According to scientists from Columbia University, by firing a laser beam at the precise moment when Earth crosses in front of the Sun, this can hide us from view by other stars lying at the same plane.
The Kepler space telescope uses the same method to observe exoplanets crossing in front of other stars.
Image credit Ethan Tweedie Photography, courtesy of W. M. Keck Observatory
The transit method is presently the most successful planet discovery and characterization tool at our disposal. 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.
Study co-author Alex Teachey, a graduate student at Columbia University, said to Gizmodo:
“The initial idea was about broadcasting a signal—changing the shape of a transit to encode information. But then we took it one step further, and realized you can effectively cloak your planet by modifying its transit.
If you cloaked the entire planet, they might still be able to deduce that something is going on through radial velocity measurements.
The atmospheric cloaking produces totally self consistent observations. They see a planet, but they think it’s a just another dead world floating out in space.
We could build this next week if we really wanted to. It’s totally feasible with current technology.”