Nearly two dozen ‘Earth-like’ planets that could be crawling with alien life have been identified by scientists.
Exoplanets are what scientists call worlds that orbit other stars (though some are ‘rogue planets’ that don’t orbit anything at all).
More than three decades after the first was discovered in 1992, the list of known exoplanets is well over 6,000.
Some are smelly, where it rains glass, or are so dark they’re barely even visible. Others are hotter than the surface of our sun and denser than gold.
So far, however, none of these planets has life. But scientists in a new paper have made the lives of alien hunters easier by compiling a list of the 45 best candidates for extraterrestrial life.
A conservative estimate, however, is just 24 worlds, or just 0.4% of known exoplanets.
Shortlist of planets for real life Project Mary
The paper, published in the Monthly Notices of the Royal Astronomical Societ last week, lists planets that are within the habitable zone of their stars.
Often called the Goldilocks zone, it’s a band of space where it’s not too cold, not too hot, so there could be liquid water on the surface.
They include the four Earth-sized planets that spin around the dim red dwarf star TRAPPIST-1, about 40 light-years away.
Proxima Centauri b, the closest known exoplanet just four light-years from Earth, is another promising rock, the researchers found.
The authors of this study say the shortlist is the best place to carry out a real Project Hail Mary, a sci-fi novel by Andy Weir that was released as a movie in 2026.
The story sees an astronaut sent out to the heavens to find an exoplanet with the key to saving lfe on Earth.
In other words, it’s the shortlist of the worlds we should send a ‘Hail Mary’ spacecraft to seek out alien life.
Experts graded each planet’s habitability odds by looking at their age, orbit, radiation exposure and how easy they are to observe from Earth.
There’s also whether they’re smack dab in the middle of the habitable zone or on the edges, like Venus and Mars are in our star system.
The team, from Cornell University, hope their findings allow space officials to know where to point their telescopes.
Making an alien world shortlist is ‘important’, says expert
Jess Lee, astronomer at London’s Royal Observatory Greenwich, who was not involved in the research, told Metro: ‘As the number of exoplanets we’ve discovered increases, the question about life existing somewhere other than the Earth remains.
‘Astronomers haven’t yet found definitive evidence for life on any exoplanet, but several current and upcoming space telescopes could help advance the search.
‘With more than 6,000 exoplanets discovered so far, narrowing down the list of planets to target is an important part of this process.
‘I’m looking forward to seeing what these newer telescopes reveal.’
Figuring out if any of these thousands of exoplanets are habitable is a tall order, given they’re millions of miles away.
One way to do so is to peek inside the planet’s atmosphere in a very elaborate way.
When light from a star shines through a planet’s atmosphere, the chemicals absorb some of the starlight’s wavelengths. This allows experts to find clues about the planet’s chemical makeup.
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