It almost seems as if we have a full moon night for several nights in a row. Around those full moons, there’s no long lag between moonrise one night, and moonrise the following night. That’s not the case around the full Harvest and Hunter’s Moons. So your average full moon rises at sunset, and, the next night, the moon rises 50 minutes after sunset. On average, the moon rises about 50 minutes later each day. Let’s put it in terms of actual rising times, for the moon. This minor lunar standstill acts to lessen the effect of the Hunter’s Moon. It’s a minor lunar standstill year, when the moon’s monthly travels take the moon only from about 18.5 o south to 18.5 o north of the Earth’s equator. So we have that to look forward to, in 2025. In years when a major lunar standstill is happening, it accentuates the effect of the Harvest and Hunter’s Moon. This extreme inclination is called a major lunar standstill. For instance, in the years 20, the moon in its monthly travels swings from about 28.5 o south to 28.5 o north of the Earth’s equator. The inclination of the moon’s orbital path to the plane of the Earth’s equator changes over a cycle of 18.6 years. The inclination of the moon’s orbit is why our moon – as it rises and sets each day – spends about two weeks rising and setting south of due east and west, and then two weeks rising and setting north of due east and west. Thereby, the lunar standstill points are 5 o closer to the equator than the solstice points are (23.5 o – 5 o = 18.5 o declination). In a year when the moon’s orbit intersects the ecliptic at the March equinox point, going from north to south, we have a minor lunar standstill year. The plane of the moon’s orbit is inclined at 5 o to the ecliptic (plane of the Earth’s orbit). It’s this inclination that creates minor lunar standstills and the diminishing effect for Harvest and Hunter’s Moons. Thus, our moon’s orbit is quite inclined to the plane of the Earth’s equator. However, our moon orbits Earth on nearly the same plane that Earth orbits the sun (aka the plane of the ecliptic). If our moon did likewise – orbited above Earth’s equator – then the moon would always rise due east and set due west every day. Unlike Earth’s moon, many moons in our solar system orbit above the equator of their parent planets. In fact, as seen from both earthly hemispheres, it’s affecting autumn moons for several years to come. It’s affecting these two autumn moons in 2016. A hallmark of the cycle of minor lunar standstills is that it diminishes the Harvest and Hunter’s Moon effect of rising near the time of sunset for several evenings in a row. But, like many things in astronomy, the moon’s appearance in our sky follows a cycle. And, like all full moons, this one will rise around sunset. So we’ll all see a full supermoon on the nights of October 15 and 16, from all parts of the globe. If you’re in the Southern Hemisphere, everything in this article about Hunter’s Moons applies to you as well … next March. Your Hunter’s Moon will come on March 12, 2017. Meanwhile, the classic Harvest Moon and Hunter’s Moon characteristic – close-to-sunset rising times for several nights in a row – won’t be as pronounced in 2016, due to a minor lunar standstill.įor the Southern Hemisphere. So, for all of us around the globe, the upcoming full moon – which will come on the nights of October 15 and October 16 – might look a bit brighter than usual in your sky. In 2016, the Northern Hemisphere’s Hunter’s Moon is also a supermoon. The full moon immediately following the full Harvest Moon enjoys the designation of Hunter’s Moon. Depiction of minor lunar standstill outside the National Museum of the American Indian, Washington, DC, representing markings found in New Mexico’s Chaco Canyon.
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