Jupiter and Saturn continue to shine brightly in the southwestern sky as darkness falls on October nights. Jupiter, the brighter of the two planets, stands 20 degrees above the southwest horizon one hour after sunset on October 1st, and will not set until 10 pm local time. However its orbit takes it lower in the sky so that it will set by 8:30 on October 31st. Jupiter remains a fine object to observe through a telescope, but only in the earlier evening.
Saturn trails Jupiter across the sky and will not set until 11:30 pm October 1st, being seen some 30 degrees to the east (or left of Jupiter). Though Saturn is much dimmer than Jupiter, it is still the brightest than all stars of Sagittarius, the constellation where it appears to be found. Telescopic views of Saturn will remain good all month.
The Moon will be seen close to Jupiter in the sky twice this month. On October 3rd, the crescent Moon will be just to the planet’s upper left; and on October 31st (one lunar month later), an even thinner crescent Moon will again be to the upper left of Jupiter. On the night of October 5th, look for the first quarter Moon just below Saturn.
Mercury and Venus will be in the southwest sky this month too, but unfortunately so low, they will be hard to spot in evening twilight. Venus being much brighter will be easier, but we will need clear lines if sight right to the horizon.
October 29th might be the best time to see both Venus and Mercury. The crescent Moon will be near both of them 30 minutes after sunset. Venus will appear to the lower right of the Moon; and Mercury will be directly below it.
Uranus reaches opposition in October 27/28, when it rises in the east as the Sun sets in the west, and is at its best for sky-watchers to find. But because Uranus is twice as far away from Earth as Saturn is, it still only reaches a magnitude(brightness) of +5.7. This means that it is just above the limit of naked eye visibility. The key to seeing it is to know precisely where to look and using binoculars to find it first.
Uranus appears among the faint stars of zodiac constellation Aries the Ram. Aries is up 2/3rds of the way to the zenith by 10 pm in the southeastern sky. If one holds a clenched fist against the sky just below Hamal the brightest star in Aries, Uranus will be at the bottom of the fist. Aries is also just below the great square of Pegasus the winged horse constellation.
Finding Uranus will be a challenge, so consult a sky map in a guide book or bring it up on line and give it a shot. Once you think you have the spot, use binoculars and you should see a greenish spot of light. Then try finding that spot with your unaided eye. If you find it know that you are looking across nearly 2 billion miles through the solar system to see Uranus. Neat!