Other viewers might be found in TRAPPIST-1, a planetary system 39 light-years away that includes three exoplanets that scientists think could be habitable, according to a statement from MIT about Clark's study.
And if the Land was used as a beacon to the aliens using a laser to super-powerful? The signal should be easy to detect from as far away as 20,000 light years.
"This would be a challenging project but not an impossible one", he stated.
- The infrared signal produced would be more than 10 times the infrared emissions from the sun. "I don't know if intelligent creatures around the sun would be their first guess, but it would certainly attract further attention". According to his calculations, a 2-megawatt laser paired with a 30-meter telescope would do the trick, as would a 1-megawatt laser paired with a 45-meter telescope.
"The kinds of lasers and telescopes that are being built today can produce a detectable signal, so that an astronomer could take one look at our star and immediately see something unusual about its spectrum", Clark said. While the Earth has been sending signals like radio waves into space for over a century, like those famously seen in the opening of Contact, it's possible that solar entities like the sun and exoplanets beyond the solar system have been interfering with signals, making it harder for potential aliens to touch base. As a result, you will create a beam of infrared light that will be strong enough to stand out on the background of solar energy. More massive telescopes are being developed, though, with construction underway for both the 24-meter Giant Magellan Telescope and the 40-meter European Extremely Large Telescope. While Earth now has the technology to create the beacon, the beam would produce 800 watts of power per square meter that would damage a person's vision.
Such a powerful beam could also present a few safety and technology problems for any biological or digital eyes that happen to look directly at it. Clark says the beam wouldn't be visible but could still conceivably damage people's vision inadvertently and could scramble cameras aboard orbiting spacecraft that pass through it. A safer location than Earth would be on the far side of the moon. There is legitimate concern that Earth's resources could be too tempting to resist, and that we might invite our own extinction by luring extraterrestrials to our neck of the woods.
Clark says that if the tables were turned, we would be able to detect a signal sent from nearby stars but only if our telescopes were pointed directly towards the source, which would take an enormous amount of luck.
The study suggests the light from a laser could spark interest from extraterrestrials- if they exist.