HARVEST MOON 2019
Moonrise: 6:49 PM EST
Background:
During the year, the sun is furthest north of the equator on the first day of northern summer and its furthest south of the equator on the first day of northern winter. Right now we’re at the beginning of fall in the northern hemisphere. The moon, opposite the sun, is moving northward as the sun is moving southward. Credit: phys.org
Why is the September full moon called the Harvest Moon?
In rural times, farmers worked mostly by the light of the sun. In September, when days get shorter, the full moon provided light so farmers had more time to harvest crops which were ready to be picked!
Why does the full moon look so much bigger as it rises near the horizon?
There are many theories about why this happens. Ultimately, it is an optical illusion. The moon does not really change size as it rises. Most recently, it is thought that when the moon is low to the horizon, we can visually compare it to objects around us. That makes our brain perceive it looks bigger when down low, compared to trees, houses, hills, etc.
Why does a Harvest Moon look orange when low to the horizon?
This has to do with color science. Some colors have shorter wavelengths (blue), while others have longer wavelengths (red). The earth’s atmosphere is filled with tiny particles, especially lower to the ground, where the atmosphere is thicker. The longer red wavelengths are more visible when the light of the moon shines through the lower, thicker part of the atmosphere!
Here’s a quick activity from DK Books that you can do at home explaining this concept: https://youtu.be/4Kf_ULtmxuQ
*Photo Credit: Phys.org