Discover potentially habitable planet 146 ly away
- Astronomers reported HD 137010 b, an Earth-size exoplanet candidate 146 light-years away, after finding a single 10-hour transit in old Kepler K2 data. - The planet is about 1.06 Earth radii with an estimated 355-day orbit, but gets only 29% of Earth’s sunlight and may be colder than Mars. - It matters because the host star is bright and nearby, making this a rare Earth-like transit candidate worth serious follow-up.
A new exoplanet candidate called HD 137010 b looks exciting for a very specific reason — it is close to Earth by exoplanet standards, roughly Earth-sized, and on an almost Earth-like year. That combination is rare. But the catch is that this is not a cozy “second Earth” story yet. The object may sit near the outer edge of its star’s habitable zone, and it may also be brutally cold — possibly colder than Mars. ### What was actually found? Researchers pulled this signal out of archival data from NASA’s Kepler K2 mission, which ended years ago but still keeps giving astronomers new targets. They saw one 10-hour dip in the light from the star HD 137010 and modeled it as a planet crossing in front of the star. That candidate planet is now called HD 137010 b. ### Why is one transit a big deal? Most transiting exoplanets are confirmed because they keep crossing their star over and over. This one showed up only once. That usually means the orbit is long — in this case, probably around a year — but it also means confirmation is harder. Astronomers need to catch another transit, and if the period really is about 355 days, they do not get many chances. ### How Earth-like is it, really? In size and orbit, surprisingly Earth-like. The estimated radius is 1.06 times Earth’s, with a likely orbital period of about 355 days. The estimated distance from its star is about 0.88 AU. That puts it in the small, rocky-planet category people care about most when they talk about potentially habitable worlds. ### So why call it “cold”? Because “habitable zone” does not mean “shirtsleeve weather.” The planet is estimated to get only about 0.29 times the sunlight Earth gets. The host star is a K-dwarf — cooler and dimmer than the Sun — so even with an Earth-like orbit length, the planet may top out around minus 68 C. Basically, it may be an Earth-size world with Mars-like cold. ### Then why are astronomers still interested? Because the geometry is unusually helpful. If this candidate is real, it crosses a relatively bright, nearby star from our point of view. That matters because transiting planets let astronomers do follow-up work that non-transiting planets often cannot — timing future transits, refining the size, roughly year-long transiting candidate around a Sun-like star bright enough for substantial follow-up. ### Is it actually in the habitable zone? Maybe — but only maybe. The team estimates the planet sits near the outer edge of the habitable zone, where liquid water could exist if the atmosphere is right. That “if” is doing a lot of work. A thick greenhouse atmosphere could warm the surface. Without one, this world is probably frozen. ### What happens next? The next step is not “look for aliens.” It is much more basic — confirm the planet exists. That means catching repeat transits or using other follow-up methods to rule out false positives and tighten the orbit. Only after that does the more glamorous stuff start, like asking whether the atmosphere is thick, thin, or absent. ### Bottom line HD 137010 b matters because it is a rare kind of target — small, nearby, and on an Earth-like orbit. But right now it is still a candidate, not a confirmed habitable world. The exciting part is not that astronomers found Earth 2.0. It is that they may have found one of the best places yet to seriously check.
