Surface and Interior
of Pluto

First images of Pluto's surface

Hubble Space Telescope Images of Pluto's Surface

The surface of Pluto is resolved for the first time in these NASA Hubble Space Telescope pictures, taken with the European Space Agency's (ESA) Faint Object Camera (FOC) in 1994 (Ref). These images, which were made in blue light, show that Pluto has more large-scale contrast than any planet except Earth.

The two smaller inset pictures at the top are actual images from Hubble of opposite hemispheres of Pluto. Each square pixel (picture element) is more than 100 miles across. At this resolution, Hubble discerns roughly 12 major "regions" where the surface is either bright or dark. The larger images (bottom) are from a global map constructed through computer image processing performed on the Hubble data. The tile pattern is an artifact of the image enhancement technique (more info). Here is a Hubble Space Telescope movie of Pluto rotating.

Surface map of Pluto (Hubble Space Telescope-Faint Object Camera)

A Map of Pluto's Surface

The preceding figure (Ref) is the first image-based surface map of Pluto. This map was assembled by computer image processing software from four separate images of Pluto's disk, as described above. The map covers 85% of the planet's surface and indicates that Pluto has a dark equatorial belt and bright polar caps.

The brightness variations in this map may be due to topographic features such as basins and fresh impact craters. However, most of the surface features are likely produced by frosts that migrate across Pluto's surface with its orbital and seasonal cycles (more info).

Atmosphere and Interior

Pluto isn't large enough to retain much of an atmosphere, but it has a thin one that appears to be mostly nitrogen with some methane. We know essentially nothing about Pluto's interior at this point.