New Horizons set forth on a mission to Pluto in 2006. Ten years later, the spacecraft is still on its way. Here, enthusiastic scholars predict what they will be like—likes, dislikes, hobbies, etc.—when New Horizons arrives at its...

An equation for the law of universal gravitation is stated. The weight equation (W=m*g) is related to the law. An interactive JavaScript form allows the user to practice determining the force of gravity and the acceleration of gravity...

An outstanding page describing Kepler's three laws of planetary motion.

A wealth of facts await you on this complete site. Topics include size, mass and gravity, length of day, orbit, distance from the sun, and more. A coloring page, quiz, fill-in-the-blanks activity, and interactive puzzle will challenge...