Scientists have found a new solar system filled with planets that look like Earth and could support life, Nasa has announced.
At least three of the seven planets represent the “holy grail for planet-hunting astronomers”, because they sit within the “temperate zone” and are the right temperature to allow alien life to flourish, the researchers have said. And they are capable of having oceans, again suggesting that life could flourish on them.
No other star system has ever been found to contain so many Earth-sized and rocky planets, of the kind thought to be necessary to contain aliens.
The researchers might soon be able to find evidence of life on the planets, they have said. British astronomer Dr Chris Copperwheat, from Liverpool John Moores University, who was part of the international team, said: “The discovery of multiple rocky planets with surface temperatures which allow for liquid water make this amazing system an exciting future target in the search for life.”
Any evidence of life is likely to be “strong, very strong or conclusive”, the scientists said. It will be done by looking for what molecules are in the atmosphere – if they were to find things like oxygen, and in the right amounts, then it would probably indicate that there was biological activity.
Co-researcher Dr Amaury Triaud, of the Institute of Astronomy in Cambridge, said: “We hope we will know if there’s life there within the next decade.”
Even if life isn’t ever found near TRAPPIST-1, it might eventually develop there. The star is relatively young – even when our own Sun has run out of fuel and our solar system is destroyed, the newly-discovered one will still be in its early infancy.
TRAPPIST-1 “burns hydrogen so slowly that it will live for another 10 trillion years – more than 700 times longer than the Universe has existed so far, which is arguably enough time for life to evolve”, wrote Ignas AG Snellen from the Leiden Observatory, in an accompanying article about the discovery.
All of the planets were found using a method called “transit photometry”. That works by watching out for when a planet passes, or transits, in front of its host star – blocking out a small amount of light, allowing us to see the planet and learn about its size.
Scientists first found the star TRAPPIST-1 in 2010, after monitoring the smallest stars close to the Sun. Since then, they have been watching out for those transits – and after seeing 34 of them clearly, they proposed that they can be attributed to the seven new planets.
They then worked to understand the size and composition of each of the worlds. That work is still continuing, but the researchers believe that the planets have large oceans, are temperate and other conditions that could make way for alien life.