Hubble Just Revealed an Extreme Planet — NASA Said It Shouldn’t Exist
NASA’s Hubble Space Telescope has spent decades uncovering planets so extreme that they challenge scientists’ expectations about how worlds can form, survive, and evolve. The terrifying object shown in the accompanying image—with what appears to be a fiery surface and an enormous mouth-like opening—is not an actual Hubble photograph of a living or monstrous planet. Hubble cannot resolve surface details like these on distant exoplanets, and such imagery should be regarded as an artistic or sensationalized representation
. The genuine discoveries, however, can be just as astonishing. One particularly puzzling world is 8 Ursae Minoris b, also known as Halla, a giant planet roughly 530 light-years from Earth. The planet orbits a red giant star that, according to standard models of stellar evolution, should previously have expanded far enough to engulf anything traveling along Halla’s present orbit. Yet observations show that the planet remains there, following a stable, nearly circular path. NASA described it as a planet that seemingly “shouldn’t be there,” although the discovery was based primarily on observations including NASA’s TESS mission rather than a new Hubble detection. NASA Science Scientists have proposed several explanations. Halla might somehow have survived a complicated stellar evolution process, or its host system may have originally contained two stars that merged, preventing either star from expanding enough to destroy the planet. Another possibility is even stranger: Halla may represent a later-generation planet that formed from material produced by the stellar merger. None of these scenarios has yet transformed the planet into anything supernatural; instead, they show how complicated planetary systems can become. Hubble itself has investigated equally extraordinary worlds. WASP-178b, located about 1,300 light-years away, is an ultra-hot Jupiter whose atmosphere reaches temperatures exceeding 3,000 degrees Fahrenheit. Hubble observations detected silicon monoxide gas on its intensely heated dayside. On the cooler nightside, scientists think this material could condense and fall through the atmosphere as rock precipitation before eventually vaporizing again. Winds may race around the planet at more than 2,000 miles per hour. NASA Science Another extreme example is WASP-12b, which circles its star from only about two million miles away. Intense gravitational forces stretch the giant planet into an elongated shape, while its swollen outer atmosphere is being stripped away by its host star. Hubble observations helped astronomers investigate this extraordinary process, with NASA describing the star as effectively “eating” the planet. NASA Science Hubble has also studied GJ 3470b, a Neptune-sized world losing its atmosphere at a dramatic rate. The discovery could help explain the mysterious shortage of Neptune-sized planets found extremely close to their stars: some may have had much of their gaseous envelopes stripped away, leaving smaller rocky worlds behind. NASA Science None of these discoveries means NASA has found a planet that literally violates the laws of physics. When astronomers say that something “shouldn’t exist,” they generally mean its presence is difficult to explain using existing models—not that nature has broken its own rules. That distinction makes these worlds scientifically valuable. Every extreme planet gives researchers another opportunity to test theories of planetary formation, atmospheric chemistry, migration and stellar evolution. The universe is not revealing impossible monsters.
It is revealing that the range of planets nature can create—and sometimes keep alive under extraordinary conditions—is far stranger than astronomers once imagined.
