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Got Aliens in Your Nose?

This week the Royal Society in London is holding a two day meet-up for scientists to talk about the state of our search for extraterrestrial life.

At a lecture today, astrobiologist Paul Davies of Arizona State University told the crowd that he thinks aliens already walk among us. Well, maybe not walk—more like float, or wiggle, or however else bacteria may locomote.

microbes.jpg

AHHH!!! It’s an invasion!

—Buggy artwork by Jane Hurd, NGS

According to the Associated Press, Davies thinks that life from elsewhere in the galaxy has made its way to Earth at several points in human history. It’s possible, he says, that alien life is “right under our noses—or even in our noses.”

And why not? So many science-fiction writers seem convinced that if aliens of any shape or size were to come to Earth, they’ll be bad for humans and hence immediately noticable. Giant robots! Predatory stalkers!! Killer pathogens!!! Yes, Michael Crichton, I’m looking at you.

But that certainly doesn’t have to be the case.

For starters, consider the odds of an intelligent race of beings existing elsewhere in the universe.

One of the more popular tools for this thought experiment is known as the Drake Equation, proposed by radio astronomer Frank Drake in 1961. The equation goes like this:

N = R* • fp • ne • fl • fi • fc • L

Where:

N = the number of civilizations in the Milky Way galaxy with which we would be able to communicate

R* = the rate of formation of stars suitable for the development of intelligent life

fp = the fraction of those stars with planetary systems

ne = the number of planets, per solar system, with an environment suitable for life

fl = the fraction of suitable planets on which life actually appears

fi = the fraction of life bearing planets on which intelligent life emerges

fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L = the length of time such civilizations release detectable signals into space

Critics point out that some of the values for this equation are either constantly being revised or are near impossible to measure right now (imho, see fl, fi, fc, and L).

That means any solution would be based on pure speculation and therefore would hold little scientific value.

Still, if you fill in the equation with educated guesses, values for N range from 5,000 to 2.3.

I’d add to that equation some variables for whether the aliens we ping have invented faster-then-light travel and decide to pop by for a quick hello?

Now consider the likelihood of a few hardy bacteria hitching a ride on an asteroid, and some parts of that space rock somehow raining down on Earth.

ida-asteroid-ship.jpg

Ida: asteroid or alien “spaceship”?

—Image courtesy NASA/JPL

Known Earthly microbes can achieve some pretty amazing feats of survival, from withstanding millennia in ice to “resurrecting” their DNA after intense radiation blasts.

And just think of all the meteorites that have come crash landing in a field or through the roof of a doctor’s office, any of which could have been carrying galactic hitchhikers.

What’s more, the rocks themselves don’t even have to make it to the ground for their components—and maybe their cargo—to seed our atmosphere.

Finally, of the scads of Earth-based bacteria, less than one percent are known to causes diseases in people, according to the Mayo Clinic. That tells me it’s entirely plausible for any alien microbes that make it to Earth to be perfectly harmless, and thus better able to wander around undetected.

All told, I’m with Davies, and I’d wager that simple organisms such as benign bacteria will be the first aliens we encounter on our home turf.

Anyone want to take me up on that bet?

Comments

  1. Chris Cooper
    August 6, 2010, 5:18 pm

    “I’d add to that equation some variables for whether the aliens we ping have invented faster-then-light travel and decide to pop by for a quick hello?” – well who wouldn’t.
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  2. tickettogames
    August 2, 2010, 6:59 am

    I don’t clearly see where the author of this report get the idea of aliens being with us. Is Charles Darwin’s theory of evolution correct? I am not sure about other people, but I don’t clear see how animals and people have evolved. “This really is utter nonsense.” The author of the report should provide proof that aliens exist among us like it is clamed. “I believe there is as much truth to this report as Charles Darwin’s theory of evolution seriously.” “It is completely misleading.
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  3. diyRoberts
    July 30, 2010, 1:00 pm
  4. Moonface
    January 30, 2010, 3:48 am

    I don’t clearly see where the author of this report get the idea of aliens being with us. Is Charles Darwin’s theory of evolution correct? I am not sure about other people, but I don’t clear see how animals and people have evolved. “This really is utter nonsense.” The author of the report should provide proof that aliens exist among us like it is clamed. “I believe there is as much truth to this report as Charles Darwin’s theory of evolution seriously.” “It is completely misleading.

  5. chembuff1982
    January 27, 2010, 5:29 pm

    Although hypothesizing ideas is the leg work to scientific theories, this who idea is just frivilous guess work. Of course anything such as this has a chance of happening, but what is the probability of this happening, let’s not go by the above absurb fake formula either, which has no scientific basis. Rahther was say foreign bactrium, or anything of simple form was on or in an asteroid, etc. The life on the asteriod would have to survive light years or more in death defying space conditions, not to mention the time the asteroid would be in space, the heat and friction upon the asteroid in earth’s atmosphere, and the force of the collision. I do not know about you, but if I was a very small organism I would not want to risk my chances on that journey. Don’t forget intersteller collisions, and passing by very hot stars, large gravitational fields etc etc etc. A better equation would to find the possible places life could exist on planets, determine how if possible life would get off these planet and it’s probability, along with the probability of this life surviving in space and the trip through space. I wouldn’t bet $0.50 cents on those odds.

  6. mazoocat
    January 27, 2010, 12:57 pm

    very cute article :)

  7. Juana
    January 27, 2010, 1:43 am

    I enjoy watching shows on tv about the universe and all of the different organizations looking for intelligent life but honestly I don’t believe in aliens. I do know the formula states there are many stars with planets that can sustain life but I just don’t believe it.
    I also don’t believe there are aliens in my nose. IF, and it’s a big IF, there were how would we know they would be able to even survive in our atmosphere?
    I require solid proof to believe. I can’t see the wind but I can feel the breeze…I need to feel the alien breeze.