Astro Blog

By Hannah Richter , Science.  Excerpt: In the late 2000s, planetary scientists scoured data gathered by NASA’s Cassini mission, a Saturn orbiter, about the planet’s mysterious icy moon Titan. Their exciting conclusion: The frozen world harbored an ocean sloshing around tens of kilometers beneath a thick ice shell. The ocean, hundreds of kilometers deep itself, might even be a cauldron for the “prebiotic” organic chemistry that led to life on Earth, they proposed. Now, nearly 2 decades later, researchers think they may have gotten the story all wrong. Research  presented today  here at the American Geophysical Union’s annual meeting and  published in  Nature  claims that although Titan may have once harbored a liquid ocean, today it is frozen, except for smaller melted zones deep beneath the surface. If true, the discovery will upend the long-standing assumption that Saturn’s biggest moon is a water world, like other moons in the outer Solar System,  in...

By Robin George Andrews , Science.  Excerpt: More than half of the “city killer” asteroids that might threaten Earth remain undiscovered. With an infrared eye, NASA’s NEO Surveyor aims to find them. ...a stone’s throw from NASA’s Jet Propulsion Laboratory (JPL), you’ll find the Neon Retro Arcade. Among its collection of vintage video games is the 1979 Atari classic Asteroids, in which a pixelated spaceship shoots down a barrage of space rocks to stave off fatal collisions. After long days of work at JPL, Amy Mainzer used to rack up high scores on that console. “It was a hoot,” she says. It was also apt, considering she oversees a space mission designed to spot dangerous asteroids before they crash into Earth. That mission, the Near-Earth Object (NEO) Surveyor, was conceived in the early 2000s and finally got the green light in 2022. Its components are now being built, tested, and assembled in clean rooms across the United States ahead of its planned launch in September 2027.......

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...