Once again, the temperature dropped overnight to near -30, clearing up the sky and revealing a trace of light on the horizon, as well as the waning crescent moon in conjunction with Venus, Jupiter, and Mars. This photo was taken on the drive to the lab this morning.
On the subject of the moon, it does some very interesting things when you’re this close to the pole. Whereas in warmer latitudes it rises and sets each day, chasing the sun across the sky, up here it follows an entirely different pattern: it rises for two weeks at a time, and then sets for the following two weeks. During the time that it’s up, it travels about 347 degrees clockwise around the horizon each day.
Additionally, only certain phases of the moon are visible at any given time of year. At the winter solstice, it will rise waxing, stay above the horizon through full, and set waning. In the summer the reverse is true: the moon rises at the last quarter and sets at the first quarter, which, combined with the sunlight, makes it particularly difficult to spot. (Though not impossible!)
This is difficult to picture at first, but remember that the phase of the moon is linked to its position relative to the Earth and the sun. The moon is full when it sits behind the Earth, so that it reflects the light of the sun back at us. So if the sun is below the horizon, the full moon must be above the horizon. In contrast, a new moon occurs when it sits between the Earth and the sun. (A solar eclipse is that rare occasion when it passes exactly between the two.) So, if the sun is below the horizon, the new moon will be as well.
This has the advantage of giving us plenty of moonlight in the winter, and hopefully will make for some great photography as well, once the clouds are consistently gone!