A Planet's Core and a Dead Star Give Us a Glimpse of Earth's Future

This artist's concept shows a debris disk surrounding a white dwarf. New research reveals the disk around white dwarf SDSS J122859.93+104032.9 harbors a small, intact planetary body that scientists think is a heavy metal piece of a destroyed planet's core. (Credit: NASA/JPL-Caltech) White dwarfs are weird objects. These dense cores of dead stars pack as much mass as the Sun into a body about the size of Earth. They're left behind when a small- to mid-sized star ends its life by ballooning into a red giant and blowing off its outer layers in a series of explosive pulses. Although these puffs of ejected material eventually create a beautiful and expansive cloud of glowing gas called a planetary nebula, the process unfortunately tends to wreak havoc on any planets residing nearby. Considering the Sun is destined to become a white dwarf in about 5 billion years, this scenario doesn't bode well ...