How to view the supermoon that's also a blue moon on Long Island

 A supermoon — a moon that appears larger and brighter than an ordinary full moon — will be visible this week through the early hours of Wednesday morning.

A supermoon appears when the moon is full and reaches perigee — that is, the part of its monthly orbit that swings closest to Earth.

The moon will be officially full on Monday afternoon, at 2:26 p.m. EDT (though viewers will, of course, get a better look after dark) and it will appear full or near full from Sunday through early Wednesday, according to NASA.

This is the first supermoon of the year; there will be three more, in September, October and November.

A supermoon "doesn’t look much different to the human eye," cautions Ken Spencer, president of the Astronomical Society of Long Island. It’s more noticeable if you compare photos taken at perigee and at the moon’s apogee — when it is farthest from the Earth.

To get the best effect, viewers should find a spot with "a good eastern horizon and watch the moon coming up," Spencer suggested, because the moon generally looks larger when it’s closest to the horizon. "It’ll be more impressive." With binoculars, Spencer added, "it makes the scene even more sublime."

The moon will be rising a little after 8 p.m. Monday from about 10 degrees south of east. "On the South Shore beaches of Long Island, that means you can watch the moon rise out of the Atlantic Ocean," Spencer noted. 

The moon will rise at about 8:30 Tuesday night.

Long Islanders can see the supermoon anywhere there is an unobstructed view of the sky, as long as there is little or no cloud cover. You don’t necessarily have to seek out a place away from streetlights. "You don’t have to worry about light pollution with the moon," Spencer said. "The moon is so bright."

This week’s supermoon will also be a blue moon: the third of four full moons this summer. (The origins of the term "blue moon" are unclear, but it does not mean that the moon appears blue.) Ordinarily there is one full moon each month but, occasionally, if there’s a full moon at the very start and the very end of a month, there can be two in a month or four in a season. Blue moons occur roughly once every 33 months — and thus, the phrase "once in a blue moon."

 If anything, this blue moon will appear red, said Jason Cousins, president of the Amateur Observers’ Society of New York. Particulate matter from wildfires burning in California and Canada has drifted to the region, which gives the sun and moon a reddish glow. Cousins said it surprises people that smoke from hundreds of miles away can alter the view of celestial objects hundreds of thousands and even millions of miles away. "But it shows you how we are all connected," he said. "We are all global passengers."