July 1997

by Steve Stefanik

All eight of the other planets of our solar system will be visible before midnight in the July night sky. Starting at sunset, the planets Mercury and Venus can be seen hovering above the northwestern horizon. Venus is a cinch to spot as a brilliant sparkling -3.9 magnitude star. Mercury is considerably more difficult to locate because it is at a dimmer -0.4 magnitude. Look for the pair of planets near the brightest star Regulus in the constellation Leo. Mercury will be more orange in color and lower to the right of Venus.

Mars is the next planet to spot higher in the western sky among the stars of the constellation Virgo. Look for the bright +0.7 magnitude red-orange orb near the bright blue first magnitude star Spica. Don’t confuse it with the brighter first magnitude yellow-orange star Arcturus in the nearby constellation of Bootes further to the east or the red-orange star Antares in the constellation Scorpio further to the south.

Just north of Scorpio lies the constellation Ophiuchus the serpent bearer. Although invisible to the naked eye, Pluto the dimmest and most distant of the planets can be found with the aid of a telescope and a camera over successive nights moving slowly against the background of stars.

The planets Uranus and Neptune are the next to rise and can be found with binoculars along the Sagittarius-Capricornus border. Uranus is the closer and brighter of the pair at magnitude +5.7 when it reaches opposition on the 21st of this month. Look for the pale green planet south of Capricorn. Neptune is somewhat more difficult to locate. It will only reach +7.8 magnitude when it arrives at oppositon on the 29th. It is considerably bluer than Uranus and closer to the constellation Sagittarius.

The next planet to rise is the gas giant Jupiter. You shouldn’t have difficulty locating this brilliant -2.8 magnitude 48 arc second sphere on the eastern side of Capricorn. It outshines everything but Venus and the moon. Look for it near a one day past full moon on the night of the 21st in the east.

The last of the planets to rise is of course Saturn. Look for the ringed planet due east shortly before midnight among the stars of Pisces. It reaches +0.5 magnitude by the end of the month. A waning gibbous moon passes it on the night of the 25th.