Notes on 'Supermoons'
Dec. 26th, 2017 01:57 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
lenyberry(this is quite stream-of-consciousness, so I apologize if it skips around confusingly)
A supermoon is a full moon that falls at a time when the moon is at a closer point in its orbit to earth. The moon’s orbit is elliptical, so there’s a point at which it’s the closest it gets, and another at which it’s the farthest it gets.
The technical terms are perigee (the closest point) and apogee (the farthest point).
Incidentally, the opposite of a supermoon is called a micromoon – a full moon falling near the apogee rather than the perigee. A micromoon appears smaller and dimmer than usual.
The moon keeps this orbital pattern even when it doesn’t line up with full moons, of course. The full lunar orbit takes approximately 27.5 days from perigee to perigee, while the lunar phase cycle runs approximately 29.5 days.
Any moon phase falling at or close to the perigee is enhanced in effect and appears larger & brighter, while phases falling toward the apogee are diminished in effect and appear smaller & dimmer. It’s mostly talked about with regards to supermoons because those are the most dramatic, but a new moon or waxing crescent or last quarter moon falling at the perigee is similarly enhanced.
The moon’s speed of travel also increases at its perigee and slows at its apogee (this is true of all elliptical orbits). Times when the moon is at perigee and travelling faster are good for quick results, while times when the moon is at apogee are better for anything you want to last for a long time.
You can use timeanddate.com for tracking perigee and apogee: https://www.timeanddate.com/astronomy/moon/lunar-perigee-apogee.html
(also a good site for other timing tracking like moon phase, sunrise/sunset, moonrise/moonset, upcoming eclipses, etc)
A supermoon is a full moon that falls at a time when the moon is at a closer point in its orbit to earth. The moon’s orbit is elliptical, so there’s a point at which it’s the closest it gets, and another at which it’s the farthest it gets.
The technical terms are perigee (the closest point) and apogee (the farthest point).
Incidentally, the opposite of a supermoon is called a micromoon – a full moon falling near the apogee rather than the perigee. A micromoon appears smaller and dimmer than usual.
The moon keeps this orbital pattern even when it doesn’t line up with full moons, of course. The full lunar orbit takes approximately 27.5 days from perigee to perigee, while the lunar phase cycle runs approximately 29.5 days.
Any moon phase falling at or close to the perigee is enhanced in effect and appears larger & brighter, while phases falling toward the apogee are diminished in effect and appear smaller & dimmer. It’s mostly talked about with regards to supermoons because those are the most dramatic, but a new moon or waxing crescent or last quarter moon falling at the perigee is similarly enhanced.
The moon’s speed of travel also increases at its perigee and slows at its apogee (this is true of all elliptical orbits). Times when the moon is at perigee and travelling faster are good for quick results, while times when the moon is at apogee are better for anything you want to last for a long time.
You can use timeanddate.com for tracking perigee and apogee: https://www.timeanddate.com/astronomy/moon/lunar-perigee-apogee.html
(also a good site for other timing tracking like moon phase, sunrise/sunset, moonrise/moonset, upcoming eclipses, etc)
