Perihelion

From the Greek "near the Sun." (Peri - near, Helios - Sun). The point in a planet's orbit where it is closest to the Sun or the point that a planet reaches that position. Opposite of Aphelion. William Lilly mentioned "the apsis of Mars . . . when it shall appear in Virgo" in his famous prediction of the great 1666 London fire: "Who shall expect less than a strange catastrophe of human affairs in commonwealth, monarchy and the Kingdom of England." [double check this; how much does Mars precess per century? is this what Lilly was referring to; how accurate and well-known were Kepler's (laws) measurements at that time?]