If we are to find life that is at least as intelligent as ours, then one telltale sign will be to look for ‘technosignatures’. These are signs of technology coming from a planet which could include satellites or radio waves emitting from the celestial body. This is according to a NASA study which urges astronomers to hunt for signs of life by looking for evidence of technology.
The study also makes the extraordinary claim that alien artefacts may be on our planet, having drifted here from the likes of an ancient civilisation on Mars or Venus.
The researchers write: “‘Because the geological, paleontological, and archaeological records on Earth are so incomplete, it is even possible that the Earth itself hosts such artefacts, although, again, this idea is often conflated with unscientific popular imaginings and science fiction stories about alien visitation, and so must be approached carefully.
“If technosignatures were discovered in the solar system, it would be worth considering whether their origin might not be interstellar.
“Specifically, since the Earth is home to the only known species capable of interstellar communication and planetary travel (although both technologies remain in their early development), the Earth remains the only known planet fecund enough to promote technological life, and so it or an early, habitable Mars or Venus could even be the origin of such technology.”
The research, titled ‘Nasa and the search for technosignatures: A Report from the NASA Technosignatures Workshop’, adds that these signs could not be just limited to planets, but they could be roaming the solar system.
The study states: “Technosignatures in the solar system might come in the form of free-floating probes or structures—either passing through the solar system or in orbit around the Sun or other body—or in the form of structures or other signs of technologies on planetary surfaces.”