July stargazing: Buck Moon, Lāhainā Noon, and meteorites (soon)

July could look like thin choices for the stars, after all, the most interesting celestial phenomenon of the month does not even occur at night (or at all in most regions of the world)! However, the night types of patients will be rewarded twice towards the end of this month, as the old adage says: good things come to those waiting.

July 10: Full Buck Moon

The full moon of July is The Buck Moon, a name that comes from the fact that the middle of summer finds male deer in their largest and most impressive for the year. If you didn’t know, Deer has lost its woods every year! It reaches peak lighting on July 10 at 4:30 p.m. Hae, so be sure to catch it once the sun sets and the moon.

The alternative names for the full moon in July include several nicknames on the theme of horticulture: the moon of blueberry and the raspberry moon (both from Anishinaabomowin), the corn in the moon of Tassel (Cherokee) and the moon of strict beans (Ohyotsheli). Both at the tunic and Seneca, on the other hand, the moon of this month is the little sister of the summer moon, a reference to the fact that the Moon of June is the summer moon proper.

July 15: Lāhainā Midi # 2 for 2025

We discussed the phenomenon known in Hawaii under the name of Lāhainā noon in May. Lāhainā noon takes place when the sun is directly above, resulting in a rather disconcerting shadows. The phenomenon only occurs in the tropics, and only for two short periods per year. On July 15 marked the arrival in Honolulu of the second and last Lāhainā Midi for 2025.

The time and date vary on the exact location; According to Love Big Island, if you are in Hawai’i, your shadow will disappear for a few minutes at the following hours:

Honolulu (O’hu): 12:37 p.m. (July 15)

Kahului (MAUI): 12 h 32 (July 17 and 18)

Līhuʻe (Kauai): 12:43 p.m. (July 11)

Hilo: 12:26 p.m. (July 23 and 24)

Kona: 12:30 p.m. (July 24)

Interestingly, this solar phenomenon was used in what could be the first measure of the circumference of the earth. In the 3rd century BCE, the mathematician, the polymathe and the Erastosthene – Greek goalkeeper of the famous Library of Alexandria – learned that while the Lāhaina Midi was performing in Syene, where the sun shone directly at the bottom of a well at noon, it was not observed in Alexandria.

Erastosthene realized that if he assumed that the sun’s rays were parallel, the absence of a shadow in synène could be explained by the curvature of the earth. He also realized that if he erects a post of a length known in Alexandria and measured the length of the shadow he projects, he could build a straight triangle with the two short sides being the post and the shadow. The resulting triangle would be similar to that where the two short sides were the radius of the earth and the distance between synène and Alexandria. If he measured the opposite angle of the smallest triangle, he would know the same angle on the large triangle.

He measured an angle of around 7 ° and concluded that the distance between the Syene and the Alexandria was around 1/50 (that is to say 7 ° / 360 °) of the circumference of the earth. Its resulting calculation has put the circumference of the earth in one place between 24,000 and 25,000 miles – it is very close to the modern measure of 24,901 miles.

July 20 and 21: the crescent moon against the pleiads

While very little of the moon is lit because it decreases to finish the darkness, the rest of the disc is still there. The resulting light can create its own unexpected celestial phenomena. A good example comes towards the end of this month, because the crescent moon passes directly on the Pléiades cluster. According to the sky of the earth, this will lead the stars of the Pleiades seeming to disappear one by one, then reappears when the moon passes. To enjoy the show, look at the east about an hour before dawn.

July 30: the aquarids delta reach their peak

At the end of July and early August will be a treat for meteorite enthusiasts. There are the famous Perseids, which we will discuss next month, but the Delta Aquarids are underway. This meteor shower will start on July 18, continuing throughout July and early August. The Delta Aquarids come from the 96p / Machholz comet, which is dangerously closer to the sun at its closest approach, and has a chemical composition which is almost unique among the known comets. (Also: if you are wondering how meteor showers relate to the comets, we are covered to you.)

To observe the Delta aquariids, look south to the brilliant star Fomalhaut. The “radiant point” of meteorites or the original point is just above this star. The shower should culminate around 2 am, local time on July 30. It is a lot of cosmic and fun knowledge for July. Whatever you turn, you will get the best experience if you are moving away from light pollution sources – and you make sure to consult our star advice before leaving in the night.

Until next month!

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