BLOG: 2011 March Supermoon
By Justin Drabick
Have you looked at the moon tonight and thought that this month's full moon looks bigger than usual. Well you thought correctly.
This month's full moon occurs about one hour from perigee. This happens about every 18 years and the last time was March 1993.
What is perigee? Full Moons vary in size because of the Moon's orbit. It is shaped like an ellipse (oval) with one side (perigee) about 50,000 km closer to Earth than the other (apogee) side. Tonight, the moon is closest as it is going to get to the Earth. The perigee moons are about 14% bigger and 30% brighter than the apogee moons.
The best time to view the perigee moons are when they are near the horizon. The moon shining through objects such as trees make the illusion that the moon is even bigger. The moon rises around 7:30pm on March 19.
The perigee moon does have an impact on tides but it is very minimal. The perigee moon can pull the tide about an inch higher than normal. Tonight's moon is 50,000 km closer to the earth but still a far 356,577 km away.
The forecast is great for viewing with clear skies tonight. This will be perfect conditions for taking some pictures and looking through a telescope.
Another phenomenon that will occur on Sunday March 20th is the Vernal Equinox, the start of astronomical spring. This is when the sun crosses over the equator. Spring officially arrives at 7:31pm.
Meteorological spring is already underway as it consists of the months of March, April, and May.
