This is how astronomers are looking for life beyond Earth

We have been fascinated by the idea of ​​alien life for a long time. The earliest written record that presents the idea of ​​”alien” appears in the satirical work of the Assyrian writer Lucian of Samosata dated 200 AD.

In one novel, Lucian writes about a trip to the Moon and the strange world he imagines living there – everything from three-headed vultures to elephant-sized fleas.

Now, 2,000 years later, we still write stories about epic adventures beyond Earth to meet other beings (Hitchhiker’s Guide, anyone?). Stories like these entertain and inspire, and we’re forever wondering if science fiction will ever become science fact.

Not all alien life is the same

As we look for life beyond Earth, we are faced with two possibilities. We may find basic microbial life hidden somewhere in our Solar System; or we will recognize signals from intelligent life somewhere far away.

Unlike Star Wars, we are not talking far, far away in another galaxy, but about other stars nearby. It’s this second possibility that really excites me, and it should excite you too. The detection of intelligent life would fundamentally change the way we see ourselves in the universe.

For the past 80 years, programs dedicated to the search for extraterrestrial intelligence (SETI) have worked hard searching for cosmic “hellos” in the form of radio signals.

The reason we think any intelligent life would communicate via radio waves is because of the waves’ ability to travel vast distances through space, and rarely interact with the dust and gas between the stars. If there’s anything out there trying to communicate, it’s a pretty fair bet they’d do it via radio waves.

Listening to the stars

One of the most exciting searches to date is Breakthrough Listen, the largest scientific research program dedicated to the search for evidence of intelligent life beyond Earth.

This is one of many projects funded by Russian entrepreneurs Julia and Yuri Milner, with some serious dollars attached. Over a period of ten years a total of US$100 million will be invested in this effort, and they have a big task at hand.

Breakthrough Listen is currently targeting the nearest million stars in the hope of identifying any unnatural man-made radio signals. Using telescopes around the globe, from the 64-meter Murriyang Dish (Parkes) here in Australia, to the 64-antenna MeerKAT array in South Africa, the search is one of epic proportions. But he is not the only one.

Hidden in the Cascade Mountains north of San Francisco is the Allen Telescope Array, the first radio telescope built from the ground up specifically for SETI use.

Another exciting project is this unique facility, capable of searching for signals every day of the year. This project is currently upgrading the hardware and software on the original dish, including the ability to focus on several stars at the same time. This is part of the non-profit research organization, the SETI Institute.

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Space lasers

The SETI Institute is also looking for signals that would be best explained as “space lasers”.

Some astronomers hypothesize that intelligent humans could use giant lasers to communicate or even propel spacecraft. This is because we are investigating laser communication and laser-driven light transmission even here on Earth.

To search for these mysterious flashes in the night sky, we need specialist instruments in locations around the globe, which are currently being developed and deployed. This is an area of ​​research that I am excited to see progress and eagerly await the results.

At the time of writing this article, unfortunately no alien laser signals have been found yet.

Out there, somewhere

It is always interesting to think about who or what might be living out in the Universe, but there is one problem that we must overcome in order to meet or communicate with aliens. It is the speed of light.

Everything we rely on requires light to communicate through space, and it can only travel so fast. This is where my hope of finding intelligent life begins to fade. The Universe is big –Seriously big.

To put it into perspective, humans began using radio waves to communicate over great distances in 1901. That first transatlantic signal traveled only 122 light years, reaching 0.0000015% of the stars in our Milky Way.

Has your hope dwindled too? That’s okay, because here’s the great thing…we don’t have to come into the world to know that it’s out there, somewhere.

When we look at the trillions of galaxies, septillion stars, and probably many more planets just in the observable universe, it feels almost impossible that we are alone.

We cannot fully constrain the parameters we need to estimate how many other life forms might be out there, as Frank Drake famously suggested, but using our estimates and simulations the best answer right now is the thousands of possible civilizations out there. .

The Universe could even be infinite, but that’s too much for my brain to comprehend on a weekday.

Don’t forget the little aliens

So, despite listening eagerly for signs, we may not find intelligent life in our lives. But there is still hope for foreigners.

The ones that are hidden in plain sight, on the planetary bodies of our Solar System. In the coming years we will explore the moons of Jupiter and Saturn like never before, with missions looking for traces of life.

Mars will continue to be explored – eventually by humans – which may allow us to find and recover samples from new and unexplored regions.

Even if our future aliens are just tiny microbes, it would still be nice to know that we have company in this Universe.

This article from The Conversation is republished under a Creative Commons license. Read the original article.