- Synodic: a synodic cycle measures successive returns of a planet to its conjunction with the Sun, as seen from Earth. From the Greek sınodos 'meeting'.
See also: apogee | perigee
The diagram shows the synodic cycle of Venus, as seen from Earth. The trail that has been picked out shows the geometrical relationship that Venus makes with the Earth, beginning with the superior conjunction of 11th January 2010 (at 22 Capricorn) and ending with the completion of the cycle on 16th August 2011, (the next superior conjunction at 23 Leo). As one cycle leads to another, Venus will trace out an almost perfect pentagram over five cycles, which will take eight years to complete.
Text and diagram © Deborah Houlding, 16/02/10