For live links, click to: riverhouses.org/2019-moon-phases
There will be a lovely gibbous moon high up in the southern sky this evening. Can your homeschool students recognize the phases of the moon? Why not teach them the lunar cycle during this momentous month when we are remembering the 50th anniversary of the first moon landing.
Did you know there’s an emoji symbol for each phase of the moon? It’s true! Whenever we’re posting about the moon here at the River Houses we try to use the correct emoji, and you can do the same, illustrating the moon’s phases for your students, quizzing them with emojis, and inviting them to recite the northern-hemisphere formula, “fills in from the right, drains out to the left”:
🌑 NEW
🌒 WAXING CRESCENT
🌓 FIRST QUARTER
🌔 WAXING GIBBOUS ← tonight
🌕 FULL (second quarter)
🌖 WANING GIBBOUS
🌗 THIRD QUARTER
🌘 WANING CRESCENT
🌑 NEW (again)
A complete cycle, from new to new, is one (lunar) month — 29 days — and the word month and moon are in fact cognate words, having the same historical origin. (Compare the expression, “many moons ago,” meaning, “many months ago.”)
The time from one quarter to the next — from new to first quarter, from first quarter to full (second quarter), from full to third quarter, or from third quarter to new again — is about seven days, and that’s the basis for the week, which is a quarter of a month: four quarters in one “moon,” four weeks in one month. (This also explains why lunar terminology is sometimes confusing to beginners: the first and third “quarter” moons are half full, because “quarter” doesn’t refer to appearance but rather to a given point within the monthly lunar cycle.)
What celestial observations will you and your students be making in your homeschool this lunar month? 😊
❡ Crescent and gibbous and waxing and waning: The word crescent is common in English in many contexts, but the word gibbous — convex, bulging, humped, hunchbacked — is much less common and is rarely used today to describe anything other than the moon, which is a shame because it’s a wonderful word. Similarly, waxing (growing, increasing) and waning (shrinking, decreasing) are used most often now as paired terms in the context of the moon, but they do still survive in a few other contexts (to wax poetic; his interest waned). 🌔 🌘
❡ Watchers of the skies: This is one of our regular Homeschool Astronomy posts. Add your name to our River Houses mailing list (riverhouses.org/newsletter) and get great homeschool teaching ideas delivered right to your mailbox every week. 😊
