The Sky This Week 3-11 July 2003
The Moon waxes in the sultry summer evening sky, competing with fireworks displays on the 4th. She doesn’t pass any bright objects until the evening of the 7th, when she’s about five degrees northeast of the star Spica, and the 10th, when she’s some three degrees away from Antares, glowing like a tiny topaz in the southern sky as the midnight hour approaches. First Quarter occurs on the 6th at 10:32 pm Eastern Daylight Time.
Earth passes aphelion on July 4th, marking our farthest distance from the Sun. It is also the time when our fair planet is traveling at its slowest speed in its nearly billion kilometer annual circuit of the day-star, plodding along at a mere 100,000 kilometers per hour or so. The coincidence with Independence Day is just that, and it is a temporary arrangement at that. Due to two independent but combined precession effects, the dates of aphelion and perihelion arrive a bit later with each year. In about 500 years they will occur a week or so later than they do now.
The summer sky that greets the Moon is now beginning to fill with the bright stars of Summer. Spring’s beacon, Arcturus, still hangs high in the west at midnight, but the signature constellations of Leo and Virgo are dropping over the horizon, replaced by the three bright blue stars of the Summer Triangle and the misty veil of the Milky Way. While the Moon washes out the view of our home galaxy by the week’s end, late-night skywatchers can see it from dark locations at around midnight after Luna has set. That wheeling band of light is a wonderful target for binoculars, revealing clouds made up of stars interspersed with dark voids of interstellar dust. This is the stuff we’re made of, and it is a humbling experience to view it from a secluded space at the shore or in the mountains.
Jupiter still glows in the western sky at dusk. You can now only see him in the early stages of twilight, glimmering about 15 degrees above the horizon at 9:00 pm. A cold world such as Old Jove seems to be happiest in a colder sky, so we’ll have to wait until the crisp mornings of autumn to get our next good view if this distant hulking world
Vacationers at the beach or up in the mountains will be able to greet ruddy Mars as he now rises just before midnight. The red planet is growing steadily brighter from night to night, and his rapid pace through the stars is beginning to abate as the Earth catches up to him. He’s now well worth a look through the telescope as his angular size is almost as big as it was during the peak observing time of his 2001 apparition. A recent “weather report” from amateur observers indicates that a large dust storm has begun in the planet’s southern hemisphere. Hopefully it won’t spread around the entire planet’s surface to obscure the earthbound view.
