August 2000

by Steve Stefanik

August 2000 will be an astonomically active month with an asteroid, a debilitated comet, a planetary opposition, a meteor shower and six planets visible to the naked eyes.

Last month’s arrival of a "new" comet into the solar system LINEAR C/1999 S4 was so quick (by cometary standards) that you may have missed it as it swept across the northern sky just below the constellations Perseus, Cassiopeia, Ursa Minor (the Little Dipper) and Ursa Major (the Big Dipper). Although it did not rival the naked-eye comets Hale-Bopp and Hyakutake of two and three years ago, it was fairly spectacular through binoculars or even a small telescope sporting a modest "tail". What was spectacular was its firey demise as it reached perihelion (closest approach to the sun) breaking apart from the gravitational force of the sun. LINEAR is now low on the western horizon headed into the constellation Virgo and will drop out of view 90 minutes after sunset. It was in the true sense a "short term comet", never before seen and it may never be seen again so if you missed it there will be no next time!

If you have a telescope you could get to see an asteroid this month. Scan the southern sky above the "teapot" asterism in the constellation Sagittarius for the 10th magnitude asteroid Harmonia. It should be easy to follow this minor planet as it arcs slowly across this region of the sky.

The annual allure of the Perseid meteor shower peaks on the night of August 11-12. These bright and swift "shooting stars" streak across the summer sky every few minutes emanating from the constellation Perseus in the northeastern sky.

The planet Neptune reached opposition last month and can be found with binoculars in the constellation Capricorn not far from the planet Uranus which reaches opposition on the 11th of this month. Unlike magnitude +7.8 Neptune which can only be spotted with binoculars, Uranus at magnitude +5.7 can be seen with just your eyes if you live or get away from city lights. Opposition is always the best time to view any planet since it is directly opposite the sun from us so it is always at its brightest.

The planets Jupiter and Saturn rise around midnight returning to the night-time sky. The two gas giants have swapped places since we saw them last because Jupiter is faster in its orbit being closer to the sun so it has passed Saturn and now lies farther east than Saturn in the constellation Taurus. The pair will be with us throughout the rest of the summer, fall, winter, and into next spring.

The planet Mercury is still visible 30 minutes before sunrise in the east the first few days of August but quickly sinks into the solar glare. It reaches its brightest -1.2 magnitude on August 9.

Mars makes its way above the eastern horizon and into visibility barely. On August 10 you may be able to catch a glimpse of its tiny +1.7 magnitude disk about 0.2 degree lower and to the left of Mercury.

Finally the planet Venus can be spotted very low on the western horizon about 20 minutes after sunset. By the end of the month you can try looking for it 30 to 40 minutes after sundown. On August 30th it will be about 3 degrees to the lower left of the thin crescent moon.