Moon is close, bright tonight

With Jennifer's email as our guide, tonight we probed the night sky over Tucson. The moon is never any bigger than it is tonight, and that's Mars over to the left at the tip of the cloud bank. It is perfectly round (see inset at right) and, as advertised, red. The clouds provided some drama tonight. We took these pictures at about 7 p.m., just after sunset. Here's the information Jennifer sent us.

Tonight's full moon will be the biggest and brightest full moon of the year. It offers anyone with clear skies an opportunity to identify easy-to-see features on the moon.

This being the first full moon of 2010, it is also known as the wolf moon, a moniker dating back to Native American culture and the notion that hungry wolves howled at the full moon on cold winter nights. Each month brings another full moon name.

But why will this moon be bigger than others? Here's how the moon works:

The moon is, on average, 238,855 miles (384,400 km) from Earth. The moon's orbit around Earth – which causes it to go through all its phases once every 29.5 days – is not a perfect circle, but rather an ellipse. One side of the orbit is 31,070 miles (50,000 km) closer than the other.

So in each orbit, the moon reaches this closest point to us, called perigee. Once or twice a year, perigee coincides with a full moon, as it will tonight, making the moon bigger and brighter than any other full moonsduring the year.

Tonight it will be about 14 percent wider and 30 percent brighter than lesser full Moons of the year, according to Spaceweather.com.

As a bonus, Mars will be just to the left of the moon tonight. Look for the reddish, star-like object.