When the “Full Cold Moon” rises on Sunday night (Dec. 3). It will also be the first (and last) “supermoon” of 2017.
Supermoons happen when a full moon approximately coincides with the moon’s perigee, or a point in its orbit at which it is closest to Earth. This makes the moon appear up to 14 percent larger and 30 percent brighter than usual.
The moon becomes totally full at 10:47 a.m. EST (1547 GMT) on Sunday (Dec. 3). It will officially reach perigee the next day (Dec. 4) at 3:45 a.m. EST (0845 GMT), when it is 222,135 miles (357,492 kilometers) away from Earth.