Two Columbia University astronomers, Professor David Kipping and graduate student Alex Teachey, suggest humanity could use lasers to conceal the Earth from searches by advanced extraterrestrial civilisations. David comments: "There is an ongoing debate as to whether we should advertise ourselves or hide from advanced civilisations potentially living on planets elsewhere in the Galaxy. Our work offers humanity a choice, at least for transit events, and we should think about what we want to do." Several prominent scientists, including Stephen Hawking, have cautioned against humanity broadcasting our presence to intelligent life on other planets.

The two authors of the new study suggest that controlled laser emission could be used to mask transits - the dips in light when a planet moves directly in front of the star it orbits – which is the same technique we use to search for exoplanets.  Given that humanity is already capable of modifying transit signals, it may just be that aliens have had the same thought. The two scientists propose that the Search for Extraterrestrial Intelligence (SETI), which mostly currently looks for alien radio signals, could be broadened to search for artificial transits.

Reference: 

• "A Cloaking Device for Transiting Planets", David M. Kipping and Alex Teachey, Monthly Notices of the Royal Astronomical Society, Oxford University Press - March 30, 2016 - DOI: 10.1093/mnras/stw672 - OPEN ACCESS

For more on this story, go to The Watchers website: http://thewatchers.adorraeli.com/2016/04/01/astronomers-suggest-laser-cloaking-device-to-hide-earth-from-advanced-extraterrestrials/

Credit Source for Picture at Top of Page
Featured image: A 22W laser used for adaptive optics on the Very Large Telescope in Chile. A suite of similar lasers could be used to alter the shape of a planet's transit for the purpose of broadcasting or cloaking the planet. Credit: ESO / G. Hüdepohl
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