Skywatchers eager to witness a rare celestial phenomenon will be in for a treat Saturday night with the appearance of an especially big and bright moon known as a "supermoon."

At 8:35 p.m., the orbiting satellite will reach its lunar perigee, meaning it will be closer to Earth than at any other time during the year. Two minutes after the moon will also become full.

For Earthlings, Cameron Cronin of the H.R. MacMillan Space Centre in Vancouver says the serendipitous conditions can result in the moon looking up to 14 per cent bigger and 25 per cent brighter.

"It's going to be beautiful," Cronin told ctvbc.ca. "It's sort of the perfect storm of… when the full moon is and how the sun is going to hit it. So it is going to be in prime location for being nice and bright."

The moon will be 356,953 kilometres away from the Earth Saturday night, according to the Lunar Perigee and Apogee Calculator website linked to by NASA.

On May 19, the moon will arrive at its furthest distance from Earth, its apogee, when it will be situated 406,450 kilometres away.

The last supermoon took place on March 19, 2011.

Astrologer Richard Nolle, who coined the term "supermoon" in 1979, explains more precisely that it occurs when the Earth's satellite is full and travels within 90 per cent of its closest approach to our planet within a given orbit.

"In short, Earth, Moon and Sun are all in a line, with Moon in its nearest approach to Earth," Nolle wrote in a blog.

But Cronin warns the difference in the size of the moon might be difficult to perceive, from a human perspective.

"It's a gradual thing. I mean every month there's a bit of a variation between the distance between the Earth and the moon," he said. "It kind of creeps up slowly."

Poor weather conditions could also put stargazers out of luck. However, if the night sky is clear the H.R. MacMillan Space Centre will welcome guests to view the supermoon through its half-metre telescope between 8 p.m. and midnight by sending out a tweet from @askanastronomer. Two astronomers will also be at the observatory to chat about the wonders of space.

Moon lovers can also simply use the naked eye to take in the spectacular sight if clouds stay away.

"We're lucky in the sense that the moon is going to be very, very bright, so you can really see it from anywhere," Cronin added.

According to Space.com, Saturday's moon will rise around sunset and rest visible in the sky until sunrise. This is the only time in May when the moon will hang in the sky all night without being seen during daylight hours.

Cronin says that while the supermoon will have a marginal, likely-unnoticeable influence on the tides, superstitions regarding its more extreme geological effects are bogus.

"I really wouldn't hold much water in the stories that go around and say that there are more earthquakes, more natural disasters or any of that," he said. "There isn't any empirical, hard evidence that says a supermoon has any influence over those."

For photographers trying to snap their own dramatic shots of the celestial spectacle, Jeff Gin of Leo's Camera Supply advises them to watch their settings.

"It's the opposite of what you would think for taking pictures at nighttime," Gin said.

He says using daytime settings and a flash will result in the best photos.

"Turn the flash on, which is not using the flash to illuminate the moon, but the camera will choose a faster shutter speed, which will help get the correct exposure to get the details of the moon," he said.

To capture the full impact of the supermoon, BCIT astronomy instructor Bill Bernyeat suggests catching it just as it rises at 8:35 p.m.

"The moon gives the impression of being bigger when it's on the horizon and littler when it's way up high in the sky," Bernyeat said.

With files from CTVNews.ca and CTV British Columbia's Penny Dalfos