This is an image of the surface of Pluto.
Image from: NASA

Pluto's Surface and Interior

Data from 1999 suggests that the surface of Pluto is made of several components; it has both an icy component and another component which may be rocky. The icy component is primarily made of frozen nitrogen, but likely contains smaller amounts of frozen carbon monoxide and methane. Pluto is so far away that is it very hard to see the planet, so we can't yet tell how much of the surface is covered with ice, and how much is covered with something which is not ice (the possibly rocky component). But the surface is good at reflecting light, which suggests that it is mostly made of the icy component - and that means Pluto's surface is mostly composed of nitrogen.

The surface of Pluto shows remarkable dark markings reminiscent of Saturn's moon Iapetus. Winds of Pluto's atmosphere may contribute to sweeping the ices away from some regions and leaving dark markings, as can be seen in this image.

The interior of Pluto is probably similar to that of major icy moons such as Ganymede. (Pluto is smaller than Ganymede).

The evolution of the binary planet Pluto and Charon may be like only one other planet in the solar system, that of the Earth and its moon.

Last modified January 19, 2001 by Jennifer Bergman.

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