THE SOUTHWORTH PLANETARIUM 207-780-4249 www.usm.maine.edu/planet <http://www.google.com/url?q=http%3A%2F%2Fwww.usm.maine.edu%2Fplanet&sa=D&sntz=1&usg=AFQjCNHulkHuLP13bOG2PkNrPazsGWFs2A> 70 Falmouth Street Portland, Maine 04103 43.6667° N 70.2667° W Altitude: 10 feet below sea level Founded January 1970 Julian Date: 2459402.18 2020-2021: CXLVII THE DAILY ASTRONOMER Tuesday, July 6, 2021 July 2021 Night Sky Calendar Part II *SUNDAY, JULY 11: MOON NEAR PRAESEPE:* Early this evening, one will see the thin waxing crescent moon (3% illuminated) near Praesepe, a galactic star cluster within the constellation Cancer the Crab. Cancer is one of the thirteen zodiac constellations, defined as those constellations through which the Sun appears to travel each year. As the Sun appears to "move through" Cancer in early August, this faint, inverted y-shaped constellation is currently close to the western horizon at dusk. See it and the crescent moon tonight! [image: Cancer.PNG] *MONDAY, JULY 12: MOON, VENUS AND MARS WITHIN A CIRCLE WITH A 3 1/2 DEGREE DIAMETER (SILVER EVENT!!)* Three worlds in one location! Or, to be more precise, in one apparent location. One will see the waxing crescent moon, Venus and Mars within a tight circle in the western evening sky. Observers should experience little difficulty identifying them. The crescent moon looks like, well, a crescent moon. Venus is now more than 170 times brighter than Mars! Moreover, Mars exudes a reddish color, which is currently muted due to dimness. [image: skychart.ashx.png] *TUESDAY, JULY 13: VENUS 0.47 DEGREES NNE OF MARS* Although the moon has moved on, Venus and Mars will still appear close together tonight. Venus is more than 170 times brighter than Mars (just like last night), so one can easily distinguish between them. Their close proximity is an illusion. Tonight, Venus will be 130 million miles from Earth, while Mars is approximately 223 million miles from our home world. *SATURDAY, JULY 17: FIRST QUARTER MOON* A perfect time to offer a review of the four cardinal lunar phases and their respective rise/set times, which are approximations. - *NEW MOON -* rises at sunrise; sets at sunset (i.e. isn't visible.) - *FIRST QUARTER* - rises around noon; sets around midnight - *FULL MOON* - rises around sunset; sets around sunrise - *LAST QUARTER* - rises around midnight; sets around noon *SUNDAY, JULY 18: DEPARTING LION* One must always take the atmosphere into account when viewing the night sky. Constellations are more difficult to observe near the horizon than at higher points simply because the amount of atmospheric gases separating an observer from the horizon is forty times greater that separating an observer from the point directly overhead. Altough Leo the Lion remains low in the western early evening sky this month, it is becoming more difficult to see owing to its low orientation. So, we take this opportunity to bid it farewell. [image: istockphoto-638713934-612x612.jpg] We recall that Heracles was forced to perform a series of labors for King Eurystheus in order to atone for having slain his family under the influence of Hera's insanity spell. (That Heracles had been acting under such influence was not deemed to have mitigated the crime.) During his second labor, Heracles was sent to the land of Nemea, where it was said that an invincible lion was terrorizing the populace. The King heard that the Lion was covered by an impenetrable hyde that he wanted for himself. After searching for more than a month, Heracles came upon the Lion and he was astonished to behold him, for the Lion was as large as a young dragon and as equally fierce. Heracles rapidly fired a barrage of arrows at the monster, only to see them all bounce harmlessly off the Lion. He then charged the lion with his club, only to see his club rebound off the hyde without inflicting the slightest injury. In desperation, Heracles wrestled the Lion to the ground and pushed his hands under the lion's chin. He then strangled the beast and as it lay dead, Heracles snapped off one of its claws and used it to cut away the hyde. He then ran back to Eurystheus to deliver the prize. The King then grew deeply frightened of Heracles, for his victory over the Nemean Lion was indicative of Heracles' immense power. He then commanded Heracles to never approach him again, but would instead convey all future commands through emissaries. The goddess Hera, Heracles' arch-nemesis, hoisted Leo in the sky as a tribute to it for its formidable strength. The lion adorns the firmament today. By month's end, the lion will vanish into the dusk and will return to the early morning sky in early October. Part III tomorrow. To subscribe or unsubscribe from the Daily Astronomer: https://lists.maine.edu/cgi-bin/wa?SUBED1=DAILY-ASTRONOMER&A= <https://lists.maine.edu/cgi-bin/wa?SUBED1=DAILY-ASTRONOMER&A=1>