Autumn begins in the northern hemisphere at 1:02 p.m., PDT on September 22nd. Spring begins in the southern hemisphere at the same moment. Autumn will end with the winter solstice on December 21st.
Saturn, in the constellation Ophiuchus the Serpent Bearer, is the only planet visible during the early evening. Saturn appears similar to a bright golden star and is located in the south as the sky darkens after sunset. The rings of Saturn are spectacular through nearly any telescope, and they are currently tilted by their maximum amount from edge on to our view, 27 degrees, an amount that will not again be reached for nearly 15 years.
Nasa’s Cassini Spacecraft, which has been orbiting Saturn since 2004, will meet its fiery end on the 15th when it makes a planned plunge into the planet’s atmosphere. This controlled ending, before the spacecraft runs out of fuel, will prevent Cassini from hitting and possibly contaminating any of Saturn’s moons, which can’t be ruled out as potential habitats for life.
On the 12th, the moon will block the light of, or occult, the bright orange star Aldebaran in Taurus the Bull. Use binoculars to see the star suddenly wink out of view as it slips behind the moon’s dark limb at 4:34 a.m.
On the 16th through the 18th, the Moon closes in on the early morning planets Venus, Mercury and Mars. Located above the eastern horizon at dawn, Venus is the brightest of these objects, followed by Mercury and Mars.
Additionally, the bright star Regulus, in Leo the Lion, is close to Mercury on the 16th and to Venus on the 19th and 20th. Mars and Mercury appear very close to each other on the 16th, and Venus is paired closely with Mars on the 18th. These shifting groupings of planets against the distant stars allow you to observe the motion of the planets as they revolve around the sun.