This is the Dudley Observatory Skywatch Line for Monday and Tuesday, May second and third written by Joe Slomka.
The Sun sets at 7:57 PM; night falls at 9:49. Dawn breaks at 3:54 AM and ends with the Sun rising at 5:46.
By civil twilight, only one planet, Jupiter is easily seen, at minus 2.2 magnitude. Jupiter has already risen by sunset; it is best observed at about 9:10 PM. Days are growing longer, so opportunities for spotting shadows on Jupiter are growing slim. However, the Great Red Spot, a giant storm on Jupiter, is visible to telescopic observers at 2:09 AM, Wednesday. Jupiter sets at 3:42 AM.
Mercury is also in the western twilight sky. However, it is quite low, about three degrees high, and dim, only third magnitude. This poses a challenge for the observer, who needs an unobstructed horizon to even try for success. Mercury sets at about 8:52 PM, and is preparing for its Monday, May 9thtransit across the Sun. The Dudley Observatory and miSci will have telescopes and other instruments that provide safe ways to view the Sun and Mercury.
Mars, Saturn and the star Antares make their appearance at Midnight. Mars rises first, at 9:50 PM in Scorpius. Mars is also preparing for its own special event – its opposition. Every two years, Mars approaches Earth. This time it is the best in eleven years. As May begins, it is retrograding, moving westward. During the month, it steadily becomes brighter, and larger in our instruments. Binocular and telescopic sky watchers are beginning to see details on the Martian surface. The Albany Area Astronomers will host star parties, weather permitting, this month. The public is invited to see Mars up close. Mars is best seen at about 2:30 AM and sets during daytime.
Saturn, in Ophiuchus, follows Mars a half-hour later early in the month; later, due to Mars’ retrograde motion, it lags to an hour behind. Saturn, also, is becoming brighter and larger in our eyepieces. It will have its own opposition in early June. The Saturnian rings are tipped almost to maximum for our enjoyment. Depending on telescope size, several of Saturn’s 62 moons are visible. Astronomy magazines, websites and apps assist the viewer in identifying them.
Saturn, Mars and Scorpius’ brightest star, Antares, fly in a triangular pattern all month. However, again due to Mars’ rapid westward motion, the gap between Mars and Saturn increases.
Neptune rises in Aquarius during Astronomical Dawn. It lies low on the eastern horizon, appears at about eighth magnitude, and disappears as the sky brightens.
The Moon rises at 3:59 AM Tuesday, it emerges in Pisces and blazes at minus seventh magnitude. It looks about 16 percent illuminated. Wednesday, it rises in Cetus at 4:35 AM, shining at minus 5.1 magnitude and only 9 percent illuminated. Wednesday finds the Moon only six degrees above the eastern horizon. This is the last easily seen Old Moon of this lunar month.