Event Calendar

In September 1970, at a conference in Seattle, Washington, U.S. Senator Gaylord Nelson of Wisconsin announced that in the spring of 1970 there would be a nationwide grassroots demonstration on the environment. Senator Nelson first proposed the nationwide environmental protest to thrust the environment onto the national agenda. "It was a gamble," he recalls, "but it worked." Each year, the April 22 Earth Day marks the anniversary of the birth of the modern environmental movement in 1970. Earth Day is the only event celebrated simultaneously around the globe by people of all backgrounds, faiths, and nationalities. More than a half billion people participate in Earth Day Network campaigns every year. These campaigns promote healthy, sustainable environments, using clean energy, and encouraging recycling efforts.

A full moon is a lunar phase that occurs when the geocentric apparent longitudes of the Sun and Moon differ by 180 degrees; the Moon is then in opposition with the Sun. At this time, as seen by viewers on Earth, the hemisphere of the Moon that is facing the earth (the near side) is fully illuminated by the Sun and appears round. Only during a full moon is the opposite hemisphere of the Moon, which is not visible from Earth (the far side), completely unilluminated. As a lunar month is about 29.531, the period between full moons can be either 29 or 30 days.