Earth-Like Planet Candidate HD 137010 b Found Orbiting Distant Star
- Astronomers have identified a planet candidate, HD 137010 b, that shares several characteristics with Earth, though it appears to be significantly colder than even the planet Mars.
- While classified as a “candidate” – meaning further observation is needed to confirm its planetary status – HD 137010 b is roughly the same size as Earth, being...
- One of the most intriguing aspects of HD 137010 b is its orbital period.
Astronomers have identified a planet candidate, HD 137010 b, that shares several characteristics with Earth, though it appears to be significantly colder than even the planet Mars. The discovery, based on re-analysis of data collected by NASA’s now-retired Kepler Space Telescope, was published on , in The Astrophysical Journal Letters.
While classified as a “candidate” – meaning further observation is needed to confirm its planetary status – HD 137010 b is roughly the same size as Earth, being approximately 6% larger. It orbits a star similar to our Sun, located about 146 light-years away. However, this star is dimmer and cooler than our own, leading scientists to believe the planet’s surface temperature is likely far below freezing, potentially colder than Mars.
Orbit and Potential Habitability
One of the most intriguing aspects of HD 137010 b is its orbital period. It completes one orbit around its star in approximately 355 days, remarkably close to Earth’s year-long orbit. This places the planet near the outer edge of its star’s “habitable zone” – the region around a star where temperatures could, theoretically, allow for liquid water to exist on a planet’s surface, given a suitable atmosphere.
However, the planet receives only about one-third the amount of heat that Earth receives from the Sun. This suggests that HD 137010 b may be a largely frozen world, potentially a “snowball planet” covered in ice or a “giant ice world.” The possibility of liquid water existing on the surface hinges on the presence of a substantial atmosphere capable of trapping enough heat to raise the temperature above freezing.
The initial detection of the planet’s signal was made by an international team of scientists led by Alexander Venner, a doctoral student in astrophysics at the University of Southern Queensland, who is now a postdoctoral researcher at the Max Planck Institute for Astronomy. The team was also assisted by volunteers from the Planet Hunters project, a citizen science initiative.
Transit Method and Data Analysis
The team employed the “transit method” to identify the planet candidate. This technique involves carefully monitoring the brightness of a star over time. When a planet passes in front of its star (from our perspective), it causes a slight dip in the star’s brightness. By measuring the amount of this dip and the time it takes for the planet to complete an orbit, astronomers can estimate the planet’s size and orbital period.
Although the transit signal was observed only once during Kepler’s second mission, the precision of the data was sufficient to provide initial insights into the planet’s characteristics. This highlights the continued value of analyzing archived data from past missions.
Future Observations Needed
Currently, HD 137010 b remains a “candidate” planet, requiring further observations to confirm its existence and fully characterize its properties. The planet’s long orbital period presents a challenge, as transit events are infrequent. This means astronomers will need patience or access to the next generation of telescopes to gather more data.
If confirmed, HD 137010 b would become a high-priority target for future space missions, such as the Transiting Exoplanet Survey Satellite (TESS) or the CHEOPS mission. These telescopes are designed to study exoplanets in greater detail, potentially revealing information about their atmospheres and compositions.
While currently beyond our reach for direct exploration, the discovery of HD 137010 b offers renewed hope in the ongoing search for potentially habitable worlds beyond our solar system. The existence of a planet with Earth-like size and orbit, even one as cold as this candidate appears to be, underscores the diversity of planetary systems and the possibility that life may exist in forms we haven’t yet imagined. The continued analysis of existing data, combined with advancements in telescope technology, will undoubtedly lead to further discoveries in the years to come.