Pluto
Mars
Diameterkm
2,377
6,779
Mass (Earth = 1)x
0.00
0.11
Surface Gravitym/s²
0.62
3.72
Mean Temperature°C
-230
-65
Distance from SunAU
39.48
1.52
Orbital Perioddays
90,560
687
Day Lengthhours
153.29
24.66
Known Moons
5
2
Axial Tilt°
122.53
25.19
Orbital Velocitykm/s
4.67
24.07
Quick Facts
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.
Mars
- -Olympus Mons on Mars is about 21.9 km tall -- nearly three times the height of Mount Everest.
- -A Martian day (sol) is 24 hours and 37 minutes, remarkably similar to an Earth day.
- -Mars has seasons like Earth because its axial tilt (25.19°) is very similar to Earth's (23.44°).
- -Dust storms on Mars can grow large enough to engulf the entire planet and last for months.