A Light Fantastic: Could Aliens Be Sending Us Laser Signals?

Another communication strategy that aliens might use instead of radio signals is to send brief and intense bursts of laser light across the galaxy – sort of like a signal lamp between two ships. Some space telescopes would be ideally suited to pluck out such a signal from the sky background.

Why laser beams instead of radio transmitters? A directed beam across interstellar space would be unmistakable from the stellar background and could penetrate thousands of light-years. With each pulse of energy a signal from a big enough laser optics system could appear 1 million times brighter that the transmitting planet’s parent star. The thought is that an alien society would use an agile laser-transmitter to “paint” nearby target sunlike stars with a “searchlight beam.”

A wildly ambitious, spendthrift super-civilization – a million years more technically evolved that us -- might build a moon-sized laser mirror. They would tap a fraction of their star’s energy just to power a godzillion-watt laser capable of transmitting an intergalactic beacon across millions of light-years.

Perhaps a future space telescope might intercept such a signal. (Source: blogs.discovery.com)