The Sky in October

Natural History, Oct, 2003 by Joe Rao

Always hasty, Mercury makes a brief appearance before dawn early this month, rising just above the due-eastern horizon. It soon disappears into the glare of the Sun and reaches superior conjunction (on the other side of the Sun as seen from the Earth) on October 25th.

Venus, shining brilliantly at magnitude -3.9, chases the Sun across the sky throughout October. As seen from midnorthern latitudes, the planet sets thirty minutes after the Sun on the 1st; by the 31st, because of both shortening days and Venus' own movements, the planet sets about an hour after our star. On the evening of the 26th it appears just to the right of a very young crescent Moon.

Mars, shining in the constellation Aquarius, crosses its highest point in the sky about three to four hours after sunset. How it has dimmed in the past few weeks! As its distance from Earth increases from 42 to 58 million miles during October, Mars fades to less than half its early-month splendor, from magnitude -2.1 to -1.2.

The king of the heavens meets the king of the jungle: Jupiter is in the constellation Leo. It rises about two-and-a-half hours before the Sun at the beginning of the month and more than four-and-a-half hours before sunrise on Halloween. On the morning of the 22nd Jupiter is well to the right of the waning crescent Moon.

Saturn, in the constellation Gemini, rises out of the northeast about five hours after sunset at the beginning of the month; by the time the hobgoblins and ghouls are out and about on the 31st it is rising less than four hours after sunset. Saturn's rings continue to be a spectacular sight, even through a small telescope. On the night of the 16th Saturn appears to hover above the Moon in the east-northeastern sky; by the 17th the Moon shifts far east of the planet.

The Moon reaches first quarter on the 2nd at 3:09 P.M. and waxes full on the 10th at 3:27 A.M. Traditionally the full Moon following the Harvest Moon is known as the Hunter's Moon. The Moon wanes to last quarter on the 18th at 8:31 A.M., and the new Moon arrives on the 25th at 8:50 A.M.

"Fall back" in much of Canada and the United States, as daylight saving time ends on Sunday, the 26th; the hour between 1 A.M. and 2 A.M. is officially repeated.

Unless otherwise noted, all times are given in Eastern Daylight Time.