The sky changes in predictable but surprising ways. Lately I have been hearing a lot of visitors to Frosty Drew Observatory asking about the return of Jupiter and Saturn this fall. They were magnificent last fall, but this year they won't really return until well into winter. In the year since these two giants were in our sky they have moved to the east.

Jupiter's rotation about the Sun causes it to rise two hours later than last year. This moves Jupiter from the constellation Taurus [the Bull] in between the two Gemini [the twins brothers Castor and Pollux]. Due primarily to the Earth's motion, it will seem as if Jupiter is shuttling between the two brothers throughout the fall.

Saturn's rotation has moved it almost three quarters of an hour later than last year, but Saturn still remains in the same constellation of Taurus [the Bull]. However instead of being in the leading portion of Taurus (near the Pleiades), Saturn will be the trailing part of the constellation, placing Saturn between the Bull's horns. The same shuttling motion caused by Earth will seem to cause Saturn to bounce between the left and right horns.

As if to make up for the later arrival this year of the giant planets, Mars will move quickly towards its high point in the due south in July and remain there shortly after sunset through the remainder of the year. Mars has already been passed by the Earth and it will slowly diminish in size. This is quite a difference from last year when Mars never was in the evening sky.

The outer three planets, Uranus, Neptune and Pluto move very slowly. Unlike the inner six planets, these remote members of the solar system move to the east at a barely perceptible pace. They seem almost fixed in place. Uranus will be at its high point in the south just as Saturn rises. Neptune will reach its high point when Deneb (the tail of Cygnus the Swan) is directly overhead. Pluto remains in Ophiuchus were it has spent most of the last three years. Only Uranus is easily spotted in binoculars. Neptune is hard to locate without a sizable telescope. Pluto is best left to a large telescope with precise pointing capabilities.

Venus left the evening sky in March becoming a morning star for the rest of the year. Early astronomers were confused by Venus' long stays in the evening or the morning sky. They did not recognize that this was a single planet. They called the bright planet in the evening sky Phosphorus and the bright morning planet Hesperus.

Mercury, as always dart in and out rapidly changing from a morning to an evening apparition and back. It will be in the morning sky until the end of July reaching its greatest brightness during the third week of July. It will make an appearance in the evening sky during August and September, but it will stay near the Sun making it hard to see. It flashes back into the morning sky in October and November. Near the end of December it will climb out of the Sun's glare in the evening sky.

Meteor "showers" will decorate the summer and fall skies. These showers are often greatly over hyped causing people to expect something like a Independence Day Firework display. Once in a long while at some particular point on the Earth this will happen. However most of time these showers amount to several dozen small strikes and one or two large fireballs throughout an entire evening. Look for:

Jul 27-28 near 2:00 AM Delta Aquarids
Aug 11-12 near 3:30 AM Perseids
Oct 19-20 near 4:00 AM Orionids
Nov 4-5 near 0:30 AM Taurids (Southern)
Nov 11-12 near 0:30 AM Taurids (Northern)
Nov 17-19 near 5:00 AM Leonids
Dec 11-12 near 2:00 AM Geminids

As the commercials say, your mileage may vary. Good hunting.

Author:

Leslie Coleman

Entry Date:

Jul 1, 2001

Published Under:

Leslie Coleman's Columns