Scientists Could Cloak Our Planet from Alien Civilizations Using Lasers

Thursday, 31 March 2016 - 1:10PM
Technology
Alien Life
Thursday, 31 March 2016 - 1:10PM
Scientists Could Cloak Our Planet from Alien Civilizations Using Lasers
Humans are endlessly curious about the existence and nature of intelligent alien life, and so most of the conversation surrounding extraterrestrials involves actively trying to find and/or contact them. But what if we were concerned that aliens intended to destroy us all, and wanted to hide from them? According to a new study from Columbia University astronomers David Kipping and Alex Teachey, we could use lasers as an invisibility cloak for our entire planet.


When humans are searching for potentially habitable exoplanets, we generally use the transit method, which involves detecting the slight dips in stars' brightness as planets pass them and block their light. If extraterrestrials are using the same method, then we could theoretically use some kind of light to compensate for this decrease in brightness and prevent aliens from detecting us this way.

Opening quote
"The transit method is presently the most successful planet discovery and characterization tool at our disposal," the authors wrote in their paper. "Other advanced civilizations would surely be aware of this technique and appreciate that their home planet's existence and habitability is essentially broadcast to all stars lying along their ecliptic plane. We suggest that advanced civilizations could cloak their presence, or deliberately broadcast it, through controlled laser emission."
Closing quote

For the study, the researchers calculated that we would only need to beam 30 MW lasers into space for approximately 10 hours each year while the planet is transiting the Sun. This would shield from Kepler-like broadband surveys, while making a chromatic cloak that would work at all wavelengths would require a little more power: 250 MW.

Opening quote
"You can even go further and use these tunable lasers to cloak just the biosignatures of the Earth, making our planet look like a boring dull lifeless world (that costs only a couple hundred kW of power)," Kipping told Popular Science.
Closing quote

Alternatively, if we're not too worried about an Independence Day-type situation, we could use a different version of the same method for the opposite purpose: to broadcast our presence to intelligent aliens. According to Kipping and Teachey, we could distort the transit of the lasers to an artificial shape, which would alert aliens who spotted the signal to a technologically advanced civilization.
Science
Space
Technology
Alien Life

Load Comments