anomalistic year การใช้

• A study of temperature records over the past 300 years suggests that the seasonal year is governed by the anomalistic year rather than the tropical year.
• As on Earth, there is a second form of precession : the point of perihelion in Mars's orbit changes slowly, causing the anomalistic year to differ from the sidereal year.
• On both Earth and Mars, these two precessions are in opposite directions, and therefore add, to make the precession cycle between the tropical and anomalistic years 21, 000 years on Earth and 54, 300 years on Mars.
• This suggestion is surprising because the seasons have been thought to be governed by the oscillating system driven by two inputs with slightly different frequencies : the total input of energy from the sun varies with the anomalistic year, while the distribution of this energy between the hemispheres varies with the tropical year.