Make sure to look up on Sunday night to catch the only supermoon of 2017.
The moon will become totally full at about 7:47 a.m. local time on Sunday and will officially reach perigee (the closest point in its orbit to the earth) on Dec. 4 at 12:45 a.m. local time, when it will be 222,135 miles away from Earth, according to space.com.
Supermoons happen when a full moon approximately coincides with the moon’s perigee, making it appear up to 14 percent larger and 30 percent brighter than normal, according to space.com.
The perigee for this supermoon isn’t the closest of the year; that happened on May 25, when the moon was 221,958 miles away from Earth. But since the date didn’t coincide with a full moon, it didn’t qualify as a supermoon.
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Not only will the moon appear brighter and larger, but we will also see some of the biggest tides of the year (king tides).
Tides are enhanced when Earth is at perihelion (the closest point in its orbit to the sun) and the moon is at perigee, according to PG&E meteorologist John Lindsey. The gravitational forces exerted by the moon and sun are at their greatest at this time.
This tugging produces a tidal “bulge,” or area of higher sea level on the ocean’s surface.
On Dec. 4, the high tide will reach 6.8 feet at 9:30 a.m. at Port San Luis. Later in the day, the low tide will drop to -1.5 feet.
Tribune staff contributed to this report.