As Pluto is finally added to the University of Arizona's scale model solar system, a new study suggests how the dwarf planet's cold heart was originally broken.

In addition to the comet model, scientists also investigated a solar model, with Pluto forming from very cold ices that would have had a chemical composition that more closely matches that of the Sun.

Our model indicates that, with NH 3, the mean temperature of the mantle of Pluto is at the eutectic and its Ra ~ 10^4. The presence of NH 3 dramatically increases the vigor of convection for the two ...

Scientists integrated NASA's New Horizons discoveries with data from ESA's Rosetta mission to develop a new theory about how Pluto may have formed at the edge of our solar system.