Uranus
Pluto
Diameterkm
50,724
2,377
Mass (Earth = 1)x
14.54
0.00
Surface Gravitym/s²
8.87
0.62
Mean Temperature°C
-220
-230
Distance from SunAU
19.19
39.48
Orbital Perioddays
30,589
90,560
Day Lengthhours
17.24
153.29
Known Moons
28
5
Axial Tilt°
97.77
122.53
Orbital Velocitykm/s
6.80
4.67
Quick Facts
Uranus
- -Uranus rotates on its side with an axial tilt of 97.77°, likely caused by a massive ancient collision.
- -Uranus was the first planet discovered with a telescope, found by William Herschel in 1781.
- -All 28 of Uranus's moons are named after characters from Shakespeare and Alexander Pope.
- -Uranus's blue-green color comes from methane in its atmosphere absorbing red light.
Pluto
- -Pluto was reclassified from planet to dwarf planet in 2006 by the International Astronomical Union.
- -Pluto's largest moon Charon is so large (half Pluto's diameter) that they orbit a point between them, forming a binary system.
- -Pluto's famous heart-shaped feature, Sputnik Planitia, is a vast plain of nitrogen ice over 1,000 km across.
- -One year on Pluto takes 248 Earth years -- it hasn't completed a single orbit since its discovery in 1930.