Where are all the aliens?

“Where are all the aliens?” asked Enrico Fermi in 1950. Fast forwards seventy years, just about my entire lifetime, and we’re asking the same question: despite enticing hints, we have yet to find direct evidence of extraterrestrial life. There is a good chance that that will change in the  coming decade.

First, I’d like to document my attitude towards extraterrestrial life when I was a kid. Let us now fast backwards in time to a time not long after Enrico Fermi said his famous assessment of life beyond the solar system. I was almost an adolescent. My uncle Arthur (1898-1958) was building a little retirement cottage in Forked River, New Jersey—the reality of stomach cancer, alas! prevented the realization of his dreams. Our family visited the nearly-completed bungalow many times before my uncle’s death in 1958.

The incomplete kitchen walls were covered with cardboard. All visitors were invited to sign their names on the wall. My brother, Robert, wrote the following:

Arthur Dorsett

3^rd Canal Drive, Mars

Reminiscence of Percival Lowell! Lowell was an American businessman and amateur astronomer, who became famous for his assertion that Mars was inhabited by intelligent life. He saw—or at least thought he saw-- a pattern of lines on Mars that he assumed were canals that brought water from the poles to a dying civilization.

At the time of my brother’s writing on my uncle’s wall, it was still possible to believe that Mars possessed intelligent life. These hopes were dashed when Mariner fly-bys revealed Mars to be a frigid, red desert.

(I remember listening with interest to a re-broadcast of Orson Welles’ 1938 radio play, War of the Worlds, based on a book by H. G. Wells. The original broadcast  caused a great deal of panic by its realistic presentation of a Martian invasion.)

By the time of my yearly adolescence, however, there was little hope that extraterrestrial life would ever be found in our solar system. Now I’m not so sure.

I had been fascinated with Mars. I remember writing with fascination about the red planet and its two moons, Deimos and Phobus. I could almost imagine these two little moons, probably asteroids captured long ago by Martian gravity, passing overhead, no brighter than first magnitude stars, as I imagined myself standing next to a Martian crater. I had been convinced, however, that Mars was a lifeless, frigid desert.

(Ditto with the possibility of life in the rest of the solar system. Who could imagine life on a planet other than ours? Possibly on moons? In our solar system, however, the majority of moons are around gas giants with atmospheres and temperatures that made life as we know it impossible. Or so we thought.

In modern times, the possibility of life on Mars is once again a serious possibility. If life actually exists on that planet, however, there will be no little green men, but, at best, microbial life.

Recent flvbys over Mars have indicated that in the remote past, that  is, billions of years ago, Mars was a much more habitable planet than it is now. There is evidence that the planet once had a surface ocean, perhaps even a kilometer deep. Photos reveal dry riverbeds, shorelines, and strong indications of water erosion. Unfortunately, Mars has a very thin atmosphere and no magnetic field to protect life from cosmic rays. The surface water dissipated into space long ago, but there is evidence that water  exists underground. There are probably aquifers beneath the surface in many areas of the planet. There is evidence of seasonal variations of methane in the atmosphere; methane is a biomarker for life on earth. There is other indirect evidence that has convinced many scientists that life either once existed on the planet or has gone underground. We’ll see.

Perhaps soon: A Mars rover is set to drill about ten meters into the surface, and will analyze the soil for signs of fossils or living organisms.

There is also the theory of panspermia, the premise that life began elsewhere in the universe and came to earth via a comet. It has been proven that primitive life could have survived such a journey. Many comets from Mars have struck the earth. Perhaps we’re all Martians!

Possibilities of life exist in other areas of the solar system as well. Enceladus, for instance, a small moon of Saturn, has a large ocean buried beneath ten kilometers or so of ice. Plumes from that ocean regularly ‘geyser-up’ from the depths of Enceladus. (Material from these geysers form one of the rings of Saturn.) Organic compounds, and more recently, phosphorus, have been discovered in these plumes, further indirect evidence of life.  Other moons, for instance, Jupiter’s Europa, contain subterranean oceans filled with who knows what? Life? We will soon find out.

Even if there is no evidence of extraterrestrial life in our solar system, we must not forget that the universe is an incredibly large place, filled with billions of stars, most of which contain planets. Although no earth-like candidate has been found  among  the five thousand exoplanets discovered so far, search for earth-like planets is just beginning. Some one has said that we have analyzed a glass of water, as it were, while the ocean of the  vast universe remains undiscovered.

Life didn't necessarily begin in a warm little pool that Darwin advocated, it just might have arisen during extreme conditions in oceanic vents. So called extremophiles today live under boiling conditions--no worry about climate change for these guys! When life originated on earth, over 3 billion years ago, conditions were far too hot to support human life. Some scientists believe that primitive life might exist  in the upper atmosphere of Venus, the surface of which is hot enough to melt lead!

There are thus at least several possibilities of life in our solar system. I wouldn’t be a bit surprised if extraterrestrial life is discovered while I’m still alive--and I've been a senior citizen for almost twenty years! Even when we lower our expectations from sublime to slime, the headlines will be splendid. And slime might be a lot more attractive than the slimy humans making headlines today. Who knows? We don’t—yet.

 

Deimos and Phobus, the moons of Mars  with which I was fascinated with when I was a kid, are almost certainly dead. But they probably contain enough precious metals to make a fortune many times over. The mining of asteroids is a distinct possibility for the next generation. This has the potential of enriching humanity to an extreme degree--if we're fair that is, and humankind hasn't been fair in the past, to say the least. Aber das ist ein weites Feld; enough for now.