This is the Dudley Observatory Skywatch Line for Wednesday, October 7th, and Thursday, October 8th, written by Louis Suarato.
The 68% illuminated, waning gibbous Moon rises at 9:44 p.m. Wednesday in the constellation Taurus. This may be one of your last opportunities to see Mercury about 30 minutes after sunset. Look low over the west-southwest horizon. Binocular will help, but be careful of the bright glow of the sunset. At that time, Saturn and Jupiter will emerge about 25 degrees above the southern horizon. Jupiter will be to the right, and is the brighter of the two planets. The gas giants are about 7 degrees apart. Thursday night, beginning at 7:29 p.m., Jupiter’s moon Callisto is occulted. An occultation is an event when one object is hidden by another object that is between the first object and the observer. Callisto’s orbit will be taking it behind Jupiter. Callisto’s occultation ends at 11:40 p.m., when it reappears from behind the planet. At 7:43 p.m., Io begins its transit across Jupiter. Io’s transit ends at 11 p.m. Thursday. At 9:02 p.m., Io’s shadow will cross the planet. Io’s shadow transit ends at 11:20 that night.
Mars rises at 6:52 p.m., Wednesday in the constellation Pisces. As Mars approaches its opposition on October 13th, it will be the best time to observe the red planet for the next 15 years. Mars opposition occurs only 7 days after Mars closest approach to Earth in years. On October 6th, Mars will be within 38,568,819 miles of Earth. The combination of Mars’ close approach, and its opposition increases it brightness to -2.6 magnitude. Venus rises at 3:39 a.m., Thursday, in Leo.
The Draconid meteor shower peaks overnight Wednesday through Thursday. This is considered a variable meteor shower because the number of meteors per hour depends on where Earth’s orbit intersects the comet 21/P Giacobini-Zinner’s trail in any given year. There were outbursts in 1933 and 1946, and in 2011, European observers were treated to over 600 meteors per hour. The radiant of the Draconids, or the point at which the meteors will originate, is the constellation Draco. Draco is a circum-polar constellation that will be above the Big Dipper after sunset, and will be wrapped around the Little Dipper during Thursday’s early morning hours.