Astronomers have discovered a potentially habitable Earth-sized planet 146 light-years away, named HD 137010 b. The planet orbits a sun-like star and is estimated to be 6% larger than Earth, with an orbital period of about 355 days.
The international team, including researchers from Australia, the UK, the US and Denmark, identified the planet using data from NASA's Kepler space telescope's extended K2 mission from 2017. The planet was spotted when it briefly crossed in front of its star, causing a minute dimming event.
Dr Chelsea Huang from the University of Southern Queensland said the planet has about a 50% chance of residing in the habitable zone of its star. The star is cooler and dimmer than our Sun, meaning the planet's surface temperature could be similar to Mars, potentially below -70°C.
The faint signal was initially detected by citizen scientists, including lead author Dr Alexander Venner, who was a high school student at the time. The team's first reaction was disbelief, but after thorough checks, they confirmed it as a textbook transit signal.
The star's brightness and proximity make it an ideal target for next-generation telescopes. However, Dr Sara Webb from Swinburne University noted that only one transit has been detected, and three are typically needed for confirmation. The planet could also be a 'super snowball' – a large icy world with frozen water.
The research was published in Astrophysical Journal Letters.
