By Matthew R. Francis , Eos/AGU. Excerpt: Our Sun is about halfway through its life, which means Earth is as well. After a star exhausts its hydrogen nuclear fuel, its diameter expands more than a hundredfold, engulfing any unlucky planets in close orbits. That day is at least 5 billion years off for our solar system, but scientists have spotted a possible preview of our world’s fate. Using data from the TESS (Transiting Exoplanet Survey Satellite) observatory , astronomers Edward Bryant of the University of Warwick and Vincent Van Eylen of University College London compared systems with stars in the main sequence of their lifetimes—fusing hydrogen, like the Sun—with post–main sequence stars closer to the end of their lifetimes, both with and without planets. “We saw that these planets are getting rarer [as stars age],” Bryant said. In other words, planets are disappearing as their host stars grow old . The comparison between planetary systems w...