This is the Dudley Observatory Skywatch Line for Monday, Memorial Day, May 28th and Tuesday May 29th written by Joe Slomka.
The Sun sets at 8:24 PM; night falls at 10:32. Dawn begins at 3:12 AM and ends with the Sun rising at 5:21.
The Moon and Jupiter occupy the early evening sky, while Venus prepares to set in the West. Monday’s Moon blazes in Libra with minus 12th magnitude and appearing nearly full. Tuesday, the Moon turns officially “Full” at 10:20 AM and migrates to Ophiuchus. On both nights, the Moon sets after sunrise takes place.
Jupiter shares Libra with the Moon on Monday. It gleams with minus 2nd magnitude and appears about 23º high. Telescopic observers can see the Great Red Spot at 11:41 PM on Tuesday. They can also witness Jupiter’s moon IO be eclipsed by the planet at 1:17 AM and reappear at 3:57 AM. Jupiter is best observed at 11:24 PM and sets at 4:27 AM.
Venus, in Gemini, lies moderately low in the southwestern sky. It glows with minus 4th magnitude, appears about 82% lit and is about 4º high. Venus sets about 11 PM.
Saturn rises in Sagittarius at about 10:30 PM. By Midnight, it glows at zero magnitude, appears 18 arc-seconds in size and lies about 12º high. It is best appreciated at 3 AM, when it is due South and situated 25º high for people to observe its magnificent ring system. Besides its rings, the planet is surrounded by binocular and telescopic star clusters M 22 and M 25.
Mars rises in Capricornus, 27º degrees east of Saturn; At 12:22 AM, it glows with minus 1st magnitude and appears about 90% illuminated. By its Transit at 4:58 AM, its 15 arc-second size and 21º height permits sky watchers to start seeing surface features. Mars is rapidly improving in anticipation of its July Opposition, when it is nearest to Earth.
Neptune rises in Aquarius at 2 AM. During the pre-Dawn hours it shines with 8th magnitude but is a tiny 2.3 arc-seconds in size and lies about 12º above the eastern horizon. Detailed star charts are needed; but once found, its distinctive blue-green color aids identification.
With Mars now prominent in the sky, let us consider this planet which resembles most to our own Earth. Giovanni Schiaparelli was an Italian astronomer, born in 1835. He studied under eminent astronomers and was made director of the Brera Observatory of Milan in 1860. He is recognized for discovering that meteor showers originate from comets. But he is most famous for his drawings of “canals” on Mars. In 1877, he called perceived markings on Mars “canali,” “channels.” However, the English translation became “canals,” which imply mechanical constructions. This announcement electrified the world, including Percival Lowell. A millionaire, Lowell used his private fortune to establish a state-of-the-art observatory in Flagstaff, Arizona, with the intent of studying these “canals.” Lowell’s observations not only agreed with Schiaparelli’s, but also amplified them. Lowell wrote popular magazine articles, depicting Mars as a dying planet, whose inhabitants were desperately digging canals to water their farms. By the 1920s, observations by other astronomers debunked these notions. In the 1960s, spacecraft sent back pictures of Mars as a desert without any “canali.” American robots prowled the Martian surface and failed to find any canals, but have found traces of water on the now arid planet. Schiaparelli and Lowell’s “canals” are now considered to be artifacts, caused by the brain’s attempt to make sense out of unfamiliar sights.