With dozens of extrasolar planets already identified, finding extraterrestrial life seems inevitable. What's our strategy?
I devoured science fiction as a kid, especially by the hardcore science guys like Larry Niven and David Brin (Lucifer's Hammer and Startide Rising remain two of my favorite books). I particularly liked stories that explored the ramifications of planets with entirely different conditions, such as the way a low-gravity environment might foster the evolution of tall, thin creatures too fragile for Earth (a shout out here to C.S. Lewis’ little-known science fiction outing, Out of the Silent Planet, tipped my way by Automotive Designline editor Rick deMeis). Little surprise, then, that the recent spate of extra-solar planet discoveries has me wondering about how we’ll react when, as seems inevitable, we discover a planet that displays the right set of conditions to support carbon-based life.
The telescope was invented in the 1600s but it wasn’t until the mid 1990s that astronomers began to acquire serious evidence of exoplanets. Fast forward to the present, when detection of such planets has become routine, courtesy of initiatives like the European Southern Observatory’s (ESO’s) High Accuracy Radial Velocity Planet Searcher (HARPS) program and NASA’s Kepler Mission.
The ESO recently announced the discovery of 50 new exoplanets, 16 of which are classed as super-Earths. Of this collection, one skirts the so-called habitable zone, designated as the range that would permit the existence of liquid water, essential to carbon-based life. Mounted on the LaSilla Observatory’s 3.6-m telescope, the HARPS spectrograph detects Doppler shifts in a star’s spectrum introduced when an orbiting planet perturbs the star’s position relative to Earth.
Meanwhile, the 0.95-m orbital Kepler telescope has identified 1235 candidate planets, nearly 20 of which are confirmed. The 95 mpix focal plane array on the Kepler tracks variations in a star’s emission caused by the transit of a planet across its face.
For years, common wisdom held that detecting planets against a stellar background was unlikely, at best. Today, we can not only find planets, we can determine characteristics like temperature, diameter, and atmospheric composition. So if we find the right set of conditions for carbon-based life, what type of information do we look for next and how do we get it? What kind of instruments do we need to do it?
How about communications? Radio telescopes affiliated with the Search for Extraterrestrial Intelligence are searching over the the 1- to 11-GHz range for sinusoidal waveforms. What types of signal processing techniques might detect a highly degraded radio signal? And are mathematics truly universal if you’re a chlorine-breathing gas ball?
What do we do if we detect a signal? Okay, now ride with me here. I know that Proxima Centauri lies a good 4.2 ly away—tens of thousands of years travel by by even the means. (Wormholes? That might take tens of thousands of years to develop, itself.) But what types of propulsion systems could we pursue to speed things up? The folks at Project Icarus are working to develop a probe concept for travel to other planets. There are some pretty sharp engineering minds at this site—what would you do?
Let's take it one step further. If we weren’t stuck in a backwater of the universe, if the distances were cut by three orders of magnitude, what should we do then? Voyager 2 launched in 1977 and technology has moved on. How should we alter the payload? What kinds of instruments should the probe sport? What should the message be?
And what do you consider the best science fiction book ever?
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...What kinds of instruments should the probe sport?
We are a species driven by what we can see. So, nothing more than a glorified camera is needed. The technical challenge will be a signal of sufficient strength to travel X light years before reaching Earth, but I suppose if Interstellar travel can be made 1000x faster, then there should be no problem using the target star as a source of energy to amplify the return signal.
Having to wait maybe 10-50 years for a signal is reasonable, given the travel time of the New Horizons mission to Pluto, a far less interesting mission, sent to analyze two chunks of ice that happen to be on the fringe of our solar system.
I know the distances involved are absurd, but I also know human nature. If, or rather when, we find life on another planet, the life on this planet won't be able to ignore it. Finding a habitable planet would spark interest and finding actual life would be front page news, but if that life proved to be intelligent? We wouldn't be able to rest until we established contact or at least knew more about the beings involved. Shoot, Project Icarus is already working on the problem, even with no life involved. The distances are completely out of scale with our capabilities and lifespans -- but the science and technology community would be expected to come up with the answers. How would you solve the problem?