The Sky This Week 12-18 March 2003
The Moon brightens the overnight sky this week. The Full Sap Moon occurs on the 18th at 5:35 am Eastern Standard Time. Look for Luna close to bright Jupiter on the evening of the 14th. On the 15th, she lies a few degrees west of the bright star Regulus in Leo, the Lion. The next night finds her east of the star. On the evening of the 19th she is in the company of Spica, an icy-blue tinted star that is actually a harbinger of spring.
The Vernal Equinox is fast approaching. It occurs on the evening of the 20th at 8:00 pm EST. I think it’s safe to say that we’ve all been anticipating its arrival, and as we watch the annual spurt of new growth and regeneration, it’s also time to look for changes in the sky. This is the time of year when the rate of change of sunrise and sunset times is greatest, and each day gains on average about 3 minutes of daylight. We see this best in the evening as we watch the rapid descent of winter’s constellations in the west. Orion and his cohorts will seem to plunge from sight over the course of the next month or so. They will be replaced by a number of somewhat dimmer star patterns like Leo and Ursa Major, which have familiar shapes but lack the brilliant fires of the winter sky.
Saturn follows the winter stars to their evening rest, but he’s located high enough on the Ecliptic to enable him to longer than some of his brilliant neighbors. The ringed planet is still excellently placed for an early evening telescopic view, but he’s now past the meridian as the Sun sets. This only leaves about two hours of observing time in a dark sky to make out the delicate details of his rings and to keep track of his swarm of moons.
Speaking of moons, the family of natural satellites orbiting Jupiter has just expanded dramatically. Over the last few weeks, observers in Hawaii have detected eight new faint worldlets in Old Jove’s tow. This brings the total of known Jovian moons to 52. All but the four bright moons found by Galileo in 1610 require very large telescopes, remote high mountaintops, and infrared detectors to easily see, but the antics of the Galileans make for wonderful entertainment as the gas giant planet rotates beneath them. As the brightest star-like object in the night sky, Jupiter is hard to miss as the evenings start to get milder.
The morning sky still hosts Venus and Mars. The latter is lurking among the stars of the southern summer Milky Way and can be seen low in the southeast crossing the top of the teapot-shaped asterism of Sagittarius at around 5:00 am. Venus becomes visible about half an hour later, low in the eastern sky as twilight gathers for another day.
