Planet Rotation Speeds

[Ed Kolis]

As for varying up the speeds, what I liked to do when I actually took the time to mod planets instead of copying them from FQM was to make the smaller planets spin faster... not sure if that's realistic or not, but it's certainly doable in the xfiles data file, given that each entry specifies a specific planet size...

[Spoo]

Typically larger planets rotate faster (at least in the Solar System).

[Fyron]

Of course, the 4 largest planets are gas giants, which have no land masses to disrupt fast-flowing winds.

[MasterChiToes]

Fyron, the link is broken on your Dev page for "FQM 5.00 Beta 13 PR 1 - 12/10/2007"

[Fyron]

Fixed.

[dmm]

Spoo said:
Typically larger planets rotate faster (at least in the Solar System).

Body ; Sidereal Period ; Synodic Period="Day"
Mercury ; 58.6467 days ; 175.940 days
Venus ; - 243.02 days ; - 116.75 days
Earth ; 23 hr 56 min 4.1 sec ; 24 hr 0 min 0 sec
Moon ; 27.322 days ; 29.53 days
Mars ; 24 hr 37 min 22.66 sec ; 24 hr 39 min 35.24 sec
Jupiter ; 9 hr 55 min 30 sec ; 9 hr 55 min 33 sec
Saturn ; 10 hr 29 min 32 sec ; 10 hr 29 min 33 sec
Uranus ; - 17 hr 14.4 min ; - 17 hr 14.4 min
Neptune ; 16 hr 6.6 min ; 16 hr 6.6 min
Pluto ; - 6 days 9 hr 17.6 min ; - 6 days 9 hr 17.0 min

[MasterChiToes]

The Terrestrial planets can be expected to turn slower due to 'tidal forces' dissipating their rotational angular momentum. If you check out the length of a day on ancient earth, it was much shorter than the Jovian planets.

In general, for a stable climate, I would agree that smaller planets better turn slower.

[Spoo]

MasterChiToes said:
The Terrestrial planets can be expected to turn slower due to 'tidal forces' dissipating their rotational angular momentum. If you check out the length of a day on ancient earth, it was much shorter than the Jovian planets.

In general, for a stable climate, I would agree that smaller planets better turn slower.

I think you would have to make a number of assumptions about the event that formed the Moon to know what Earth's original rotation rate was. Although, I agree that it must have slowed since then.

Also, tidal forces would have little effect on Mars (two very small moons), and none on Venus (no moons) - although something must have happened to Venus to make it rotate "backwards". It's generally thought that terrestrial planets with a satellite as large as the Moon are very rare. However, Mercury's rotation is very strongly determined by tidal forces from the Sun.

[Baron Munchausen]

Spoo said:

I think you would have to make a number of assumptions about the event that formed the Moon to know what Earth's original rotation rate was. Although, I agree that it must have slowed since then.

Also, tidal forces would have little effect on Mars (two very small moons), and none on Venus (no moons) - although something must have happened to Venus to make it rotate "backwards". It's generally thought that terrestrial planets with a satellite as large as the Moon are very rare. However, Mercury's rotation is very strongly determined by tidal forces from the Sun.

Venus's odd rotation (very slow retrograde) combined with the entire surface being only ~500 million years old (evenly random distribution of craters over entire planet = same age for entire surface, the number of craters gives the rough age estimate) adds up to one known cause: a huge farking impact event.

[dmm]

As a longtime reader/viewer of SF, I can tell you that your analysis is messed up. Up until the 1950s, Venus was inhabited by a technologically-advanced humanoid race consisting entirely of extremely hot babes. Then something happened, and now the place is a wasteland. Perhaps their cycles all synched up.