Select Page

SETI

SETI

by William H. Benson

August 10, 2017

     One day in the 1940’s, a group of atomic scientists were discussing the possibility of intelligent life on planets outside our solar system, when one of them, Enrico Fermi, asked a blunt question, “So? Where is everybody?”

     Now known as the Fermi Paradox, what he asked was, “If there are billions of planets in the universe capable of generating and supporting life, and millions of intelligent species out there, then how come none of them have ever visited Earth, or even contacted Earth?”

     His question stumped his friends then and all those who have considered the question since then. We have no hard evidence, and no one yet has detected radio waves that originated on a distant planet. Carl Sagan’s novel “Contact,” and the 1997 film of the same name, starring Jodie Foster, considered the events that would transpire if an astronomer ever did detect a message.   

     Members of the Search for Extraterrestrial Intelligence institute look and listen for life elsewhere. Two prominent American astronomers Carl Sagan and Frank Drake founded SETI in November 1984. Based in Mountain Home, California, its members have, so far, discovered no evidence that indicates intelligent life on a planet, other than Earth.

     If they did, the announcement would astound everyone. We would admit that we are not alone.

     In 1988, astronomers discovered the first exoplanet, a planet that orbits a star different than our sun. By 2003, astronomers listed seventy exoplanets, and by last month, that number had increased to 3,621. The possibility that one exoplanet has intelligent life increases as the numbers increase.

     The physicist Stephen Hawking considers one exoplanet, Gliese 832c, most promising.

     Why did life begin here on Earth? One suggestion is that it began elsewhere and was brought here.

     Back in 1871, the British scientist Lord Kelvin suggested that “the germs of life might have been brought to the earth by some meteorite.”  Francis Crick, co-discoverer of DNA, suggested that Earth was “deliberately seeded with life by intelligent aliens,” an idea more science fiction than science.

     Still, one idea that has gathered momentum is that life originated on Mars. The theory suggests that an asteroid or a comet struck Mars in the distant past, and that ejected a Martian rock into outer space, that then struck Earth. Inside that rock were the assembled amino acids needed to start life here.

     The idea may have some merit. Of the 61,000 identified meteorites that have struck Earth, scientists have concluded that, as of March 3, 2014, 132 originated on Mars. For example, on September 28, 1969, a meteorite from Mars 4.5 billion years old, rained down upon Murchison, Victoria, in Australia, and once chemists peered into its structure, they identified seventy-four assembled amino acids.

     But then the idea begs the question, “How did life begin on Mars?”

     On November 16, 1974, at Arecibo, Puerto Rico, the astronomer Frank Drake aimed the giant radio telescope there toward M13, a cluster of about 300,000 stars in the Hercules constellation, and blasted 1,679 pulses, over 168 seconds. He chose the number 1,679, because it is a semi-prime number, the product of two prime numbers, 73 and 23.

     “Nature never uses prime numbers,” Drake says. “But mathematicians do.”

     By x’s and o’s, in binary language, on a grid, Drake transmitted “the numbers one through ten, the atomic numbers of the five most important elements, a pixelated image of a human body, a sketch of the solar system, and another sketch of the telescope.”

     For his efforts Drake received a scathing condemnation from Britain’s Royal Astronomer, Martin Ryle, who said, “any creatures out there [might be] malevolent or hungry.”

     Stephen Hawking has since urged caution also, saying that “we should be wary of sending out messages or answering back. Meeting an advanced civilization could be like the Native Americans who encountered Columbus. That didn’t turn out so well.”

     A thing to consider is how merciless Mother Nature can act. One species evolves, and another slaughters it off. The old die off, and the new live on. Darwin’s theory of “the survival of the fittest” leaves little room for pity. Aliens may not feel any compassion for planet Earth’s current rulers.

     The cartoonist Bill Watterson said, “The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us.”