Super viewing forecast for supermoon

IOWA CITY - Before the sun rises Monday, University of Iowa astronomy professor Steven Spangler plans to be standing in his backyard with his eyes skyward.

'It's always worth going out and seeing these things,” Spangler said of this month's supermoon, which occurs when the moon reaches its full phase at the closest point to Earth along its elliptical orbit.

Because that egg-shaped orbit 'breathes,” Spangler said, meaning it 'fluctuates in and out,” experts say Monday's supermoon could be called a 'super supermoon” in that it is to be full at its closest orbital point to Earth since 1948, according to Space.com.

The moon is to reach that nearest point - 356,509 kilometers from Earth - at 5:23 a.m. Monday in Iowa. It is to crest at full at 7:52 a.m. central time, after moonset, meaning the best viewing opportunity happens predawn, Spangler said.

And, for those who don't want to wake up early on a Monday, Spangler said before bed should work just fine.

'Sunday is going to be close enough,” he said.

The National Weather Service is forecasting party cloudy skies late Sunday and mostly clear views Monday morning.

The moon won't be as close and bright again for another 18 years, but Spangler warns against expectations for a massive swollen globe.

In fact, UI physics and astronomy professor Jasper Halekas said if the moon were pie in the sky, you might only get one extra bite Monday.

Quoting American astrophysicist Neil deGrasse Tyson, Halekas said, 'I don't know who first called it a supermoon. If you have a 16-inch pizza, would you call that a super pizza compared with a 15-inch pizza?”

Supermoon facts

Best

viewing is around 5:30 a.m. Monday in Iowa, when the nearly-full moon is closest to Earth since 1948.

Weather

models predict partly cloudy to mostly clear skies late Sunday into early Monday.

Supermoons

can be up to 14 percent bigger and 30 percent brighter than full moons at their farthest distance from Earth. However, telling the difference is not always easy.

Tides, for those near oceans, are to be a little higher. That's because the gravitational pulls of the moon and sun, when both aligned with the Earth, act in concert. The next

full moon expected to appear this big won't occur until Nov. 25, 2034.