↑ G. K. Gilbert (February–March 1895). "Sedimentary Measurement of Cretaceous Time". The Journal of Geology. University of Chicago Press. 3 (2): 121–127. Bibcode:1895JG......3..121G. doi:10.1086/607150. JSTOR30054556. As the earth's axis slowly describes its circle on the celestial sphere the relation of the seasons to perihelion is steadily shifted. Note: It is intuitive that if equinoxes and solstices occur in shifting positions on an eccentric orbit, then these astronomical seasons must occur at shifting proximities; and as either eccentricity and tilt vary, the intensities of the effects of these shifts also vary.'l
1 2 3 4 5 6 7 Buis, Alan; Jet Propulsion Laboratory (27 February 2020). "Milankovitch (Orbital) Cycles and Their Role in Earth's Climate". climate.nasa.gov. NASA. Dicapai pada 10 May 2021. Over the last million years, it has varied between 22.1 and 24.5 degrees. ... The greater Earth's axial tilt angle, the more extreme our seasons are .... Larger tilt angles favor periods of deglaciation (the melting and retreat of glaciers and ice sheets). These effects aren't uniform globally – higher latitudes receive a larger change in total solar radiation than areas closer to the equator. ... Earth's axis is currently tilted 23.4 degrees, ... As ice cover increases, it reflects more of the Sun's energy back into space, promoting even further cooling. Note: See Axial tilt. Zero obliquity results in minimum (zero) continuous insolation at the poles and maximum continuous insolation at the equator. Any increase of obliquity (to 90 degrees) causes seasonal increase of insolation at the poles and causes decrease of insolation at the equator on any day of the year except an equinox.
↑ Barbieri, L.; Talamucci, F. (20 February 2018). "Calculation of Apsidal Precession via Perturbation Theory". Advances in Astrophysics. 4 (3). arXiv:1802.07115. doi:10.22606/adap.2019.43003.
