{"id":937,"date":"2023-07-01T01:31:19","date_gmt":"2023-07-01T01:31:19","guid":{"rendered":"http:\/\/www.skycaramba.com\/monthly\/?p=937"},"modified":"2023-07-01T01:31:19","modified_gmt":"2023-07-01T01:31:19","slug":"july-2023","status":"publish","type":"post","link":"https:\/\/www.skycaramba.com\/monthly\/july-2023\/","title":{"rendered":"July 2023"},"content":{"rendered":"\n

The first of four\nso-called supermoons in a row is this month. On July 3, full moon\nwill be at 11:39 Universal Time at a distance of 361,926 kilometers\nbetween the center of the earth and the center of the moon. The\nAugust 1 full moon will be closer at 357,510 kilometers. The August\n31 full moon will be even closer at 357,356 kilometers. And the\nSeptember 29 full moon will be farther at 361,658 kilometers. Compare\nthose numbers to lunar apogee which exceeds 400,000 kilometers.<\/p>\n\n\n\n

Having\na close full moon means it will look a little bigger and a little\nbrighter than average. Since this month’s full moon is also on the\nsame day as southern lunistice, it will seem especially close and\nbright to southern hemisphere sky watchers. The lunistice declination\non the 3rd<\/sup>\nis 27.8\u00b0 south. The actual lunar perigee is the next day at 360,100\nkilometers.<\/p>\n\n\n\n

During\nthe month, the moon crosses the equator going north on the 9th<\/sup>.\nFirst quarter is on the 10th<\/sup>.\nNorthern lunistice is on the 16th<\/sup>\nat 27.9\u00b0 north. That’s the day before new moon. It’s at apogee on\nthe 20th<\/sup>\nat 406,300 kilometers away. It’s crossing the equator going south on\nthe 23rd<\/sup>.\nA second southern lunistice happens this month on the 30th<\/sup>\nat 27.9\u00b0 south. All dates mentioned here are in Universal Time.<\/p>\n\n\n\n

As it\nmakes its way around the sky, the moon will pass Antares on the 1st<\/sup>.\nIt passes Pluto on the 4th<\/sup>.\nNote where the moon is on that night, and you can remember where\nPluto is all month. You’ll need a very high end telescope and a very\ndark sky to see Pluto. For most of us, knowing where Pluto is, is\ngood just for trying to impress our friends.<\/p>\n\n\n\n

\"Saturn<\/figure>\n\n\n\n

The\nmoon passes Saturn on the 7th<\/sup>,\nthen Jupiter in the morning sky on the 11th<\/sup>,\nand Uranus on the 12th<\/sup>.\nIn the evening sky, the moon’s near Mercury on the 19th<\/sup>,\nVenus on the 20th<\/sup>,\nand Mars on the 21st<\/sup>.\nThat’s going to be a fine few nights for planet watching. On the\n25th<\/sup>,\na first quarter moon passes Spica. Then it’s near Antares on the\n28th<\/sup>.<\/p>\n\n\n\n

\"The<\/figure>\n\n\n\n
\"Finder<\/figure>\n\n\n\n

Tides<\/strong><\/p>\n\n\n\n

These close full\nmoons will have an effect along ocean coastlines around the world.\nTides can be very high when the moon’s full and close. And in many\nplaces, when high tide is very high, low tide is very low. People\ngenerally understand that the moon has something to do with the\ntides. But the most common idea of how tides work isn’t correct.<\/p>\n\n\n\n

Maybe for you, it\nstarted in grade school when a teacher explained that the moon’s\ngravity pulls on Earth’s water and causes the tides. That’s a partial\nexplanation. It leaves out the rest of what’s happening and gives the\nimpression that the moon’s gravity is very selective, somehow not\npulling on anything else, and pulling only on the water that’s in the\nocean. Think about it. The tides barely affect huge lakes and you\ndon’t notice any tidal effect in a swimming pool or a sinkful of\ndishwater you forgot to drain. Plus, most places with tides have high\ntide twice a day. The moon’s closest to any point on Earth just once\na day. There’s more going on.<\/p>\n\n\n\n

The moon’s gravity\nis actually pulling on everything on Earth. That’s how gravity works.\nIf something has mass or energy, it’s affected by gravity. Even light\nbeams follow curved paths around black holes because the gravity’s\nthat strong. As the moon goes around the earth, it tugs on its parent\nplanet. The earth has more mass and tugs back. The result is like\nwhen a big, strong adult and a small child pull on a rope in\ntug-of-war. The adult’s harder to move and the child goes along with\nthe tugs. So, the moon goes around the earth.<\/p>\n\n\n\n

That’s not to say\nthe moon’s gravitational pull on Earth is inconsequential. Earth\nactually is nudged a little by the moon. And that’s what causes the\ntides. It’s comparable to having glass of water and moving it back\nand forth on the tabletop. The water sloshes back and forth, getting\nhigh on one side of the glass and low on the other. You’re moving the\nglass and the water together, but the glass and the water get out of\nsync because the glass isn’t fluid. On Earth, land masses aren’t\nfluid but water is, so the oceans get sloshed around in tides.<\/p>\n\n\n\n

You don’t see the\nsame effect in swimming pools and sinks, because the containers are\ntoo small. The change in force is applied more quickly throughout the\ncontainer and the liquid, negating any tidal effect. Same thing with\nthe Coriolis effect, which makes ocean currents curve but some people\nwrongly think has something to do with which way the water swirls\nwhen they flush the toilet.<\/p>\n\n\n\n

Other events<\/strong><\/p>\n\n\n\n

\"Mars<\/figure>\n\n\n\n

Mercury\nstarts July at superior conjunction. You’ll have a good chance to\nspot it in the evening sky on the 19th<\/sup>\nwhen a thin, crescent moon is 3.3\u00b0 away. The planet gets as close as\n5.1\u00b0 away from Venus on the 27th<\/sup>.<\/p>\n\n\n\n

\"Mars,<\/figure>\n\n\n\n
\"Mars,<\/figure>\n\n\n\n

Venus\nand Mars are 3.9\u00b0 from each other on the 1st<\/sup>.\nVenus has been following Mars through Gemini and Cancer for a few\nmonths now, even traipsing through the Beehive Cluster on a trek\ntoward Leo. But Venus was at greatest elongation last month. It’s\nsoon to head sunward. It will make it to the heart of the lion on the\n16th<\/sup>,\n3.5\u00b0 from Regulus. This month’s Venus-moon conjunction won’t be a\nvery close one. The two are 7.3\u00b0 apart on the 20th<\/sup>.<\/p>\n\n\n\n

\"Mars<\/figure>\n\n\n\n

Mars\nis traveling through Leo. The moon is 3.0\u00b0 from the red planet on\nthe 21st<\/sup>.\nThe planet’s northern solstice is on the 12th<\/sup>.\nThat’s the equivalent of Earth’s June solstice.<\/p>\n\n\n\n

\n