24 hour moon

A 24 hour moon (also called a continuous polar moon) is the lunar cousin of the midnight sun: at high latitude, when the Moon's declination allows it, the Moon can stay above the horizon for about half a lunar month — roughly fourteen days — while its phase changes and it circles the sky. At the geographic South Pole that means one long, unbroken stretch of moon visibility rather than a daily rise and set.

The Final Experiment later filmed the better-known 24-hour Antarctic sun. This page is about an earlier polar-sky record: a 2016 South Pole moon timelapse, not TFE footage.

Robert Schwarz, South Pole 2016

In March–April 2016, photographer Robert Schwarz recorded a fourteen-day moon timelapse at Amundsen–Scott South Pole Station (the geographic South Pole). He published the result on Vimeo as changing phase - the moon over the South Pole on 14 April 2016.

His field blog tracks the same run:

• 2016-03-09 — project starting around sunset: a two-week moon phase-change timelapse, with an Arduino stepper planned for the mount.
• 2016-03-28 — sun gone; refraction still seen the night before.
• 2016-04-14 — full write-up of the completed fourteen-day run (same substance as the Vimeo description) — upload day.
• Moonrise and moonset calendar for South Pole, March 2016 (timeanddate.com)

The filming window can be pinned from those sources rather than left as a vague late-March / early-April span. timeanddate's South Pole moonrise calendar for March 2016 places a moonrise around 23–24 March. The 28 March blog note that the sun was already gone coincides with the video opening on a quite bright sky that then darkens — sunset into the prolonged polar-night stretch — which confirms which moonrise he filmed: the rise beginning 2016-03-24 and running through 2016-04-06, not an earlier continuous-up period. The later blog write-up and Vimeo upload on 2016-04-14 document the completed fourteen-day run after it finished.

Setup, from his own description of the completed run:

• Arduino stepper on an old tracking mount
• Continuous operation around −60 °C; heated camera and lens; vacuum-oven dried gear
• 70 mm lens (~22.5° horizontal FOV); Moon's maximum elevation about 18.5°; highest moon cut off in frame
• Weather imperfect; mount stuck on cables twice and needed a daily rewind
• Phase changes while the Moon circles the horizon relative to the Sun; Moon is about fourteen days above (and below) the horizon at the Pole

Primary sources: the Vimeo upload and the South Pole 2016 blog.

Why it matters

Continuous polar moon visibility is expected on a globe at high latitude when the Moon's declination puts it in the sky for that long. It is the lunar version of the midnight sun, not a mystery. Some flat-earthers treat a "24-hour moon" as a globe-killer (see e.g. mentions on ShandTV); a South Pole timelapse of the Moon changing phase while it stays up for half a month is what the globe already predicts.

See also

• The Final Experiment
• Antarctica video compilation
• ShandTV