See how astronomers are searching for life beyond Earth

We have long been fascinated by the idea of ​​extraterrestrial life. The earliest written reference to the idea of ​​”aliens” appears in the satirical work of the Assyrian writer Lucian of Samosata dated to 200 AD.

In one novel, Lucian writes about a trip to the Moon and the strange life he imagines living there – from three-headed vultures to fleas the size of elephants.

Now, 2,000 years later, we’re still writing stories of epic adventures beyond Earth to meet other beings (Hitchhiker’s Guide, anyone?). Stories like these entertain and inspire, and we’re forever trying to find out if science fiction will become science reality.

Not all alien life is the same

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

Unlike Star Wars, we are not talking far away in another galaxy, but rather around other nearby stars. It’s that second possibility that really excites me, and it should excite you too. A 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 tirelessly searching for cosmic “hello” 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 in space, rarely interacting with the dust and gas between stars. If something out there is trying to communicate, it’s a pretty fair bet they’d be doing so 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 several projects funded by Russian entrepreneurs Julia and Yuri Milner with some serious dollars. Over a period of ten years, a total of 100 million dollars will be invested in this effort and they have a huge big project in hand.

Breakthrough Listen is currently targeting the nearest one million stars in hopes of detecting any abnormal, extraterrestrial radio signals. Using telescopes around the world, from the 64m Murriyang Dish (Parkes) here in Australia, to the 64-antenna MeerKAT array in South Africa, the search is of epic proportions. But it’s not the only thing.

Tucked away 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.

This unique installation is another exciting project, capable of searching for signals every day of the year. This project is currently upgrading the hardware and software to the original dish, including the ability to target multiple stars simultaneously. This is part of the non-profit research organization, the SETI Institute.

Space lasers

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

Some astronomers speculate that intelligent beings might use massive lasers to communicate or even propel spacecraft. This is because even here on Earth we are researching laser communication and light laser propelled sails.

To look for these mysterious flashes in the night sky, we need special instruments in locations around the world, which are currently being developed and developed. This is an area of ​​research that I am excited to see progress on and look forward to the results.

As of this writing, unfortunately no alien laser signals have yet been found.

Out there somewhere

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

Everything we rely on to communicate through space requires light and it can only travel so fast. This is where my optimism about finding intelligent life begins to fade. The universe is big –Really large.

To put this in perspective, humans began using radio waves to communicate over long distances in 1901. This first transatlantic signal has traveled only 122 light years, reaching just 0.0000015% of the stars in our Milky Way Galaxy.

Has your optimism faded too? That’s okay, because here’s the great thing… we don’t have to find life to know it’s out there, somewhere.

When you consider the trillions of galaxies, seven million stars, and probably many more planets right in the observable Universe, it’s almost impossible to be alone.

We can’t fully narrow down the parameters we need to calculate how many other life forms might be out there, as Frank Drake suggested, but using our best estimates and simulations, the current best answer to this is tens of thousands of possible civilizations out there outside .

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

Don’t forget the tiny aliens

So despite hearing keenly for signals, we may not find intelligent life in our lifetime. But there is hope for aliens yet.

The ones hiding in plain sight, in the planetary bodies of our Solar System. In the coming decades we will explore the moons of Jupiter and Saturn like never before, with missions that will hunt for traces of basic life.

Mars will continue to be explored – eventually by humans – which could allow us to uncover and recover samples from new and unexplored areas.

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

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