Neptune
Mars
Diameterkm
49,528
6,779
Mass (Earth = 1)x
17.15
0.11
Surface Gravitym/s²
11.15
3.72
Mean Temperature°C
-214
-65
Distance from SunAU
30.07
1.52
Orbital Perioddays
59,800
687
Day Lengthhours
16.11
24.66
Known Moons
16
2
Axial Tilt°
28.32
25.19
Orbital Velocitykm/s
5.43
24.07
Quick Facts
Neptune
- -Neptune has the strongest winds in the solar system, reaching speeds of up to 2,100 km/h.
- -Neptune was the first planet discovered through mathematical prediction rather than observation.
- -One year on Neptune lasts about 165 Earth years -- it has completed just one orbit since its discovery in 1846.
- -Neptune's moon Triton orbits backward (retrograde), suggesting it was captured from the Kuiper Belt.
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.