biologists expected. But the biggest surprise was their DNA. Their genes were only 60 percent similar to all other life on the planet. They were the ancient bacteria, the archaea, persisting underground billions of years after the rise of the oxygen lovers. Did they retreat underground as the only refuge free from the deadly oxygen atmosphere? Is Earth’s deep underground a refuge, or the cradle of life?
She paused to consider. There may be more life below ground than oxygen users on top. They have the whole interior of Earth, while we are confined to the thin biosphere on the surface. After all this time, billions of humans haven’t touched the anaerobes on our own planet.
How could we few harm Martian life? Hell, we haven’t even found any. Well, there was always the vent, but how was she going to get back there?
And she seethed with frustration again. She sent a private, coded e-mail to her parents.
Hi Mums, Dad,
Thanks for the ETimes article. Earth is as crazy as ever. (Except for dear old Oz, of course. Did I tell you I saw Australia last month, through the scope?)
So far you Earthlings haven’t had much to worry about from Mars, but… Don’t think I told you my great news.
Just before Viktor’s accident, I managed to get a sample of organic stuff from the rocks around the lip of the vent. It was pretty dried-out and fragmented (it was frozen into some ice (!)). I’ve done a methanol extraction and run it through the GC and it’s definitely organic.
Of course I’ve got a million questions, and I want to confirm if it could have been contamination, because it seems pretty similar to Earth life.
