The Sky This Week 2004 February 27 – March 5

The Moon brightens the nighttime skies this week. Full Moon occurs on March 6th at 6:14 pm Eastern Standard Time. This Full Moon is popularly known as the Sap Moon, Crow Moon, or Lenten Moon. Look for the Moon between the bright star Aldebaran and the Pleiades star cluster on the evening of the 27th. On Leap Day night she lies a few degrees northwest of Saturn. By the week’s end you’ll find her rising in the company of bright Jupiter.

Sunday marks a special day in the Gregorian calendar as we exercise one of the rules which keep our chronological time-scale in synch with the astronomical seasons. February 29th makes its almost quadrennial appearance according to the formula promulgated by Pope Gregory XIII in 1582. Most of us just assume that Leap Years occur every 4 years; after all, the last one was in 2000. However, a slight exception to this logic means that some year that are divisible by 4 are not Leap Years, such as the years 1900 and 2100. Incurring a Leap Year every four years would accumulate an error of 11 minutes between the chronological year and the actual time it takes the Earth to go once around the Sun, and that error would amount to one day every 128 years. The Gregorian reform introduces 97 leap days in every 400 years, with a residual error of just 28 seconds. This error would accumulate one day after about 3200 years, but when you factor in variations in a number of Earth rotation and orbital parameters over the next few millennia, the error won’t manifest itself until sometime in the 8th Millennium! At any rate, enjoy this special day, and if it’s your birthday may you live to be 39!

The evening sky is now dominated by the brilliant dazzle of Venus, whose luster seems to attract even the attentions of skyscraper-bound city dwellers. Over the past several weeks I have received numerous inquiries about this bright ìstarî. During the course of an eight year cycle we average about five evening apparitions of Venus, but this one is quite special. The planet is climbing rapidly into the northern sky, and it is also well north of the Ecliptic plane. This combination will give us our best evening view of the planet since 1996, and we’ll have to wait until 2012 to see her this well-placed in our skies again.

Mars continues to drift eastward against the stars, and he is now moving into the stars of Taurus. His apparent brightness is slightly less than that of Aldebaran the Bull’s fiery eye, but the tint of the two objects is quite similar. Watch the red planet drift slowly toward the Pleiades this week.

Saturn stands high near the meridian now as evening twilight ends. He’s nearing the end of his retrograde loop for this year, grinding to a grudging halt just east of the three stars which mark the foot of one of the Gemini twins. He is still the show-stopper in the telescope, though, and he will continue to delight us as such for several more weeks.

Mighty Jupiter reaches opposition on the evening of the 4th. He’ll rise at sunset and set at sunrise. Late night skywatchers can delight at the ever-changing patterns of his bright moons ad turbulent cloud belts. I’ve already spent several late nights marveling at his fleeting features.

For information on MARS ROVER ACTIVITIES this week, click
here.

For information on BRIGHT SATELLITES passing over Washington, DC this week, click
here.

For more information eclipses, click
here.

For more information on meteor showers, click
here.

For more information on observable comets, click
here.

For pictures of Comet Hale-Bopp, click
here.

For more information on the digital planet pictures on this page, click
here.