Image courtesy NASA.
On March 19th, 2011, earthlings will be treated to a close-up view of the Supermoon. It will be the closest the Moon has been to the Earth in 18 years. This Saturday, the Moon-Earth distance will be about 221,567 miles (356,577kms), compared to an average distance of 238,000 miles (382,900kms).
In an explanation given by Dr. James Garvin, chief scientist at NASA's Goddard Space Flight Center, the 'Supermoon' occurs when the moon is at its lowest perigee (closest point to Earth) and is most noticeable when there is a full Moon, as will be the case this year. Perigee Moons are as much as 14% wider and 30% brighter than lesser full Moons.
According to Dr.Garvin, while the Moon does have tidal effects on Earth’s water, and a relatively small effects upon its surface crust (compared to internal plate convection forces), the latest closest approach will not have any significant effects upon Earth in terms of earthquakes or other natural disasters.
A MoonDaily article estimates the lunar gravity effect at perigee “…increases tidewaters by a few centimeters (an inch or so), while local geography can amplify the effect to about 15 centimeters (6 inches)”.
So enjoy the visual spectacle, and don’t worry about any impending natural disaster. The Supermoon is best viewed when the moon is near the horizon, and it will look almost big enough to reach out and touch.
Trevor Williams is a University of Victoria Mechanical Engineering PhD candidate specializing in renewable energy, power grid modeling and plug-in hybrid electric vehicles. He has a bachelors in Aeronautical Engineering, a Masters in Management Science and over 23 years international experience in the space industry, having worked on Earth observation and telecommunications satellites. He is the author of the Eco-Geek blog.