This is the Dudley Observatory Skywatch Line for Wednesday, October 3rd, and Thursday, October 4th, written by Louis Suarato. The 34% illuminated, waning crescent Moon sets at 3:34 p.m. Wednesday. Look for M44, the Beehive Cluster, 1 degree to the upper left of the crescent Moon before Thursday’s sunrise.. At approximately 600 light-years away, the Beehive Cluster is one of the closest open star clusters. M44 contains about 1,000 gravitational bound stars, estimated to be about 600 million years old. After sunset, Mars, Saturn, and Jupiter can be seen spanning 77 degrees from above the south-southeastern to the west-southwestern horizons. Venus and Mercury are too close to the Sun to see, with Venus heading toward the Sun, and Mercury moving away. Mercury will re-emerge in the evening sky during mid-month. Venus will reappear in the morning sky early next month.
While you are out looking at the crescent Moon during the early morning twilight, look to the south, or right of the Moon, about 25 degrees to Canis Minor’s brightest star, Procyon. Then scan another 25 degrees to Comet 21P/Giacobini-Zinner. This 7thmagnitude comet is to the upper left of Sirius, the brightest star in our sky. Another comet to keep track of is 41P/Wirtanen. This comet, discovered in 1948, returns for its trip around the Sun once every 5.4 years. In December, Comet 41P/Wirtanen will reach perihelion, its closest approach to the Sun, days before reaching its closest approach to Earth. The comet may reach 3rdto 6th magnitude during December.
On October 4, 1957, the Space Race began when the Soviet Union launched the satellite Sputnik-1 into Earth orbit. Traveling at 18,000 miles per hour, Sputnik completed 1,440 orbits in 3 months, about 43 million miles, before burning up in Earth’s atmosphere. Since then, 8,100 satellites have been launched by 40 countries. About 4,900 remain in orbit, with 1,900 that remain operational. The largest, and only habitable artificial satellite, is the International Space Station. The ISS is visible with the naked eye, and can be seen Thursday, beginning at 7:53 p.m. when it emerges from the northwest horizon. This -2.1 magnitude pass will sail past the bowl of the Big Dipper before disappearing into Earth’s shadow before reaching the constellation Perseus.
Weather permitting, the Albany Area Amateur Astronomers will host star parties this Friday and Saturday nights at the Landis Arboretum in Esperance, NY. Non-members are welcome as our amateur astronomers share views of planets, galaxies, nebulae, star clusters, and asterisms through their telescopes. It is also a great opportunity to test various telescopes before buying one of your own, or gaining insight on using one you may have recently obtained.