Near Earth's surface
Objects accelerate downward because Earth exerts a gravitational force on them.
Mass and weight differ
Mass measures how much matter an object contains; weight is a force caused by gravity.
Orbits are continual falling
An orbiting object is falling under gravity while moving sideways fast enough to keep missing the surface.
Gravity shapes the universe
It organizes planets, stars, galaxies and large-scale structures.
Source trail: NASA: star basics
This page explains scientific concepts for general learning. It does not replace laboratory safety procedures, professional engineering guidance, or individualized medical advice.