According to Space.com, a supermoon happens when the full moon coincides with the moon's closest approach to earth in its orbit. This makes the moon appear up to 14 percent larger and 30 percent brighter than usual.
The first and last supermoon of 2017 will occur on December 3. The December full moon is known as the Full Cold Moon. It becomes totally full at 10:47 a.m. on Sunday, December 3. It will reach perigee (the point in its elliptical orbit when its closest to Earth) at 3:45 a.m. on December 4. The moon will rise at 5:13 p.m. in Baltimore/Annapolis on December 3, with the sun setting at 4:43 p.m.
The best time to watch a supermoon is often when it's low, near the horizon, just after the moon rises. So if you can get outside (or on the water!) around sunset on December 3, you should be able to catch a good show. Make sure to check the weather forecast this weekend. If overcast skies are expected on the night of the supermoon, you can still get a good view the night before and after. The moon won't be quite as full those nights but it will still look larger and brighter than usual.
Hoping to photograph this weekend's supermoon? CNET offers these tips. Find the full list at How to Photograph the Supermoon.
- Switch out of automatic mode.
- Set your ISO sensitivity to a low level, such as 100 or 200.
- The sharpest results will be achieved when using a narrower aperature, upwards of f/8.
- Use manual focus. Autofocus generally does not work as well in low light.
- Use a telephoto lens or long optical zoom.
- Take out any form of shake.
- A tripod is ideal. A remote shutter release or self-timer mode can also help stabilize the camera.