Could shooting lasers into the sky make it rain?

Researchers are working on ways to eliminate future droughts by shooting lasers into the clouds.
Written by Sarah Korones, Contributor

As the United States experiences its worst drought in over 50 years, food prices are on the rise, crops are deteriorating and cities across the heartland are experiencing water shortages. But what if all that could come to an end with rainfall on command?

Scientists don’t have a surefire way to bring on the rain just yet, but that’s not for lack of trying.

While previous efforts at inducing rainfall have involved cloud seeding, a method that injects chemicals into the clouds, research teams are increasingly turning to lasers as a less controversial, more environmentally friendly way to bring on the rain.

In a paper published last year in Nature Communications, researchers in Germany and Switzerland showed that it was possible to create water particles using lasers. While the newly formed particles were about 100 times too small to be considered actual raindrops, the experiment was a successful proof of concept in showing the ability of lasers to produce condensation.

Now, the production of even larger rain droplets is thought to be possible thanks to a rapid improvement in laser power in recent years. As a study published in the Journal of Physics D: Applied Physics points out, lasers are only becoming more powerful and precise.

The laser technique works by using a process called photodissociation in which photons break down atmospheric compounds. This produces ozone and nitrogen oxides, which causes nitric acid particles to form. The newly formed nitric acid particles subsequently bind water molecules together to create rain.

Before technical feasibility and cost-effectiveness of laser-induced rain can be determined, scientists will need to develop a more thorough understanding of the mechanisms behind the process. Future experiments will also investigate the ability to produce rain on a large scale.

In the meantime, however, drought-addled citizens of the U.S. might be wise to model the ways of the ancient Mayans.

[via Popular Science via PhysOrg]

Images: Kecko/Flickr, IOP

This post was originally published on Smartplanet.com

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