Skywatch Line for Monday and Tuesday, July 15th and 16th, written by Joe Slomka

This is the Dudley Observatory’ s Skywatch Line for Monday and Tuesday, July 15th and 16th, written by Joe Slomka.

The Sun sets at 8:30 PM; night falls at 10:37. Dawn begins at 3:25 AM and ends with Sunrise at 5:32.

The 9-day-old Moon rises in southern Libra at 3:16 PM, highest at 8:11 PM, appears 30 arc-minutes in size, 70% illuminated 25° high at 9 PM and sets at 12:58 AM on Tuesday. Tuesday’ s Moon rises at 4:24 PM, also 30 arc-minutes 78% lit, 22° highest and sets at 1:29 AM on Wednesday.

Mercury and Venus hug the western horizon on both nights. Mercury is first to be visible, in Leo, zero magnitude, 8° high, 54% lit, 7 arc-seconds and sets at 9:48 PM, when it begins to sink into the Sun’ s glare. Venus is located in Cancer, 15° above Mercury, blazing with minus 4th magnitude, 9 arc-seconds, 2° high in the Northwest and sets at 9:08 PM. Dwarf Planet 1Ceres in southern Sagittarius rises at 8:17 PM, highest at 12:AM, 7th magnitude, 0.6 arc-seconds, 5° high at 9 PM, at midnight it lies 17° high and sets at 4:13 AM.

Saturn appears in southern Aquarius rising at 10:56 PM, 1st magnitude, 18 arc-seconds, and 40° high at 4 AM. Neptune, 10° behind in Pisces, glowing with 8th magnitude, 2 arc-seconds, rises at 11:16 PM and 42° high. Eastern Taurus houses Mars, Uranus and Jupiter. Red planet Mars at 1:49 AM, shines with 0 magnitude, 5 arc-seconds and 25° high. Uranus lies 1° from Mars; both can be observed in a single telescope eyepiece or binoculars. Uranus rises at 1:35 AM, 5th magnitude, 3 arc-seconds and also 25° high. Finally, Giant Jupiter flares with minus 2nd magnitude, 34 arc-seconds and 15° high. All these planets set during daytime and appear either ‘full’ or close to it.

At nightfall, Scorpius lies due South and obvious to a sky watcher. Scorpius is one of the oldest constellations; its origins lie in the sands of Babylon. Star names betray its history. Sumerians and Babylonians gave us the Zodiac and named them in their languages.

Antares is the name for the red star that marks the Scorpion’s heart. ‘Antares’ means ‘rival of Ares’ the Greek version for the Roman god Mars. The two do look alike; two stars on either side of Antares were called ‘Al Niyat’ Arabic for ‘the Arteries.’ Stars in the head, were called Graffias, Deschubba and Jabbah. The stinger’ s stars are Shaula and Lesath – again Arabic names. Stars that form the tail are called by Sumerian names: Girtab and Sargas.

Clear Skies Joe Slomka