This is the Dudley Observatory Skywatch Line for Monday, and Tuesday, November 25th and 26th, written by Joe Slomka.
The Sun sets at 4:32 PM; night falls at 6:25. Dawn begins at 5:19 AM and ends with Sunrise at 6:49.
Monday’s Moon sets at 4:07 PM; Tuesday’s Moon sets at 4:45 PM and turns officially “New” at 10 AM.
About 40 minus after Sunset, Venus and Jupiter lie close together and low to the southwestern horizon. On Tuesday’s Dusk, they are positioned 3° apart with Jupiter lowest. Venus, Jupiter and Saturn share the constellation Sagittarius. Venus and Jupiter set at 5:56 PM; Saturn hangs on for another 2 2/3 hours before setting at 7:23 PM. Even though low on the horizon, its maximum tilt to us permits views of its glorious rings. In the coming weeks, note how Venus gradually sneaks up on Saturn.
Neptune, in Aquarius, sets at 12:24 AM. Uranus, in Aries, is best seen at 9:41 PMand sets at 4:30 AM. Both appear as tiny blue-green dots amid the stars. Binoculars or telescopes assist in finding them, along with finder charts from astronomy magazines and websites.
Mars rises at 4:32 AM in Virgo as a first magnitude red dot 4 arc-seconds in size. Mercury in nearby Libra rises at 5:16 AM. Wednesday’s dawn sees Mercury only 2° from Spica, the brightest star in Virgo.
Since 2004, the Cassini space probe has been circling Saturn. While the planet was the main focus of the mission, the probe also studied the largest moon in our Solar System, Saturn’s Titan, over 5100 km in diameter. Using radar and infrared sensors, the probe mapped the giant satellite; NASA released the map earlier this week. It turns out that Titan has the same geologic processes as Earth. Equatorial dunes are not made of sand but hydrocarbons; the dunes can be as high as the Statue of Liberty. Hydrocarbon lakes gather around the poles. Plains constitute 2/3 of Titan’s surface. Labyrinths, craters and hummocks fill out the inventory.
Winters in the Northeast are notoriously cloudy. However, when skies are clear, the night sky presents a riot of brilliant stars and constellations that seem close enough to reach out and touch. In fact, twenty-three of the fifty brightest stars are visible in tonight’s sky. Orion, the Dogs and Taurus account for the majority of the brightest stars in the heavens. Sirius is not only brightest on this list, but also second only to the Sun in luminosity; it is also the leading light of Canis Major, the Large Dog. About half of the list lies relatively close to us; the other half is intrinsically brighter, though further away. So, if it is clear, bundle up and enjoy Nature’s sky show.