11. Obliquity of the ecliptic for 20, 000 years, from Laskar ( 1986 ).12. Obliquity based on DE200, which analyzed observations from 1911 to 1979, was calculated:13. This will be associated with wild swings in the obliquity of the ecliptic as well. 14. In this figure is the obliquity , while } } is the eccentricity of the ellipse. 15. Mars changes its obliquity from about 15?to 35?in cycles of 120, 000 years. 16. Note that the obliquity varies only from 24.2?to 22.5?during this time. 17. The value 23.44?is the obliquity ( tilt ) of the Earth's axis. 18. During periods of high obliquity ( axial tilt ) the polar regions receive higher levels of sunlight. 19. When the obliquity is higher, the poles receive more sunlight, and those materials migrate away. 20. Mars has a 124, 000-year obliquity cycle compared to 41, 000 years for Earth.
