Asteroids go to pieces when their host star dies
Dense, hot stellar remnants often host rings of dust, gas, and asteroids. A new report helps explain how they came to be that way. (NASA/JPL-Caltech/)When astronomers look out into the galaxy, they find that many star systems fall into one of two types: alive or dead. There are plenty of healthy yellow and red stars hosting planets, not so unlike our solar system. And then there are “dead” white dwarf stars—future versions of our sun—many of which feature disks of dust, gas, and shattered debris. How does a dying star reduce the first system to the second? In part by pulverizing its asteroids with next-level sunlight, recent research suggests. When the sun someday balloons into a red giant, swallowing Mercury and Venus whole and scorching Earth will be just its first step in transforming the solar system. Because it’ll grow so much larger, our star will also flood space with...