Friday, March 17
Mercury reaches superior conjunction at 7 A.M. EDT. The small planet will return after sunset near the end of March.
The waning Moon means evening skies are completely clear for stargazing. After dark, you’ll have some time to enjoy the rich treasures of the constellations Orion and Taurus, slowly setting in the west. Start with Taurus, the current home of magnitude 0.7 Mars, situated just above a line drawn between Alheka and Elnath, which mark the tips of the Bull’s horns. The Red Planet displays a 7″-wide disk whose features might be tricky to discern by eye, though high-speed video capture may do the trick. Around 10 P.M. EDT, the dark smudge of Sinus Meridiani is near the center of the disk, just as Syrtis Major is rotating off and the lighter-colored Tharsis region is rotating on.
Some 25° below Mars is the Pleiades star cluster, easy to spot even with the naked eye. This grouping is often called the Seven Sisters for a reason — how many of its stars can you see? Try looking with averted vision, turning your gaze off to the side and glimpsing the cluster out of the corner of your eye.
Just east of Taurus in the sky is Orion the Hunter, whose great nebula M42 is one of observers’ favorite targets to enjoy. This large star-forming region glows a soft green when viewed through a telescope and surrounds the four bright stars of the Trapezium in its center. These young, hot suns are in the process of blowing away the cloud that birthed them, leaving behind a darker void in their immediate vicinity — can you see it through your scope?
Sunrise: 7:09 A.M.
Sunset: 7:09 P.M.
Moonrise: 4:59 A.M.
Moonset: 2:15 P.M.
Moon Phase: Waning crescent (22%)
*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, March 18
It’s prime Messier marathon time! With a slim crescent Moon present for only a short time before sunrise, this is the best weekend of the year to attempt catching a glimpse of all 109 Messier objects in a single overnight sprint. According to amateur astronomer Tom Polakis, skywatchers located between 7° and 33° north latitude have the potential to score every object this weekend. That range is calculated by determining whether globular cluster M30 can be spotted just before sunrise, as well as open cluster M52’s altitude above the southern horizon.
If you’re up for the challenge, make sure you’re ready with large binoculars or a small scope shortly before sunset. However, don’t ever begin using any optical equipment until the Sun has fully set from your observing site, which is heavily location dependent and may be at a time slightly different from that given below. Similarly, make sure to put down your optics before sunrise is set to begin from your location.
For a tried-and-true list of Messier marathon targets, check out the late Don Machholz’s suggested search sequence. And if you aren’t up for a full marathon, former Astronomy columnist Glenn Chaple has a great short list of easy Messier objects to whet your appetite, including M35, M42, M44, M45, M81, and M82.
If weather or sleep deprivation prevents you from running the full marathon this weekend, don’t worry — next weekend provides a backup opportunity for most observers.
Sunrise: 7:07 A.M.
Sunset: 7:10 P.M.
Moonrise: 5:43 A.M.
Moonset: 3:34 P.M.
Moon Phase: Waning crescent (13%)
Sunday, March 19
Whether you’re still awake at the tail end of your Messier marathon or simply an early riser, there’s another challenge to try this morning in the predawn sky. About half an hour before sunrise, see if you can spot Saturn and the delicate crescent Moon rising together in the east.
Our satellite is less than 10 percent illuminated and a mere 2° high 30 minutes before sunrise. Saturn sits just less than 5.5° to its upper left (north-northeast), glowing softly at magnitude 0.9 and 4.5° high. You’ll likely need binoculars or a telescope to pick out the ringed planet against the quickly brightening sky. Its disk stretches about 15″ across, while its rings span more than twice that distance. Again, make sure to stop using any opticals several minutes before the Sun is set to rise from your location.
A few hours later, the Moon will pass 4° due south of Saturn at 11 A.M. EDT. Our satellite also reaches perigee, the closest point to Earth in its orbit, at 11:12 A.M. EDT. At that time, Luna will sit 225,369 miles (362,696 kilometers) away.
Sunrise: 7:05 A.M.
Sunset: 7:11 P.M.
Moonrise: 6:18 A.M.
Moonset: 4:52 P.M.
Moon Phase: Waning crescent (6%)