Is there life out there in space?

It’s the age-old question, with the unimaginable depths of other solar systems, other galaxies, other life hiding in distant corners of outer space inspiring scientists, astronomers, novelists and filmmakers for centuries.

And with experts admitting that it is highly unlikely that our planet is the only one bearing intelligent life forms, the search for alien life goes on.

But did you consider that while we’re looking for them, they might be looking for us too?

And perhaps one day we’ll pick up their transmissions and realise, once and for all, that we’re not alone in space.

In a recent paper published in the Astronomical Journal, researchers from Penn State documented one such way that we might, one day, receive these transmissions.

Using the Allen Telescope Array (ATA) the researchers used the modified radio antennae based in the Cascade Mountains at Hat Creek Observatory to scan space for narrowband signals. These specific signals were determined as possible ways in which we could pick up technology developed and run by aliens from other planets.

But these signals would only be able to be picked up, at least at present technical capacities, during planet-planet occultations (PPOs), the period in which a planet moves in front of the Earth. At this point, we would be able to pick up radio signals from the other planet – whether they were intended for us or not.

This is the same way in which we communicate with technology we have placed on other planets, for example the Mars rovers.

In their research, the scientists scanned the TRAPPIST-1 star system. Located about 41 light years from Earth, this is considered the closest system where alien life could exist since, of the seven rocky planets that orbit the star, some are in the ‘Goldilocks Zone’, meaning that the atmospheric and terrestrial conditions could allow for the presence of liquid water and, therefore, life.

As Penn State’s Nick Tusay explained in a statement, the proximity and conditions of TRAPPIST-1 made it perfect for testing the equipment and scanning for life:

“The TRAPPIST-1 system is relatively close to Earth, and we have detailed information about the orbit of its planets, making it an excellent natural laboratory to test these techniques. The methods and algorithms that we developed for this project can eventually be applied to other star systems and increase our chances of finding regular communications among planets beyond our solar system, if they exist.”

While the equipment did detail 11,000 potential narrowband signals (from millions that it detected), only 2,264 of those were during PPO windows.

Of those signals, it was ultimately determined that all had human origins.

However, the lack of signals detected from TRAPPIST-1 has not deterred the team from their search for life in space, as Tusay continued:

“Most searches assume a powerful signal, like a beacon intended to reach distant planets, because our receivers have a sensitivity limit to a minimum transmitter power beyond anything we unintentionally send out. But, with better equipment, like the upcoming Square Kilometer Array, we might soon be able to detect signals from an alien civilization communicating with its spacecraft.”

By continuing to adapt their equipment along with the development of new technology, the researchers hope that one day, their search will be fruitful and alien life will be confirmed.

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