Our Friendly Skies

September 04, 2007

By ROD MARTIN, Planetarium Resource Teacher and ANDY SMETZER, Tristate Astronomers

Visible Evening Planets

JUPITER is in the southwest at sunset.

Visible Morning Planets

MARS rises during the late evening and is best in the morning. VENUS climbs higher in the eastern morning sky. SATURN is low during morning twilight in the east.

Jupiter remains the best evening planet this month. It is the brightest object (except the moon) in the evening sky. Take some time to enjoy its four largest satellites through a good pair of binoculars or small telescope. They change their positions from hour to hour and night to night. Jupiter sets before midnight, shining at -2.2 magnitude in Scorpius.

The next visible planet is Mars. It is brightening to nearly 0 magnitude as it crosses the horns of Taurus into the feet of Gemini. It rises during the late evening and can be seen until the morning twilight. Look for the orange-red fairly bright "star" to the right of the bright winter stars.


Venus is now the bright "morning star." It is noticeably higher each morning this month as it rises early in September about an hour before the sun, but about three and one half hours before the sun by the end of the month. It reaches its greatest morning brilliancy on Sept. 23 at around -4.6.

Saturn is slowly rising from the morning twilight this month. It is in twilight early in September, but fairly high by month's end. Look for it on the morning of Sept. 9, when it is less than one degree from the crescent moon.

Sun and moon

The fall equinox occurs this year on Sept. 23 around 5:54 a.m. This marks an important position and time in astronomy. The fall equinox is the position of the sun when it crosses the celestial equator heading south. This is the point halfway between its highest and lowest position so daylight and nighttime are equal lengths. When the sun is above the equator, there is more daylight. When the sun passes below the equator, nighttime is longer.

We are now heading toward longer nights and shorter days. This lasts until the next equinox in March. On Sept. 1, the sun rose at 6:39 a.m. and set at 7:42 p.m., for daylight of 13 hours and 3 minutes. By Sept. 30, the sun rises at 7:06 a.m. and sets at 6:55 p.m., and has daylight of 11 hours and 49 minutes.

The sun enters the constellation Virgo the Maiden on Sept. 17 from Leo the Lion. This month, the moon was at last quarter is on Sept. 3, is new on Sept. 11, reaches first quarter on Sept. 19, and full moon on Sept. 26.

There is a partial solar eclipse on Sept. 11, but it will not be visible to us. The full moon this month is the "Harvest Moon." This is the first full moon that follows the equinox. Because of geometry, the full moon rises as the sun sets. It seems to allow extra light to finish outdoor chores.

Brish Planetarium/Tristate Astronomers

The Brish Planetarium's public programs resume Oct. 2 with "Images of the Infinite: The Hubble Space Telescope" program. This was one of the most popular ones presented by the planetarium. The Hubble Space Telescope has been in operation since its launch in 1990, dellivering unrivaled photographs and data of the wonders of the deep sky. Learn about many Hubble Space Telescope discoveries in this program. The program is held each Tuesday (except Oct. 9) promptly at 7 p.m.

Admission fees are $3 for adults, $2 for children and students, and free to senior citizens with the WCPS Gold Card. The planetarium is at the central offices of Washington County Public Schools on Commonwealth Avenue off Frederick Street in Hagerstown.

Go to to download or listen to "Skylights," the planetarium podcast. Provided by Antietam Cable and The Herald-Mail, monthly sky tours hosted by Rod Martin of the Brish Planetarium can be downloaded to help you find your way across the night sky.

For more information about the planetarium and Tristate Astronomers, visit the Web sites through and navigate to the planetarium's page. To contact the planetarium, send e-mails to

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