Cornell SPIF
Pluto and Charon
Pluto and Charon, its largest moon, in a ground-based telescopic image (upper left), where the Earth's atmosphere smears the light, making Charon look like a bump on the side of Pluto; in a Hubble Space Telescope (HST) Faint Object Camera (pre-costar) image, resolving the two bodies as separate disks for the first time; and an illustraton of Charon's highly inclined orbit, viewed nearly edge-on from Earth. Charon's orbit is actually very nearly circular.
The apparent ring around Pluto in the Hubble image is due to the spherical aberration of the original mirror. COSTAR (Corrective Optics Space Telescope Axial Replacement) corrected for the main mirror problem. See hubblesite.org/the_telescope/nuts_.and._bolts/optics/costar/
Image source: hubblesite.org/newscenter/archive/releases/1990/14/image/a/
Pluto and Charon
Pluto and Charon, its largest moon, in a ground-based telescopic image (upper left), where the Earth's atmosphere smears the light, making Charon look like a bump on the side of Pluto; in a Hubble Space Telescope (HST) Faint Object Camera (pre-costar) image, resolving the two bodies as separate disks for the first time; and an illustraton of Charon's highly inclined orbit, viewed nearly edge-on from Earth. Charon's orbit is actually very nearly circular.
The apparent ring around Pluto in the Hubble image is due to the spherical aberration of the original mirror. COSTAR (Corrective Optics Space Telescope Axial Replacement) corrected for the main mirror problem. See hubblesite.org/the_telescope/nuts_.and._bolts/optics/costar/
Image source: hubblesite.org/newscenter/archive/releases/1990/14/image/a/