Discovery Alert: ‘Super-Earth’ Swings from Super-Heated to Super-Chill
Artist’s rendering of a potentially habitable super-Earth orbiting a star called HD 20794.Illustration credit: Gabriel Pérez Díaz, SMM (IAC) The Discovery A possible “super-Earth” orbits a relatively close, Sun-like star, and could be a habitable world – but one of extreme temperature swings, from scorching heat to deep freeze. Key Facts The newly confirmed planet is the outermost of three detected so far around a star called HD 20794, just 20 light-years from Earth. Its 647-day orbit is comparable to Mars in our solar system. But this planet’s orbit is highly eccentric, stretched into an oval shape. That brings the planet close enough to the star to experience runaway heating for part of its year, then carries it far enough away to freeze any potential water on its surface. The planet has been bouncing between these extremes roughly every 300 days – perhaps for billions of years. Details The planet spends a good chunk of its...