Abstract: Calculation of the long-term evolution of the astronomical (i.e.,extra-terrestrial)radiation caused by the changes in earth-orbit parameters, obliquity of ecliptic, eccentricity and longitude of perihelion, is performed. Results show striking contrasts in seasonal radiation anomalies and geographical latitudes between the past thousand year and future three thousand year periods. It is worth noting that in the past its positive anomaly center roughly occurred over the north polar region in July and in the future it will move to 20°N in April and May, but with much weaker intensity than in the past.