Astronomers Identify Earth-Sized Exoplanet Candidate HD 137010 b Near a Sun-Like Star

A global coalition of astronomers has successfully verified a compelling new exoplanet candidate designated as HD 137010 b. This celestial body possesses a radius estimated to be approximately six percent larger than that of Earth, marking a significant find in the search for terrestrial worlds. The comprehensive details of this astronomical breakthrough were documented in The Astrophysical Journal Letters toward the end of January 2026. Situated at a distance of roughly 146 to 150 light-years from our solar system, the planet orbits a star with characteristics remarkably similar to our own Sun. This discovery was the result of a high-level collaboration involving researchers from the University of Southern Queensland (UniSQ), Harvard University, and Oxford University, showcasing the international synergy driving modern space exploration.

The journey to this discovery began nearly a decade ago when a faint transit signal was first detected in 2017 by volunteers participating in the Planet Hunters citizen science initiative. Dr. Alexander Venner, the study's lead author, originally identified the signal while he was still a high school student. Today, Dr. Venner continues his distinguished career as a postdoctoral researcher at the Max Planck Institute for Astronomy in Heidelberg, Germany. The recent verification of HD 137010 b as an Earth-sized exoplanet candidate is a major milestone for the scientific community. Confirming such small planets is notoriously difficult, as transit methods typically require multiple observations to move beyond the candidate phase and achieve official confirmation.

HD 137010 b completes a full revolution around its host star in approximately 355 days, a period nearly identical to a terrestrial year. While there is a 50 percent probability that the planet resides within its star's habitable zone, its environmental conditions likely differ significantly from Earth's. Surface temperatures are projected to be extremely low, potentially dropping below –70°C, leading researchers to describe it as a possible "super-snowball" world. The host star, HD 137010, is classified as a K-dwarf, which is inherently dimmer and cooler than the Sun. Consequently, the planet receives only about one-third of the light intensity that Earth enjoys, resulting in a frigid, Mars-like climate that presents unique challenges for potential life.

Dr. Chelsea Huang from UniSQ emphasized that the relative proximity of HD 137010 b makes it a prime candidate for future investigation using next-generation technology. Specifically, it is expected to be a key target for NASA’s upcoming Habitable Worlds Observatory. To put this discovery into perspective, the well-known habitable zone planet Kepler-186f is located four times further away and is twenty times dimmer than HD 137010. Published on January 27, 2026, the study highlights that this is the first candidate with Earth-like orbital and physical properties to transit a star bright enough to allow for such sophisticated and meaningful follow-up analysis by the global scientific community.

Despite the excitement, experts remain cautious regarding the planet's official classification. Dr. Sarah Webb of Swinburne University of Technology, who was not involved in the research, pointed out that the "gold standard" for confirming an exoplanet requires three distinct recorded transits, whereas only one has been documented for HD 137010 b so far. However, the 2017 K2 mission data used in the study demonstrated exceptional photometric precision, lending high confidence to this single transit event. The ultimate habitability of HD 137010 b will depend heavily on the presence of a substantial atmosphere, making it a critical subject for atmospheric modeling in future space missions as we seek to understand the diversity of worlds beyond our own.