It's time to rethink exactly how we look for alien life
Many scientists are looking for signs of extraterrestrial life - intelligent or not - using a variety of methods, Seth Shostak, senior astronomer at the Search for Extraterrestrial Intelligence Institute (SETI), said during a call at the Future Con.
But the more our own technologies move forward, and the more people explore the rapidly evolving concept of synthetic intelligence (smart machines), the more experts suspect that intelligent extraterrestrial life could be advanced enough to stop ongoing efforts to find them, Shostak said.
However, perhaps the first question asked is why people are so fascinated by the idea of alien life - especially alien invaders, Shostak suggested. This preoccupation with an unseen extraterrestrial threat may echo from our distant past, when humans learned that survival often depends on being able to imagine and prepare for attacks from predators or enemies you couldn't see.
What we now know about the universe suggests that it is unlikely that humanity is the only form of life in it.
“Work from the past 20 years shows that there are planets around,” Shostak said. In fact, NASA announced yesterday (June 19) that the Kepler Space Telescope mission discovered 219 more exoplanets (planets orbiting stars other than our sun), bringing the total number of planets Kepler discovered to 4,034, according to Space.com. …
Most stars - 70 to 80 percent of them by some estimates - likely have planets, Shostak added. There are approximately 100 billion stars in our galaxy, which gives us about 1 trillion planets in the Milky Way galaxy. Kepler's data shows that about one in five of these planets is Earth-like - rocky and capable of supporting liquid water and possibly life, “you now have 100 billion Earth-like planets in our galaxy,” Shostak said.
And with recent research hinting that there could be as many as 2 trillion galaxies in the observable universe, this adds to the plethora of planets that may have some form of life.
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When you look at it, saying, “I don't believe in aliens,” is a bold position,”Shostak said.
There are three methods most commonly used by scientists to find someone else's life, Shostak said. The first one is simple enough - and the one most popular with science fiction writers: “Just go out and find him,” he said. This includes missions to send spacecraft to destinations such as the moon of Enneladus Saturn, where probes will sample water vapor from surface plumes to see if they contain anything of interest.
The latter method - and one practiced by Shostak and his colleagues at the SETI Institute - is eavesdropping on radio signals that an alien civilization can broadcast. Another technique is imaging distant planets with very large space telescopes capable of detecting enough detail to provide scientists with data on their atmospheres. Large telescopes such as the James Webb Space Telescope, which was due to launch in October 2018, could allow astronomers to analyze the spectrum of light surrounding a distant planet to prove atmospheric oxygen or methane, which are known to support life on Earth.
However, a complex extraterrestrial civilization could theoretically advance far beyond that, creating forms of artificial intelligence housed in machines that simply do not have the same requirements as organic life.