Pluto’s surface

Pluto is normally the furthest planet from the sun, but at perehelion it is a little closer to us than Neptune is. The spectrum of light it reflected was studied and it was decided that Pluto's surface was covered with frozen methane.
 (NASA) United States 1976 Pluto’s surface

Pluto is normally the furthest planet from the sun, but at perehelion it is a little closer to us than Neptune is. The spectrum of light it reflected was studied and it was decided that Pluto's surface was covered with frozen methane.