Hairspray: A sign of intelligent life
The greatest and most perplexing questions in history, with profound and far-reaching consequences when answered, is the simple query “are we alone in the universe?” A group of scientists at the Blue Marble Space Institute of Science, a nonprofit research institution, are now suggesting that perhaps the humble hairspray may give us the answer.
In the past century, the development of chlorofluorocarbons (CFCs) have left an indelible mark on Earth’s atmosphere. Used in a slew of applications from aerosol sprays to refrigerator coolants, CFCs were once a household product. Compared to the chemicals they replaced, such as ammonia and chloromethane, CFCs were relatively non-toxic and completely inert in normal conditions. The downside, though, was that once CFCs found their way into the atmosphere, they acted as long-lasting greenhouse gases and depleted the ozone layer.
A subset of the search for extraterrestrial life is the search of extraterrestrial intelligence (SETI), which focuses on finding intelligent life with advanced technology. Currently, SETI projects center on searching for high-power, narrow-band radio transmissions that technologically advanced civilizations might give off. Aside from the “WOW!” signal of dubious origins in 1977, such searches have so far been futile.
Looking for transmissions, may not be an effective method for finding life. Transmitting a directed signal across interstellar space is extremely energy-costly, so a civilization would naturally limit its output. To improve the signal quality, the aliens would focus energy into a very thin beam across a very narrow range of frequencies, and transmit the signal in a short, but high-power burst.
For us to detect such a signal, we would have to be in the beam, which is highly unlikely given all the possible directions in which the aliens could have sent the signal. Then, we would have to be listening at the right time on the right frequency.
CFCs, on the other hand, might be detectable at any time. Many planets are discovered via the transit method in which the minute dimming of the parent star is measured when the planet passes between us and the star. During the transit, sensitive spectroscopes can measure the atmospheric content of the planet. Because CFCs do not occur naturally, any sign of CFCs would be positively indicative of life. Unlike radio transmissions, CFCs and their effects are persistent, and thus could be detected at any time.
The scientists are hedging that alien civilizations may have followed the same route as we have during industrialization, picking CFCs because they are chemically favorable. Or, if some advanced civilization decided to terraform a planet to make it habitable, the aliens may have released CFCs to heat up the planet’s atmosphere.
Regardless of why aliens may have used CFCs, it would be a sure sign that there are other life forms out there. The researchers are now running simulations to see if already-available data could be reanalyzed for the signatures of CFCs. If so, signs of life may have been hiding in plain sight, just waiting to be discovered.