What's up with mars day's?

Question

i only just found out that mars has a 24 hour day (and for those of u who don't know, earth's days are the same length). my question is, what dictates the speed that a planet rotates?

Answer 1

The length of the Mars day is actually 24h 37m. See here: http://en.wikipedia.org/wiki/Rotation_pe...

It is close to that of the earth, but not exactly equal. The length is mostly a matter of mass, at least for planets. Originally the planets rotated with approximately the same period, which than slows down over time, due to tidal friction with other planets and moons. This process is slower the bigger the planet is.

Therefore Jupiter and Saturn haven't slowed down much, Neptune's and Uranus a bit more. Mercury and Venus are in resonance with their own orbital period. The Sun's gravity is so strong that they are locked in 2:3 resonances.

The earth is an exception, presumably because it has been sped up, by a big collision, late in the formation stage. That same collision created the moon.

Answer 2

A day or "sol" on mars is 24.6597 hours per NASA.  I would think they have it right.

The best answer I could think for why this rate is "initial conditions".  The dynamics of its formation, and any close gravitational encounters with other objects in the past, would effect its rotation rate.

Answer 3

first of all, mars doesn't have a 24 hour day. it has a 26 hour day.

scientisits believe the earth rotates now because of the initial rotation as well as because of the tidal friction and the impact hypothesis.

and just so you know, i get my knowledge from a university, and not wikapedia.

Answer 4

LOL at sciencem, actually reading books to learn stuff!  What a concept!  Actually, this is only one of many things that make Mars attractive to us as a space base.  It's not all about engineering and science.  It's also necessary to keep the astronauts reasonably comfy and sane, and a base with a "day" like home would help them keep on a "normal" sleep cycle.  In other words, after the Mars colony is established, people would arrive as in "2001 A Space Odyssey", work a normal shift of maybe 8 hours, go to chow, sit and watch TV, then sleep for 7-8 hours, and then go back to work.