Jupiter reaches opposition on September 26th placing it due east as the Sun sets in the west. They are opposite each other as seen by us on Earth. This places Jupiter at its closest point to Earth since last year. Jupiter appears as the brightest object in the night sky after the Moon.
Any sky-watcher with a telescope will find magnificent features revealed viewing Jupiter with its colorful cloud-banded atmosphere. We can also see the changing positions of its 4 large Galilean Moons as they circle the giant planet in orbits ranging from 2 to 16 days.
Saturn now a month past its own opposition reaches its highest point in the southern sky by local midnight. Of course its wonderful ring system is revealed through telescopes, and its own cloudy atmosphere, similar though dimmer than Jupiter’s, may be seen. Look on September 7 and 8 as the gibbous Moon will be seen nearby.
Mars, the reddish planet, will be seen near the reddish star Aldebaran, the brightest star in Taurus the bull this month. Mars is the brighter of the the two objects, which rise in the East just before midnight. They will be seen best in the hour or two just before dawn. Mars itself will reach opposition in December when Earth and Mars will be at their closest in over 2 years.
Venus remains very bright in the eastern sky before dawn but is harder to see because its orbit is swinging it in toward the Sun, and therefore, its altitude is quite low. So look for in the first half of September before it gets too low.
Full Moon is on September 10th. The Autumnal Equinox occurs on September 22nd. Day light hours and night-time hours are about equal at this time, and the Fall season officially begins. Day length will continue to decrease for the next few months as we move toward Winter Solstice in December; just before Christmas.