The skies will light up Tuesday night with a double lunar phenomenon: the Harvest supermoon and a partial lunar eclipse.
Supermoons are full moons that appear larger because they happen in tandem with the lunar orbit’s closest approach to earth.
According to NASA, that means the moon looks 30% brighter and 14% larger than times when the moon is as its faintest.
Tuesday supermoon is dubbed the Harvest supermoon because it’s the full moon that appears closest to the fall equinox. The name goes back hundreds of years, when farmers would sometimes use the moon’s light to work later in the evening.
But bright skies are not the only sight viewers may notice.
The full moon — the second in four consecutive months of supermoons — coincides with a partial lunar eclipse. Those happen when the Earth passes between the sun and the moon and casts a shadow on the moon.
In this case, about 3.5% of the moon will appear darkened by the Earth’s umbra, a term that describes the darkest segment of the earth’s shadow.
Unlike the solar eclipse in April, no special glasses are necessary to safely look at this eclipse.
In Southern California, the moon will rise at 6:52 p.m. The Earth’s biggest bite will appear at 7:44 p.m. and gradually dissipate over 31 minutes. By 9:48 p.m., the moon will be at its brightest.
Tuesday’s moon follows the Aug. 19 super blue moon. The phrase does not describe the color of the moon; instead, it refers to the second full moon occurring in one calendar month.
Experts tend to consider supermoons as those that fall within 90% of the moon’s closest approach to earth.
The August supermoon was about 224,000 miles from Earth. This month’s is a little closer: 222,000 miles away.
The next supermoons are Oct. 17 and Nov. 15.