Skywatch Line for Monday and Tuesday, February 19th and 20th, 2018

This is the Skywatch Line for Monday and Tuesday, February 19th and 20th.

The Sun sets at 5:34 PM; night falls at 7:07. Dawn begins at 5:11 AM and ends with the Sun rising at 6:45.

The Moon dominates the twilight sky. The 4-day-old Moon inhabits Cetus, shines at minus 7th magnitude and appears about 16 percent illuminated. Tuesday, the Moon migrates to Pisces, appears much brighter and about 25 percent lit. It sets at 9:32 PM on Monday, and at 10:38 PM on Tuesday.

Uranus inhabits Pisces, with the Moon dazzling about 8 degrees away. Uranus shines at 6th magnitude, is 3.4 arc-seconds in our binoculars and telescopes and is about 43 degrees high above the southwestern horizon. It sets about 10:09 PM.

Neptune shares Aquarius with Venus. Both lie low above the southwestern horizon. Venus blazes at minus 4th magnitude, 3 degrees high and appears about 98 percent full. Neptune, 2 degrees above Venus, glows at 8th magnitude, is a tiny 2.2 arc-seconds. Venus sets at 6:19 PM, Neptune at 6:32. Venus marks the ending of the bright planet drought in the evening sky. Notice that it climbs higher daily and will delight us through Autumn.

Dwarf planet 1Ceres occupies Cancer, shining at 7th magnitude and appearing a tiny 0.7 arc-seconds. It is best observed at 10:56 PM and sets after sunrise. Uranus and 1Ceres require detailed finder charts from astronomical media.

Jupiter rises in Libra at 12:21 AM. At minus 2nd magnitude, it provides opportunities for early rising observers. Tuesday pre-dawn presents the Great Red Spot (a giant Jovian storm) centered on the planet’s face at 2:07 AM. The moon IO reappears from behind Jupiter at 1:40 AM. Ice-covered Europa’s shadow begins to cross Jupiter at 2:07 AM and exits at 4:22 AM.

Mars, 22 degrees below Jupiter, is positioned in Ophiuchus, rising at 2:15 AM. It shines at 1st magnitude and appears 89 percent lit. The Red Planet steadily grows brighter and larger during the Spring and Summer. Last week, Mars was quite close to Antares, its rival; now, 7 degrees distant, it creeps away from the Scorpion’s heart. Mars is best observed during the pre-dawn hours.

Saturn brings up the rear, rising at 3:49 AM in Sagittarius. The 0.6 magnitude planet is about 11 degrees high at Astronomical Dawn, providing decent binocular views of its glorious rings.

This past Friday was the Chinese New Year. China, like the Hebrew and Islamic religious calendars, uses a lunar calendar. Lunar calendars have twelve lunar months, averaging 29 ½ days; lunar years contain about 354 days. Chinese emperors added extra months seven times within a 19-year cycle, thus bringing lunar and solar calendars into sync. Chinese number their months, but assign names to the years according to a complicated formula. The year name has two parts. The first part refers to a 60-year cycle of ten names, which repeat. The second part names the years after the twelve animals of the Chinese zodiac. This year is the Year of the Dog, followed by Horse, Sheep, Monkey, Rooster, Pig, Rat, Ox, Tiger, Hare, Dragon and Snake.

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