Harvest Moon will shine brightly Monday night

A passenger aircraft descends towards Heathrow Airport with a full moon seen behind, in west London, Sept. 8. The September full moon, also known as the Harvest Moon, is the last of this summer's three "supermoons." (REUTERS/Toby Melville)

When you look up at the sky tonight, you will likely catch the full Harvest Moon. At 9:38 p.m. EST, the final of the three back-to-back “supermoons” will light up the sky for the Northern Hemisphere, according to NASA (via Discovery.com). While the name associates it with the fall, this Harvest Moon is actually the final full moon of the summer. The last two “supermoons” of the season – one in July and the other in August — fell during the moon’s perigee, which marks when it was closest to the Earth in its orbit.

According to NASA, full moons can vary in size due to the oval shape of a moon’s orbit. The moon follows along an elliptical path around the planet with one side, its perigee, leaning about 31 miles closer than its other side, the apogee.

This won’t be the largest of the season’s three supermoons – the full moon from Aug. 10 holds that honor. Nevertheless, the Harvest Moon will be an impressive sight. While it appears during the dog days of summer, the Harvest Moon hints at the coming fall season due to its reddish, pumpkin-like appearance. The distinct coloration is the result of the moon rising just as the sun sets, reports The Huffington Post.

Many supermoon watchers believe that the Harvest Moon stays in the night’s sky much longer than other full moons. In reality, the Harvest Moon rises slightly later each night. This in turn provides farmers trying to reap crops well into the evening during the last gasp of late-summer daylight, with some extra light, according to Discovery.com.