Eileen Jencks, age 12, Of Matteson, Ill., for her question:

What is the meaning to have Escape Velocity?

WE are held on the ground by the force of the Earth's gravity.  We escape this mighty pull for a moment when we use muscular Energy to dump.  When we toss a ball in the air, WE give it Energy to counteract the Earth's gravity.  If we could make the ball. Fly at seven and a half miles a second, it would escape the Earth's gravity altogether and never return.

Seven and a half miles a Second is the Velocity necessary to escape the Earth’ gravity.  On massive Jupiter, where the gravity is much stronger, the Escape velocity is 38 miles a second.  The Escape Velocity on our little moon is about one and a half miles a second.