the tilt - 4 Seasons, and axial spin rate.
Hello guys, I am curious if the title, the tilt, 4 seasons and such relatively fast axial spin (of 24 hours) is direct product of a great impact theory 4.5 billion years ago soon after first formation of earth? If you guys are positive, I was unable to find any sources so I would appreciate it a lot if you have anything!
Posted Oct 25, 2013, 12:10 PM UTC
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The work of Miguel and Brunini (2010) suggests that the distribution of axial tilts for terrestrial planets at formation could well be isotropic (evenly distributed in all directions), and that planetary rotation rates tend to lie between 10 and 10000 hours. Post-formation, planets can have their axial tilt and rotation rate changed by a number of things including tides and perturbations from other planets.
My guess is that we have four seasons by definition, based on having two solstices and two equinoxes. We humans could just as easily have defined three seasons, however the solstices and equinoxes are easily observable events that divide the year up pretty well. A planet will have two solstices and two equinoxes for any non-zero axial tilt. You might want to askHistorians for how the seasons got defined.