Skywatch Line for Monday and Tuesday August 7th, and 8th, 2023

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday August 7th, and 8th, written by Joe Slomka.

The Sun sets at 8:09 PM; night falls at 10:01. Dawn begins at 4:01 AM and ends with the Sun rising at 5:54.

Northeastern Aries houses the Moon on both nights. Monday’s Moon set at 12:58 PM, rises at 11:23 PM and sets at 2:11 PM, Tuesday. Tuesday’s pre-dawn sky sees the Moon 37° high at 3 AM, 31 arc-minutes in size, 44% illuminated, very close to Jupiter and becomes officially Last Quarter at 6:29 AM. Tuesday’s Moon rises at 11:51 PM. By 3 AM on Wednesday, it is 31°, 41% crescent, 4° above Uranus, 13° from Jupiter, and sets at 3:21 PM.

Venus is approaching Aphelion (furthest from Sun) and will be lost in the solar glare.

Two planets and one minor planet are visible by 9 PM. Mercury and Mars share Leo and both are close to the horizon, requiring a clear western horizon. Mercury is closest to the horizon, only 3° high, zero magnitude, 7 arc-seconds in size, 52% lit and sets at 9:04 PM. Mars is a bit further, almost 4 arc-seconds, 7° high, 97% brightened and sets at 9:26.

Saturn rises in Southwestern Aquarius at 9:03 PM, shining with zero magnitude, a large 18 arc-seconds, highest at 2:23 AM and is 24° high at 5 AM. Neptune, in Pisces, 8° East of Saturn, glows with 7th magnitude, 2 arc-seconds, rises at 9:50 PM, highest at 3:44 AM and 41° high at 5 AM.

Gas Giant Jupiter, shares southeastern Aries with Uranus, rises at 11:41 PM, glimmers with minus 2nd magnitude, a large 40 arc-seconds and is 55° at 5 AM. Uranus brings up the rear, 13° distant from Jupiter, rises at 12:04 AM, glowing with 5th magnitude, 3 arc-seconds and is 53° high at 5 AM.

Note that the Moon, Jupiter and Uranus appear crammed into a space only 14° wide at 5 AM on Tuesday.

For those with telescopes, Comet 103P/Hartley is visible in the Southwest Dawn sky, near M31 (Andromeda Galaxy). It glows with 10th magnitude, 86% lit and highest at 4:26 AM.

By nightfall, Capricornus, Aquarius, Pisces and Cetus dominate the southern sky. All are water-based. Capricornus is a unique constellation: The Sea-Goat; the creature has the head of a goat, but the body of a fish. This part of the Zodiac is truly ancient; Sumerians identified it as early as 1600 BC. A royal seal, from the town of Ur, is on display in the Boston Museum; the seal bears the image of Capricornus, just as pictured today. Boundary markers of Mesopotamian kings also depict Capricornus as we do. The source of this animal is a mystery. A people far removed from any large body of water invented it. The Goat-Fish was associated with the god Ea, the master of creation and the god of underwater seas, including fresh water springs. Ea resembles the Roman god Neptune. In 1846, the astronomer Galle discovered the planet Neptune in Capricornus. The constellation inspired several English words.

To caper is to frolic like a goat; when people caper, they are called capricious. The famous island of Capri was named “the isle of goats”. Cornucopia is a horn of plenty.