Mars
Pluto
Diameterkm
6,779
2,377
Mass (Earth = 1)x
0.11
0.00
Surface Gravitym/s²
3.72
0.62
Mean Temperature°C
-65
-230
Distance from SunAU
1.52
39.48
Orbital Perioddays
687
90,560
Day Lengthhours
24.66
153.29
Known Moons
2
5
Axial Tilt°
25.19
122.53
Orbital Velocitykm/s
24.07
4.67
Quick Facts
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.
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.