LOS ANGELES (CBS) — There’s going to be a party in the sky on Cinco de Mayo.
Thanks to a phenomenon not yet fully understood by scientists, the moon will appear as a gigantic orb on Saturday night as it makes its way across the evening sky.
The so-called “supermoon” will make its appearance above the Southland at shortly before 9:00 p.m., when the moon will officially become full as well make its closest approach to Earth in 18 years at roughly 221,800 miles away.
At its peak, the moon will appear up to 30 percent brighter and 14 percent bigger than the dullest moons.
The last time the phenomenon occurred was back in March of 2011 when the moon was about 240 miles closer to Earth than it will be during this year’s approach.
Dr. Ed Krupp, the longtime director of the Griffith Observatory, told KNX 1070 NEWSRADIO that despite the celestial rarity, most skywatchers will be unable to distinguish the sight from a regular full moon.
“It is a little closer, it is a little brighter, but the eye is really not able to detect the difference,” said Krupp.
Krupp said what will undoubtedly be the largest full moon of 2012 is also an illusion.
“Our eyes and brain, for reasons unknown, are wired to make angles bigger at the horizon, so everybody knows that the moon looks huge at the horizon and not when it’s higher, but if you actually measure that with instruments, it’s actually always the same,” he said.
In addition to the “supermoon”, the Aquarid meteor shower — which occurs every spring when Earth passes through the debris field left in the wake of Halley’s Comet — will make its biggest show on Saturday night and into Sunday morning.
Krupp, however, predicted that the moon might be so bright it could wash out the meteor shower.
“It’s going to be very difficult to see meteors even if you’re somewhere out far from the city lights,” he said.