On March 2, 2004 the European Space Agency launched the Rosetta mission with the hopes of visiting a comet in orbit around the Sun. Now, after ten years and over 6.4 billion miles logged, that hope has become a reality as Rosetta has rendezvoused with comet 67P in an orbit located 252 million miles from Earth halfway between the orbits of Jupiter and Mars. This was no small feat as the comet is traveling at 34,000 miles per hour. The rendezvous took place on August 6 and Rosetta will accompany the comet for the next year as it swings about the Sun and heads back to the furthest point in its orbit beyond Jupiter. For the next several weeks Rosetta will scan the comet’s surface for a place for its on-board lander, Philae, to set down hopefully on Nov. 11th. The lander will have several instruments on board that will analyze the gases escaping from the surface, search for organic molecules, measure temperatures and investigate the structure of the nucleus. The mission is scheduled to end in December 2015.
Focus on the Planets
Mercury is a lost cause until late in the month when it may be spotted very low in the west as evening falls. Look for Mercury to the lower right of the new crescent Moon on the 26th.
Venus appears only an hour before sunrise as the month opens and this time shortens as the days pass. Look for Venus very close to the bright star Regulus low in the east about a half hour before sunrise on Sept. 5. Jupiter reigns high to the pair’s upper right.
Mars rises in the southwest at sunset and sets three hours later. On Sept. 5, Mars is situated between Saturn to its right and Antares to the left midway up on the southwest horizon an hour after sunset. Mars will prove to be a disappointment to viewers displaying little, if any, detail except its distinctive ruddy color.
Jupiter is well up on the eastern horizon appearing around 4:00 a.m. All four of its major moons are visible by telescope. On Sept. 20, look for Jupiter just to the upper left of the crescent Moon.
Saturn rises low in the southwest at sunset with the interval between sunset and the setting of the planet shortening each night. Saturn’s rings are still open but the short time the planet is in view and its proximity to the horizon cuts down on the spectacular views seen earlier in the year. On Sept. 27, Saturn is nestled with the crescent Moon with Antares and Mars slightly above and to the ringed planet’s left.
Blue-green Uranus in Pisces and blue-gray Neptune in Aquarius are high in the east-southeast as darkness falls and up most of the night available with binoculars. Sky and Telescope magazine gives a finder chart for these two far distant planets in the September issue.
September Events
1 Sunrise, 5:57 a.m.; sunset, 7:13 p.m. This is the peak night for the Aurigid meteor shower. A sparse stream of up to 6 meteors per hour of bright, fast-moving meteors.
2 Moon in first quarter, 7:11 a.m.
5 Look to the east a half hour before sunrise where Venus and Regulus are very near together. At night, about an hour after sunset, from right to left Saturn, Mars, and Antares lies in line on the southwest horizon.
8 Full Moon, 9:38 p.m. As the full Moon nearest the fall equinox, this is the Harvest Moon. The Moon is also at perigee, or nearest approach to the Earth, thus larger than normal tides can be expected.
15 Moon in last quarter, 10:05 p.m. Aldebaran, the “Red Eye of the Bull,” is to the right of the Moon at dawn.
17 The Sun enters Virgo on the ecliptic.
20 Jupiter is to the upper left of the Moon an hour before sunrise. The Moon is at apogee or farthest distance from Earth
22 Autumnal or fall equinox,10:29 p.m. This is the point where the Sun crosses the equator into the southern hemisphere. The Sun enters the astrological sign of Libra at the equinox.
24 New Moon, 2:12 a.m.
27 Saturn is very near to the crescent Moon low in the southwest an hour after sunset. Mars is well to the upper left of Saturn with Antares directly below the Red Planet.
30 Sunrise, 6:31 a.m.; sunset, 6:18 p.m.
Send astronomical queries to Clair Wood at cgmewood@aol.com or care of the Bangor Daily News, Features Desk, P.O. Box 1329, Bangor, ME 04402.