Skywatch Line for Friday, March 21, through Sunday, March 23, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, March 21, through Sunday, March 23, written by Sam Salem.
On Friday, Sun rises at 6:56am and sets at 7:09pm; Moon rises at 1:59am and sets at 10:17am.
Last-quarter Moon occurs on Saturday morning at 7:29 am.
Moon rises around 3am Saturday morning. Catch the Moon when it’s higher just before Saturday’s dawn begins. You see the Moon at almost the very farthest south it can ever possibly get at declination –29½°.
On the Saturday and Sunday, the waning Moon will slide past the asterism of the Teapot of Sagittarius the Archer in the morning sky. You can catch them before dawn. The Teapot is an easy-to-see pattern in our night sky. It’s now coming back to the eastern sky before sunrise. This pattern of stars marks the direction to the center of our Milky Way galaxy.
By Saturday, Venus will be passing a wide 8.4° to the celestial north of the Sun as seen from our mid-northern latitudes. Venus is at inferior conjunction. Once you pick up Venus with the naked eye, try to detect its crescent shape. In a telescope, Venus now shows as a hairline crescent, just 2% or 1% illuminated.
On Saturday and Sunday, Venus will appear in the morning sky close to the eastern horizon about 15 minutes before sunrise, and in the evening sky very close to the western horizon about 10 minutes after sunset. It will be difficult to spot in the bright twilight on these occasions. This weekend, Venus sets while twilight is still bright.
Mars, magnitude +0.1 near the heads of Gemini, comes into view in twilight as a steady orange spark very high toward the south. It continues to fade. As darkness deepens, watch for fainter Pollux and Castor to emerge near it. The triangle that the three of them make is changing faster now, as Mars appears to accelerate away from the end of its retrograde loop.
Jupiter shines bright white, magnitude –2.2, high in the southwest at dusk, in Taurus 36° lower right of Mars along the ecliptic. Below Jupiter shines orange Aldebaran. Farther to Jupiter’s lower right are the Pleiades. Later in the evening Jupiter moves down toward the west.
Saturn is too close to the Sun right now to see. It’s hidden in the background of the Sun. This weekend, Saturn’s angle of tilt toward Earth places the rings edge-on from our vantage point. This happens approximately every 13 to 15 years. Saturn’s rings are remarkably flat. When they’re turned precisely edge-on to us, they’ll seem to disappear.
The southern constellation Puppis, is now briefly, at its highest shortly after dark. It’s weakly highlighted by the Milky Way. Puppis is the prow or the stern of the legendary Greek ship Argo. The dim, northernmost stars of the stern’s stick figure lie less than a fist-width to the left of the bright triangle forming Canis Major’s tail and hindquarters.
The 3rd-magnitude open cluster NGC 2451 sits way down below those top stars. NGC 2451 is very low at declination –38°. Find an observing spot with a low view due south and catch it while you can.