Scientists believe they will be able spot of life on ‘thousands’ of planets within the next 20 years

Scientists looking for evidence of extraterrestrial life believe they will discover telltale signs on “thousands” of planets within 20 years.

Increasingly powerful telescopes will be able to probe the atmospheres of planets hundreds of light years away for evidence that we are not alone in the universe.

And if experts find enough clues, they might even hypothesize how alien life compares to species found on Earth.

Cambridge scientist Emily Mitchell said she believed life was probably “quite common” in the cosmos, and hopes to find evidence. The evolutionary zoologist investigates whether it was a fluke that single-celled life developed on Earth and evolved into complex animals over billions of years, or whether this process was repeated throughout the universe.

Signs of life on a planet are called “biosignatures,” and Dr. Mitchell said, “We only have one biosignature here on Earth. But when we have thousands of biosignatures in 10 or 20 years, as my optimistic colleagues suggest, we can begin to address (the question of whether we are alone in the cosmos).

“There’s tremendous potential that if we have enough biosignatures, we can calculate the numbers and try to figure out how we’re doing compared to life on other planets.”

In 2021, NASA launched the James Webb Space Telescope, which allows scientists to see further and in greater detail than the 33-year-old Hubble telescope.

It can capture starlight passing through the atmosphere of a distant planet and analyze it for signs of chemicals generated by living organisms. The telescope has already provided a detailed view of the “sky” on a planet called Wasp-39B, about 700 light-years away.

NASA is planning “aggressive technology development” for a possible future project called the Habitable Worlds Observatory, which will specifically examine the skies of Earth-like “exoplanets” for signs that they could support life.

Dr. Mitchell said that if oxygen, water, and methane were all found in one atmosphere, “you could say, ‘Yeah, that’s definitely life.'” Biosignatures could reveal whether the origin of life on Earth is just a happy coincidence or part of the fundamental nature of the universe.’

So far, more than 5,300 exoplanets – the name given to planets outside our solar system – have been discovered, including one in another star system. Scientists say there are probably trillions in the Milky Way alone.

Dr. Mitchell shared her thoughts yesterday at the annual meeting of the American Association for the Advancement of Science in Washington. Also speaking at the event was Swiss astronomer Didier Queloz, a Cambridge fellow who won a Nobel Prize for discovering the first exoplanet in the 1990s.

NASA is planning “aggressive technology development” for a potential future project called the Habitable Worlds Observatory, which will specifically examine the skies of Earth-like “exoplanets” for signs they could support life

He said it would be “foolish to predict” when extraterrestrial life might be discovered, adding: “Maybe in a few years someone will detect an atmosphere similar to Earth with the James Webb telescope.” Or maybe we’ll find out that most planets don’t have atmospheres and realize we’re damned lucky on Earth.’

But he also said that if we found signs of extraterrestrial life, it could be very different from the carbon-based forms we have on Earth, because there could be more than one “chemical scenario leading to life.”

Cambridge is collaborating with other universities on the research through a consortium called The Origins Federation. The group warned that “humanity has a long way to go before we fully understand the fundamentals of what life is and how it originates.” Prof Queloz, 57, added: ‘We are working on it. Hopefully I’ll see something important in my lifetime.’