The White Dwarf that Shattered Asteroids and Earths

Illustration for article titled The White Dwarf that Shattered Asteroids and Earths

Rings of debris from shattered asteroids and Earth-like planets orbit many white dwarf stars - their remains testimony to how common Earth-like bodies really are in space.


A group of scientists from California using the Spitzer Space Telescope have examined the debris rings around six different white dwarfs, one of which is depicted above in this artist's rendering. What they found was that a lot of these shattered rocks were low in carbon but high in other minerals common to rocky planets in our solar system. Planets in our system are also low in carbon.

The researchers announced their findings at this week's meeting of the American Astronomical Society in Long Beach, CA. According to Centauri Dreams:

When a star like our Sun reaches the end of its life and becomes a red giant, it consumes any inner planets and perturbs the orbits of the surviving planets and asteroids. A white dwarf is the end result of this stellar expansion and subsequent collapse. Objects wrenched out of their former orbits should, like the asteroids in question, occasionally drift close enough to the star to be pulled apart by its gravity. Such a star, showing the excess infrared signature of a circumstellar disk that is likely caused by the tidal disruption of asteroids, is called a ‘polluted’ white dwarf.

And that's what we're seeing here.

SOURCE: Astronomical Journal.
Image via NASA/JPL-Caltech.


we really need a reasonable if not solid definition of "Earth-like"

to me 'rocky inner planet' doesn't cut it...