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March 7: Venus meets Saturn
Daylight saving time begins this morning at 2 A.M. local time. For regions that observe DST, clocks will “spring forward” from 2 A.M. standard time to 3 A.M. daylight time, meaning the Sun will rise and set an hour later than yesterday.
A few hours after dark — say, 9 or 10 P.M. local daylight time — cast your view north, where the large constellation Lynx sits above the North Star. One of many oft-overlooked deep-sky objects, NGC 2541, lies within the Lynx’s borders, and we’re going to take advantage of the moonless sky tonight to try for it.
Glowing at 12th magnitude from a distance of some 37 million light-years, this galaxy is a challenge because its surface brightness is low. Spanning nearly 7’, its loose, “fluffy” spiral arms surround a bright central core. Astronomers consider this an intermediate spiral galaxy because its core has no bar (an elongated structure, like the core of the Milky Way). Because it’s faint and doesn’t stand out well from the background, opt for as large a telescope as you have available. Long-exposure photography will pick it up and start to show detail as well.
You can find the galaxy by first locating 3rd-magnitude Iota (ι) Ursae Majoris, which marks part of the Great Bear’s front foot. From this star, simply slide about 7.5° east to land on NGC 2541.
Sunrise: 7:22 A.M.
Sunset: 7:00 P.M.
Moonrise: —
Moonset: 9:30 A.M.
Moon Phase: Waning gibbous (71%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location.
The Galilean moon Callisto disappears behind Jupiter in an occultation early on the morning of March 9. The catch is that the event is only visible from the western half of the U.S., but observers farther east can still watch as the moon closes in on the planet’s limb.
Shortly after local midnight on the 8th, Jupiter is some 50° high and slowly setting in the west, among the stars of Gemini. It hangs below the two bright stars marking the Twins’ heads, Castor and Pollux. Through a telescope, its Galilean moons are arrayed with two on each side of the planet: Europa and Ganymede lie to the east, while Callisto and Io sit to the west.
As the morning progresses, the moons noticeably shift positions. For two hours after midnight, Ganymede is closer to Jupiter to the east, with Europa farther away. The two moons are moving in opposite directions, however, and Ganymede passes north of Europa shortly after 2 A.M. EDT. On the other side of the gas giant, Callisto — which is moving eastward and passed north of westward-moving Io around midnight EDT on the 8th — is now moving closer to Jupiter’s western limb by the hour. The planet sets before the moon can reach it from the eastern half of the U.S., but observers in the Mountain and Pacific time zones will see Callisto disappear behind the limb around 3:30 A.M. MDT. The planet sets even for those on the West Coast before the moon completes its journey and reappears.
