BOSTON (CBS) – What’s that in the sky…a bird…a plane…No, it’s Supermoon! Or at least that is what some scientist are calling this weekends full “worm” moon.
On Saturday afternoon at 3 p.m. the moon will be at perigee, marking its closest pass to the Earth in 2011: a mere 221,565 miles away. Just 50 minutes earlier, the moon will have been officially full. It is a rare combination that happens only once every 20 years or so.
The last time we saw a moon this large was way back in March of 1993. If you miss it this year, you will have to wait until the year 2029 to see it again!
Related: Moon Phases & Sunset Times
The full moon this weekend will be about 14 percent bigger and 30 percent brighter than lesser moons this year.
When the moon rises in the east on Saturday at 7:15 p.m. (just after sunset), it will appear to be gigantic because of something known as the “moon illusion”. This is when a low-hanging moon looks incredibly large as it hovers in back of objects such as trees and buildings.
Saturday’s moon being so close to Earth will only make this illusion greater!
The perigee moon will also cause extremely high tides for a few days. The highest tides typically lag a few days behind the full moon and that will be the case this year. High tides on Monday and Tuesday in Boston Harbor will range between 11 and just over 12 feet, peaking at 1:31a.m. on Tuesday morning at 12.2 feet.
If we were to have a coastal storm during this period, we could be in for some serious coastal flooding; thankfully that is not the case.