Alien life on other planets is a possibility that cannot be ruled out, according to a top British astronomer.
Astronomer Royal and former president of the Royal Society Lord Martin Rees of Ludlow says scientists could not say whether aliens were ‘likely or unlikely’.
However, fans of UFO theories shouldn’t celebrate just yet as Lord Rees also says he doesn’t believe in stories of alien encounters.
Speaking on the Rosebud podcast, Lord Rees says it is unlikely that aliens exist in the way that films and media suggest.
But he says, “I think if you asked most astronomers to bet, they would bet that there are a lot of other planets on top of them.”
Astronomer Royal and former president of the Royal Society Lord Martin Rees of Ludlow (pictured) says the existence of extraterrestrial life cannot be ruled out
The 83-year-old astrophysicist is best known for his research into quasars, a type of supermassive black hole, which helped debunk the steady state theory of the universe.
However, last week the Astronomer Royal – meaning he advises the monarch on astronomical matters – said the “most exciting” topic in astronomy is the search for extraterrestrial life.
Lord Rees says the existence of aliens is ‘a fascinating question’ and that scientists ‘cannot say whether it is likely or unlikely’.
But the Yorkshire-born astronomer still doesn’t believe aliens visited Earth in the way films like ‘Close Encounters of the Third Kind’ show.
He says: ‘I get letters from people who think they have been visited by the aliens or taken by them. I don’t believe most of those claims.
“If the aliens had made a huge effort to get here, would they have encountered one or two known idiots, maybe made a corn circle and left? It seems unlikely.’
Lord Rees says he doesn’t believe aliens have visited Earth, but some form of life may exist on other planets
In our own solar system, some scientists hope to find traces of ancient life in Mars’ Jezero crater (pictured), which is believed to be a dried-up soil
Even though Lord Rees says most astronomers would be willing to bet that alien life exists on a distant world, it probably won’t be as we imagine.
He adds, “Whether they’ll have anything like aliens with eyes on stalks, so to speak, is unlikely.”
Some scientists believe that we will one day discover traces of alien life forms on Mars in our own solar system.
But as Lord Rees suggests, even the most optimistic scientists only hope to discover traces of microbial life.
Currently, NASA’s Perseverance rover is collecting samples from the Jezero Crater, an area believed to be dried up.
The rover recently identified sentiment layers in the crater’s rock layers, confirming theories that cold, arid, lifeless Mars was once warm, wet and perhaps habitable.
The Mars Sample Return mission is currently delayed due to a lack of funding, but if the samples do return, there is some hope that they could show signs of ancient life.
Lord Rees says it’s unlikely aliens would travel all the way to Earth just to make a crop circle and visit ‘one or two known gliders’
However, Lord Rees believes that signs of life can be found much further away in the atmospheres of exoplanets (planets orbiting stars outside our solar system).
Although their great distance from Earth and extreme darkness make them difficult to study, exoplanets are considered top contenders for the location of extraterrestrial life.
“The exciting thing is that with the latest telescopes it will be possible to analyze the light from these planets,” says Lord Rees.
By capturing the faint light that passes through the planet’s atmosphere, scientists can determine the chemical composition of those gases.
Lord Rees added: ‘You might find evidence of vegetation on it, oxygen in the atmosphere and things like that.
“It will be an indication that there may be a biosphere with light on it.”
Lord Rees says the best hope for discovering ancient life could be to analyze the atmospheres of exoplanets (artist’s impression pictured) to find clues about the presence of life’s chemistry.
Using this technique, astronomers have already discovered a number of planets that may already be home to extraterrestrial life.
In May, NASA discovered an Earth-like planet 40 light-years away from Earth that is in its star’s habitable zone, where liquid water can exist – a key ingredient for life.
Astronomers now plan to analyze the planet, called Gliese 12 b, to determine whether it has an Earth-like atmosphere.
However, Lord Rees adds that scientists are only just beginning to understand the chemical processes that give rise to life, which is ‘a major challenge’ for future research.
The full interview is available on the podcast Rosebud with Gyles Brandreth.