Earth
Uranus
Diameterkm
12,742
50,724
Mass (Earth = 1)x
1.00
14.54
Surface Gravitym/s²
9.81
8.87
Mean Temperature°C
+15
-220
Distance from SunAU
1.00
19.19
Orbital Perioddays
365.25
30,589
Day Lengthhours
24.00
17.24
Known Moons
1
28
Axial Tilt°
23.44
97.77
Orbital Velocitykm/s
29.78
6.80
Quick Facts
Earth
- -Earth is the only planet not named after a Greek or Roman deity.
- -Earth's rotation is gradually slowing -- days are getting about 1.4 milliseconds longer per century.
- -About 71% of Earth's surface is covered by water, but 96.5% of that water is in the oceans.
- -Earth's magnetic field has flipped its polarity hundreds of times over millions of years.
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.