E.T. Friend or Foe?

A team of scientists in Australia are scanning the Universe for signals from extraterrestrial life. Professor Matthew Bailes, based at Swinburne University in Melbourne, is the lead scientist in this project funded by Russian billionaire Yuri Milner. Milner has donated $100 million and has the support of Professor Stephen Hawking. The project will use the Parkes radio telescope, one of the largest in the world at 64m in diameter and also the first to transmit images of Neil Armstrong’s first steps on the Moon in 1969.  Professor Bailes warns, however, that humans should think carefully before making contact with any extraterrestrial life that we might detect a signal from.  Their ability to send a signal tells us they must be an advanced civilisation and so possibly have the ability to threaten us. However, a bigger concern for Professor Bailes right now is knowing what kind of signal to look for.  ‘There is no manual on how to find aliens. We’ll have to imagine the sort of transmissions that an alien race might send.” Bailes hopes they might send a signal that humans would recognise, for example a sequence of prime numbers, yet he fears that by the time it reaches Earth that the team that sent it will be ‘long dead and buried’ before we have worked out a way to reply.

Artistic depiction of comets travelling towards KIC 8462852. However other theories have been postulated to explain the signal detected by Kepler, see below.

In 2015 a signal measured by the Kepler satellite sparked a new debate about extraterrestrial life, as it was identified as ‘bizarre’ by a group of researchers. What made this discovery unusual was that the star, KIC 8462852 dimmed at random times and at a dramatic rate over a period of a few years. The extent to which the star dimmed seemed too dramatic for a planet to be passing in front of the star and suggestions such as a dust cloud didn’t fit the picture. Another theory is a large cloud of comets being pulled towards the star by its gravity and partially blocking its light.  However there is also a suggestion that the dimming is caused by a large alien structure, a kind of solar panel mega-structure. Another idea put forward is that there may be the presence of a ringed, Saturn-like exoplanet?

 

Location of KIC 8462852 within the constellation of Cygnus the Swan, readily observed in the Summer time. Image credit: Stellarium/Samantha Rotherham.

 

Now that NASA’s Kepler mission is nearing its end there are two reputable key transit events for study, one from 2011 and the other that took place in 2013 over a period of a few months. Astronomers have started to look at these sources using the Allen Telescope Array, just north of San Francisco, a network of radio dishes. However, it has still to be determined what has created the signal. Seth Shostak of SETI (Search for Extra-terrestrial Intelligence) explained that people should learn from history, which ‘…suggests we’re going to find an explanation for this that doesn’t involve Klingons.’  Yet there is a possibility that this star could support life or that scientists could find the remnants of a civilization that is long extinct.

KIC 8462852 as seen in the Infrared (on the right) and in Ultraviolet (on the left

Realistically, what are the chances of finding an alien civilisation, just as advanced as or more advanced than humans? Well our Galaxy contains hundreds of billions of stars, perhaps most of them with orbiting planets.  We know some of these planets orbit in the Goldilocks zone, which is not too hot and not too cold, just right for life as we know it. However, if life exists elsewhere in the Universe will it possess any of the traits of life that scientists recognise on Earth and is this what we should be looking for?

When looking for exoplanets scientists look for the key signs of life as they are known on Earth, such as water, oxygen and carbon dioxide.  However finding oxygen certainly doesn’t guarantee there is life. For instance, scientists have now found that the interaction between titanium oxide and water could produce oxygen.

To provide a perspective, the human race has evolved in a tiny fraction of time given the solar system is only 4.6 billion years old. Only in the past hundreds of years has modern astronomy developed and then seen the vast extent of the universe and started to discover what else is actually out there.

Despite the small chances of finding extra-terrestrial life, a recent survey completed by YouGov  yielded interesting results. In it 56% of Germans, 54% of Americans and 52% of people from the United Kingdom believe that alien life exists somewhere else and could be capable of communication. However, the respondents are also wary about our reaching out to any intelligent life that might be detected elsewhere;  33% of UK residents said a digital message shouldn’t be sent compared while 46% agreed we should try and reach out. We don’t know what the alien life might look like or how it would respond.  We can only hope it doesn’t take the form of the creatures from Alien or even Mars Attack, but why are extra-terrestrials always portrayed as Earth stealing, resource taking, civilisation destroying monsters, of course with the exception of E.T and the Boov from Home?! However, for those worried about a world destroying civilisation that we might detect on KIC 8462852, it is worth noting that the star is 1500 light years away, so the light has taken that long to travel to the Earth.  It is a long way away!

Artist’s concept of your stereotypical Alien.

 

Can you get any scarier than the Xenomorph from the critically acclaimed film Alien?

 

Enrico Fermi – Italian Physicist and creator of the world’s first nuclear reactor. Born 1901, died 1954

So if there is a chance of life on another planet then why have we not come across it yet? This is known as the Fermi Paradox after physicist, Enrico Fermi who argued that, if extra-terrestrial civilisations existed, a portion of these would have developed the technology to colonise other planets. Some civilisations by now would have had enough time to disperse through the Galaxy. However there is no clear sign of any of them out there?! So this suggests that maybe there aren’t actually any other advanced civilisations in the Galaxy?  Maybe they have been destroyed by asteroid impacts, or even through through war or by degrading their environments to render them uninhabitable.

So far scientists have found 21 potentially Earth sized habitable planets outside our Solar System.  One, in particular, Kapteyn B is around 11.5 billion years old, twice the age of the Earth.  So, theoretically, it easily has had enough time for life to form and then develop interstellar travel.   Yet Kapteyn B is only 13 light years away from the Earth, and we have no evidence that it does harbour intelligent life.

It’s a strange thought to think that somewhere in the Universe there may be another life form in a galaxy, in a solar system and/or on a planet, perhaps wondering if there is intelligent life elsewhere.  With further research one day we might discover that civilisation, an event which surely would then become the most important scientific discovery to be ever made?!