This is the Skywatch Line for Monday, and Tuesday, March 16th and 17th, written by Joe Slomka.
The Sun sets at 7:04 PM; night falls at 8:38. Dawn begins at 5:28 AM and ends with the Sun rising at 7:03.
The Moon appears in Sagittarius on both nights. Monday’s Moon reaches Last Quarter at 5:34 AM, 44% illuminated, rising at 2:25 AM and setting at 11:42 AM. Tuesday’s Moon is thinner, 34% lit, rising at 3:25 AM and setting at 12:33 AM. Wednesday, the Moon rises at 4:16 AM and sets at 1:30 PM, appearing 27% lit.
The early evening sky hosts one bright and one dimmer planet. Venus is the brightest, blazing with minus 4.2 magnitude, appearing 21 arc-seconds in size. Rising in Aries, the clouded planet is nearing greatest eastern elongation, which means it is almost at its most distant from the Sun. By civil twilight, it appears 37° high and 55% illuminated. Venus sets at 11:02 PM. Uranus, also in Aries, glows with zero magnitude, is 3 arc-seconds in size and 19° high. It sets at 10:10 PM.
The pre-Dawn sky is quite busy. Three planets, Mars, Jupiter and Saturn, occupy Sagittarius; Mercury hovers in Aquarius. Mars is the first to rise at 4:14 AM, shining with zero magnitude, almost 6 arc-seconds in size and 18° high. Jupiter follows right behind, rising at 4:19 AM, glaring with minus 2nd magnitude, about 36 arc-seconds in size and also 18° high. Saturn trails, rising at 4:44 AM, shining with zero magnitude, nearly 16 arc-seconds in size and 16° high. Mercury lags far behind and lower, rising at 6:08 AM, 8 arc-seconds and 4° high.
These four heavenly bodies continue last week’s dramatic parade. Moderately low in the southeastern sky, Mars, Jupiter and Saturn form a magnificent chain, with Mars being highest and dim. Tuesday and Wednesday the planets are joined by the Moon. Tuesday finds the moon to Mars’ right; Wednesday finds the Moon under both Mars and Jupiter, with Saturn behind. Mercury is only 4° low in the East and may be hidden by the rising Sun’s glare.
The important, but dim, constellation Cancer lies bracketed between much brighter Gemini, Leo, and Hydra. The constellation itself is ancient, part of the original Mesopotamian zodiac. The first day of summer, this year on June 20, is the Sun’s highest point of the year. In ancient Greece, this event took place in the constellation of Cancer. Since Cancer is located on the ecliptic, visits by the Sun, Moon and planets are common.
Cancer is an unusual constellation; its brightest feature is not a star, but a cluster of stars. If you live away from city lights, the first thing you see is a hazy patch in the middle of the constellation. This is M-44, the Beehive Cluster. When observed in binoculars or low power telescope, it resolves into hundreds of stars. These are born out of a common gas cloud and are found in the spiral arms of our Milky Way galaxy.