Friday, March 31
The Moon reaches apogee, the farthest point from Earth in its orbit, at 7:17 A.M. EDT. It will then sit 251,605 miles (404,919 kilometers) away.
A few hours earlier, Venus passes 1.3° north of Uranus at 2 A.M. EDT. The two planets are visible in the evening, still less than 2° apart. Around sunset, you’ll easily spot magnitude –4 Venus some 30° high in the west. Let the sky darken just a little, then pull out binoculars or a telescope and look to the planet’s south (lower left) for magnitude 5.9 Uranus. Its dim, tiny disk will pop out more readily as darkness falls.
Closer to the horizon, Mercury (10° high 20 minutes after sunset) and Jupiter (3° high 20 minutes after sunset) are still visible, if briefly. Meanwhile, ruddy Mars still flies high in the sky, up above the V-shaped constellation Taurus.
Once the sky has darkened and you’ve had a chance to enjoy the planetary parade, turn your attention to the finest globular cluster the spring sky has to offer: M3. Located in Canes Venatici, you’ll find it about halfway between the Hunting Dogs’ alpha star, Cor Caroli, and Arcturus (Alpha [α] Boötis) in the Herdsman. At magnitude 6.2, the cluster may be just at the edge of naked-eye vision from a dark site, though tonight’s bright Moon may dash your chances of spotting it. That’s okay — binoculars or a telescope will easily reveal the dense ball of stars. The former will show it as a fuzzy patch of light, while the latter should start to resolve myriad suns around its edges, with more appearing the larger your aperture.
Containing tens of thousands of stars, M3 spans nearly 20′ on the sky, with a dense center just over 1′ wide. The cluster is rising after sunset and highest overnight.
Sunrise: 6:46 A.M.
Sunset: 7:23 P.M.
Moonrise: 1:59 P.M.
Moonset: 4:29 A.M.
Moon Phase: Waxing gibbous (74%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
Saturday, April 1
Mars lies directly above (northeast of) open cluster M35 in Gemini this evening. About an hour after sunset, you’ll find the Red Planet roughly 60° high in the west and shining at magnitude 0.9. It lies near one foot of Gemini the Twins, about 3° due north of Propus (Eta [η] Geminorum).
Mars now appears about 6″ across, so discerning surface features is difficult unless you’re experienced with high-speed video capture. While you may not get much from the Red Planet, drop about 1.8° down (southwest) to find M35, a 5th-magnitude open cluster spanning roughly the size of the Full Moon. Although this target is technically visible with the naked eye, the Moon’s pervading light will again likely render it invisible without some optical aid. But because this is a bright open cluster, any magnification should offer a glittering view — and in fact, lower power and a wider field of view are desirable here. If you are using higher power, look for NGC 2158, a fainter (magnitude 8.6), more compact open cluster just ¼° southwest of M35.
Finally, slide back to Propus: This is a well-known variable star whose brightness changes by some 50 percent over the course of roughly two-thirds of a year. Compare it with nearby Mu (μ) Geminorum to its east — Mu is a steady magnitude 2.9, while Propus swings between magnitudes 3.3 and 3.9. So, at its dimmest, Propus is a full magnitude fainter than Mu, while at its brightest, the two are much closer in appearance.
Sunrise: 6:44 A.M.
Sunset: 7:24 P.M.
Moonrise: 3:02 P.M.
Moonset: 5:01 A.M.
Moon Phase: Waxing gibbous (82%)
