This Week’s Sky at a Glance, April 15 – April 22 ~by Curt Nason
With Jupiter being prominent in the east after twilight our eyes are also drawn to Spica, the 14th brightest star, which trails the planet by about seven degrees. Jupiter’s retrograde motion will carry it toward the star Porrima until mid-June, after which it will head eastward again to pass above Spica in September when they are setting an hour after sunset. When no bright planets are nearby, Spica is located by following the arc of the Big Dipper’s handle to bright Arcturus and driving a spike to Spica.
Spica represents an ear of wheat in the hand of the constellation Virgo the Maiden. In Greek mythology she was Demeter, the goddess of wheat or agriculture (Ceres in Roman mythology). The Sun passes through this constellation in harvest time, and it is in the head of Virgo at the autumnal equinox. Virgo is the second largest of the 88 constellations in terms of area of sky, trailing only Hydra the Water Snake. Coincidentally, it also trails Hydra in the sky, which can be seen stretching below Leo.
The region of sky encompassed by Virgo, Leo, Ursa Major and Boötes is known as the Realm of the Galaxies. The Galactic North Pole is in this direction, so we are looking away from the plane of our Milky Way galaxy and its obscuring dust clouds. Dozens of distant galaxies can be seen in a small telescope and many with binoculars. Spring is galaxy season for amateur astronomers.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 6:32 am and sunset will occur at 8:05 pm, giving 13 hours, 33 minutes of daylight (6:38 am and 8:09 pm in Saint John). Next Saturday the Sun will rise at 6:20 am and set at 8:14 pm, giving 13 hours, 54 minutes of daylight (6:26 am and 8:18 pm in Saint John).
The Moon is at third quarter on Wednesday, rising in the middle of the night and setting early afternoon. Jupiter is in position for observing all evening but at its best near midnight when it is higher. Its moon Europa emerges from the planet’s shadow at 8:55 on Tuesday, and Io does the same trick at 10:10 on Wednesday. Mercury is at inferior conjunction on Thursday, moving to the morning sky late in the month. Mars passes below the Pleiades and they are a scenic couple in binoculars toward the end of the week. Brilliant Venus rises around 5 am, about the same time Saturn is at its highest in the southern sky. Early risers might catch a few shooting stars from the minor Lyrid meteor shower on April 22.
Questions? You can contact Curt Nason here.