According to a leading British astronomer, extraterrestrial life on other planets is a possibility that cannot be ruled out.
Astronomer royal and former president of the Royal Society, Lord Martin Rees of Ludlow, says scientists could not say whether extraterrestrials were “likely or unlikely”.
However, fans of UFO theories should not celebrate just yet, as Lord Rees also says he does not believe in stories of extraterrestrial encounters.
Speaking on the Rosebud podcast, Lord Rees says it is unlikely that aliens exist in the way that films and media might suggest.
However, he says, “I think if you asked most astronomers to bet, they would bet that there are a lot of other planets in 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 on quasars, a type of supermassive black hole, which helped disprove the “steady state” theory of the universe.
However, speaking last week, the Astronomer Royal – that is, he advises the monarch on astronomical matters – believes that the “most exciting” topic in astronomy is the search for extraterrestrial life.
Lord Rees says the existence of extraterrestrials is “a fascinating question” and that scientists “cannot say whether it is probable or improbable.”
But the Yorkshire-born astronomer still does not believe that extraterrestrials have visited Earth as films such as ‘Close Encounters of the Third Kind’ show.
He says: ‘I get letters from people who believe they have been visited by aliens or taken away. I don’t believe most of those statements.
‘If the aliens had made a big effort to come here, would they have run into one or two known nutters, maybe made a corn circle and left again?’ It doesn’t seem likely.’
Lord Rees says he does not believe aliens have visited Earth but that 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 thought to be the bed of a dry lake.
Similarly, although Lord Rees says that most astronomers would bet that extraterrestrial life exists on some distant world, it will probably be nothing like what we imagine.
He adds: “It’s unlikely that they have anything like aliens with eyes on stalks, so to speak.”
In our own solar system, some scientists believe that we may one day discover traces of extraterrestrial life forms on Mars.
However, 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 Jezero Crater, an area believed to be a dry lake bed.
The rover recently identified layers of sentiment in the crater’s rock layers, confirming theories that cold, arid and lifeless Mars was once warm, wet and perhaps habitable.
The Mars Sample Return mission is currently being delayed due to lack of funding, but if the samples provide any hope, they could show signs of ancient life.
Lord Rees says it is unlikely that aliens would travel to Earth just to do a crop circle and visit “one or two well-known nutcases”.
Lord Rees, however, believes that signs of life could be found much further away, in the atmospheres of exoplanets (planets orbiting stars beyond our solar system).
While their great distance from Earth and extreme darkness make them difficult to study, exoplanets are considered to be the best candidates for the location of extraterrestrial life.
“The interesting thing is that with the most modern telescopes it will be possible to analyze the light from these planets,” says Lord Rees.
By capturing the faint light passing through the planet’s atmosphere, scientists can determine the chemical composition of those gases.
Lord Rees adds: “You could find evidence of whether there is vegetation, oxygen in the atmosphere and things like that.
“It will be a clue that there may be an illuminated biosphere.”
Lord Rees says the best hope for discovering ancient life may be to analyze the atmospheres of exoplanets (pictured, artist’s impression) for clues to the presence of life’s chemistry.
Using this technique, astronomers have already discovered several planets that could harbor extraterrestrial life.
In May, NASA discovered an Earth-like planet 40 light years from Earth that lies within its star’s habitable zone where liquid water, a key ingredient for life, may exist.
Astronomers now plan to analyze the planet, called Gliese 12 b, to determine if it has an atmosphere similar to Earth’s.
However, Lord Rees adds that scientists are only beginning to understand the chemical processes that give rise to life, which presents “a great challenge” for future studies.
The full interview is available on the podcast. Rosebud with Gyles Brandreth.