The moon reaches its new phase, when it is hidden from view beside the sun, Sunday evening. On Monday it will reappear as a fine silver crescent sitting over the western evening horizon. For the rest of the week, the moon will wax and shift eastward. For about 90 minutes after sunset on Tuesday, the moon will sit a palm’s width to the lower left of bright Venus. The pair will fit within the field of view of binoculars and make a lovely photo opportunity.
On Wednesday evening, in the western evening sky, the crescent moon will pass through the constellation Taurus (the Bull). The V-shaped face of the bull is formed by a large open star cluster known as the Hyades, one of the closest clusters to Earth. The moon will enter the “V” at about 8:30 pm local time and reach the midway point by the time moonset around 10:30 pm. A few hours later, observers in most of Uzbekistan and Kazakhstan, Central and Northern Russia, Northern and Eastern Scandinavia, Northern Greenland, and Northern Canada will witness the moon occult the bright, orange star Aldebaran, which sits at the southeastern corner of the bull’s face.
On the coming weekend, the moon will pass through Gemini (the Twins), and end the week with Sunday evening’s First Quarter Moon phase. The evenings leading up to first quarter are the best ones for looking at the moon under magnification. The steeply slanted sunlight creates breathtaking vistas along the terminator boundary line that divides the dark and light sides of the moon. To see the sights, sweep with binoculars or a telescope from pole to pole.
Venus continues to catch the eye as it slowly climbs higher in the western evening sky. It sets just after 10 pm local time. In addition to Venus’ encounter with the moon on Tuesday, our sister planet will also end the week by approaching the bright star cluster known as the Pleiades, or the Seven Sisters, in Taurus. Next Sunday evening, the cluster can be spotted with unaided eyes or, even better, with binoculars, just a few finger widths to the upper right of Venus.
At the same time that Venus is setting, mighty Jupiter will be rising in the east. The extremely bright planet dominates the southern overnight sky now. It reaches its highest elevation (about three fist diameters) above the southern horizon around 3 am local time, and then descends into the southwestern sky at sunrise.
The Great Red Spot takes about three hours to cross Jupiter’s disk. But the planet’s 10-hour rotation period (i.e., its day) means that the spot is only observable from Earth every 2–3 nights. If you’d like to see the GRS, use a medium-sized telescope (or larger). You’ll have your best luck on evenings with steady air — when the stars are not twinkling too much. The best times to try this week are: Monday, April 16 at 11:23 pm, Thursday, April 19 at 1:01 am, and Saturday, April 21 at 10:31 pm. Try to look within an hour before or after the times I’ve given.
The ringed planet Saturn will rise in the east shortly before 2 am local time this week. You should be able to see its yellow-tinted point of light until about 6 am, when it will sit about 2.5 fist widths above the southern horizon. Reddish Mars will rise about half an hour after Saturn. Look for it a generous palm’s width to the lower left of Saturn. Mars is steadily pulling away from Saturn. By next weekend, their separation will increase to a fist’s width.
Keep looking up to enjoy the sky! Via Chris Vaughan.