Skywatch Line for Monday and Tuesday, March 12th and 13th, 2018

This is the Skywatch Line for Monday and Tuesday, March 12th and 13th.

Now that Daylight Savings Time is in effect, the Sun sets at 6:58 PM; night falls at 8:32. Dawn begins at 5:36 AM and ends with the Sun rising at 7:11.

Brilliant Venus, in Cetus, blazes at minus 3.9 magnitude about 8 degrees above the western horizon. Venus, in binoculars or telescope, appears about 97 percent illuminated and 10.2 arc-seconds in size. Note that Venus climbs higher daily. It sets at 8:12 PM.

Mercury, in Pisces, lies about 4 degrees above Venus. It shines at minus 0.6 magnitude, appears about 6.8 arc-seconds in size and is about half illuminated. Mercury races higher in preparation for its best evening apparition of the year on March 15th, when it is 18 degrees distant from the Sun. After that date, it starts to sink back to the Sun. If the sky watcher has trouble finding Mercury, Venus can be a guide, since the two share a binocular field. Mercury sets at 8:32 PM.

At nightfall, Uranus, sharing Pisces with Mercury, is about 14 degrees high in the Southwest and about 16 degrees above Mercury. It glows at 6th magnitude, appears as a small 3.4 arc-seconds in our telescopes and sets at 9:51 PM.

Dwarf Planet 1Ceres remains a challenge object, since it emerges at seventh magnitude and a tiny 0.7 arc-seconds in size. It is best observed at 10:22 PM. Detailed finder charts are recommended to locate it near the star Sigma-3 (∑-3) Cancri.

After Midnight, the sky becomes alive with bright planets and the Moon. Jupiter rises first, at 11:57 PM, in Libra. At magnitude minus 2.2, Jupiter is the brightest object in the dim constellation. The Solar system’s largest planet appears as a large 41 arc-seconds in size about 29 degrees above the southeastern horizon. Jupiter is an astronomer’s delight. The Great Red Spot, a giant storm on Jupiter, is visible on Tuesday at 5:29 AM and on Wednesday at 1:19 AM. On Tuesday, Jovian moon IO disappears behind the planet at 4:46 AM. At 2:16 AM on Wednesday, the moon IO’s shadow begins its crossing on Jupiter and ends at 4:25 AM. IO, itself, begins its trek at 3:20 AM and exits Jupiter at 5:28 AM. Jupiter is best observed at 4:56 AM.

Mars rises in Sagittarius at 2:51 AM. The Red Planet shines at 0.6 magnitude and appears about 89 percent lit. By Dawn, it is about 20 degrees above the horizon, and 34 degrees from Jupiter. Notice that Mars continues to slowly brighten and grow larger.

Saturn, about 10 degrees below Mars, shares Sagittarius with Mars, and rises at 3:32 AM; it is easily located on top of the Teapot’s cap. Two Messier objects share the same binocular view with Saturn: bright Globular star clusters M22 and M28. Saturn also brightens and grows larger, but not as much as Mars.

Tuesday, the Moon rises in Capricornus at 5:12 AM. It is very obvious at minus 6th magnitude and appears about 16 percent phase. Wednesday, still in Capricornus, it is slightly dimmer and thinner, having risen at 5:49 AM.

At Midnight, a chain of stars wraps itself around Polaris, the Pole Star; this group is the constellation Draco, the Dragon. Draco is ancient, going back to the Mesopotamians. Most folklores picture dragons as we do, with horns, wings and multiple heads. Several Greek legends have the dragon guarding the Golden Apples or the Golden Fleece. In our night sky, Draco seems to continue his role as protector of the Pole Star. However, when the Pyramids were built, Thuban, one of Draco’s stars was, itself, the Pole Star. Several Pyramids were oriented to it.

Bookmark the permalink.