Astronomers have identified a new candidate planet with potentially habitable conditions, located about 146 light-years from our solar system. The planet, called HD 137010 b, is about the size of Earth and has environmental characteristics similar to those of Mars. According to a study published in the scientific journal Astrophysical Journal Letters, HD 137010 b orbits a star similar to the Sun and is estimated to be about 6 percent larger than Earth. The discovery was made by an international team of scientists from Australia, the United Kingdom, the United States and Denmark, using data collected in 2017 by NASA's Kepler space telescope, as part of the extended K2 mission.
Dr. Chelsea Huang, a researcher at the University of Southern Queensland in Australia, said the planet has an orbit similar to Earth’s, with a period of about 355 days. According to estimates, there is about a 50 percent chance that HD 137010 b is located in the so-called “habitable zone” of its star, where conditions could allow liquid water to exist. A particularly interesting aspect of this discovery is the planetary system’s relative proximity to Earth. According to Huang, the nearest known planet of a similar type in the habitable zone is about four times farther away and is much fainter.
HD 137010 was discovered by the transit method, when the planet passed in front of its star and caused a slight dip in brightness. The initial signal was identified by volunteer citizen scientists as part of the Planet Hunters program. Among them was Dr. Alexander Wenner, who has been participating in the program since he was still a high school student and is now the lead author of the study. The scientists stressed that they initially treated the discovery with caution, but after extensive analysis and verification, they concluded that it is a “textbook” example of a planet passing in front of its star.
However, the star around which HD 137010 b orbits is cooler and less luminous than the Sun, which means that the planet's surface temperature could be closer to that of Mars and fall below -70 degrees Celsius. Dr. Sarah Webb, an astrophysicist at Swinburne University who was not involved in the study, described the discovery as “very exciting” but stressed that more data is needed to definitively confirm the planet’s existence. She said only one transit has been observed so far, while at least three are usually required for full confirmation. She added that while the planet could be similar to Earth, there is also the possibility that it could be a “super-snow Earth” – a large planet covered mostly in ice and with significant amounts of water in frozen form.
