A Planet Strikingly Similar to Earth: HD 137010 b Raises New Hopes
Sometimes the most exciting astronomical discoveries emerge from faint signals hidden in old data. That is precisely the case with HD 137010 b, a newly identified exoplanet candidate that has sparked fresh excitement among scientists. A subtle trace found in archival telescope observations suggests the presence of a world remarkably similar to Earth.
Located about 146 light-years away, this candidate planet appears to orbit a star that closely resembles our Sun, making it one of the most Earth-like discoveries to date.
Familiar Size, Orbit, and Star
Introduced in a recent study published in The Astrophysical Journal Letters, HD 137010 b is estimated to be only about 6% larger than Earth. What truly sets it apart, however, is its orbital period. The planet completes a full orbit around its star in 355 days, just ten days shorter than an Earth year.
Its host star is also Sun-like, though roughly 1,000 degrees cooler and significantly less luminous, a difference that plays a crucial role in the planet’s climate.
A Frozen World on the Edge of Habitability
Because the star emits less energy, HD 137010 b receives less than one-third of the energy Earth gets from the Sun. As a result, scientists estimate its surface temperature to be between –68 and –70 degrees Celsius, conditions more reminiscent of Mars than a habitable Earth-like world.
The planet lies on the outer edge of the habitable zone, the region where liquid water could theoretically exist. While its surface is likely frozen, researchers emphasize that habitability cannot be ruled out entirely. A dense, carbon dioxide–rich atmosphere could generate a strong greenhouse effect, potentially warming the surface enough to allow liquid water, at least temporarily.
Discovered by Citizen Scientists
Notably, the first hints of HD 137010 b did not come from a major observatory, but from volunteers participating in the Planet Hunters citizen science project. These volunteers analyzed archival data from NASA’s Kepler Space Telescope (K2 mission), which monitored the brightness of over 500,000 stars between 2009 and 2018.
In 2017, Kepler recorded a single, subtle dip in the brightness of HD 137010 lasting about 10 hours. Although multiple transits are usually required to confirm a planet, the characteristics of this signal strongly suggest a planetary origin.
Led by Alexander Venner, the research team concluded that a planet is the most plausible explanation, though HD 137010 b remains officially classified as a planet candidate.
Why HD 137010 b Matters
More than 6,000 exoplanets have been discovered so far, yet most are gas giants or extremely hot worlds orbiting close to their stars. Earth-like planets around Sun-like stars are rare and often too distant for detailed study.
HD 137010 b stands out because it is relatively close in cosmic terms and orbits a bright star, making it a promising target for future atmospheric observations. Scientists hope that next-generation telescopes could one day search its atmosphere for potential biosignatures such as oxygen or methane.
Before that can happen, additional transits must be observed to confirm its existence. Even if the planet proves to be hospitable to life, reaching it would remain far beyond our current capabilities, requiring tens or even hundreds of thousands of years of travel with today’s technology.
Still, HD 137010 b offers a tantalizing glimpse of how common — or rare — truly Earth-like worlds might be in our galaxy.
