The aspects given in the Almanac indicate good times to view certain planets. For the inner planets, Mercury and Venus, this is at the point of greatest elongation— the maximum separation of the planet from the Sun, either in the morning sky (rising before the Sun) or evening sky (setting after the Sun). For the outer planets, the Almanac gives dates of opposition— when a planet lies in the opposite direction from the Sun as seen from Earth. At these times the planet is passing closest to Earth, and appears at its largest and brightest. The planet is also then visible all night. Mars comes to opposition every two years two months, Jupiter every 13 months, and Saturn every year and two weeks. Not all oppositions are equally favorable, because the planets' orbits are elliptical, and their distance from Earth varies from one opposition to the next. The orbit of Mars is particularly elliptical, and its closest oppositions occur every 15 or 17 years.
Was this article helpful?