What is gravity? - NASA
Newton's "law" of gravity is a mathematical description of the way bodies are observed to attract one another, based on many scientific experiments and observations. The gravitational equation says …
Gravity/Gravitational Field - NASA Earthdata
Sep 30, 2025 · Gravity is the field around physical bodies, such as planets, that draws objects toward its center. Earth's gravitational field can be measured by orbiting satellites that can detect changes to it. …
StarChild: Glossary - NASA
GRAVITATIONAL PULL See Gravity GRAVITY The force of attraction between two objects which is influenced by the mass of the two objects and the distance between the two objects. GYROSCOPE …
Glacier Power: How do Glaciers Move? - NASA Earthdata
Sep 30, 2025 · Glaciers Are Solid Rivers A glacier is a large accumulation of many years of snow, transformed into ice. This solid crystalline material deforms (changes) and moves. Glaciers, also …
Teachers' Center Activity: Gravity Effects on Planet Motion - NASA
1. Introduction: Review the definition of gravity Drop a ball and explain why it falls downward Explain that the strength of a gravitational pull is determined by the masses of the objects involved and the …
How do we know that dark matter exists? - NASA
The cluster does not behave as scientists would expect it to if only the visible matter is generating the gravity present in the cluster. 'Dark matter' theory suggests that a huge amount of dark (invisible to …
StarChild: Galaxies - NASA
A galaxy is a cluster of stars, dust, and gas which is held together by gravity. Galaxies are scattered throughout the universe and they vary greatly in size. A galaxy may be alone or it may be in a large …
Getting at Groundwater with Gravity - NASA Earthdata
Dec 28, 2020 · Publication from NASA ESDIS describing research uses of data from EOSDIS - scientists use a pair of new satellites to keep up with groundwater resources.
StarChild: Glossary - NASA
GRAVITY The invisible force between objects that makes objects attract each other. GRAVITATIONAL PULL The attraction that one object has for another object due to the invisible force of gravity. H …
Crustal Dynamics Data Information System | NASA Earthdata
NASA's Crustal Dynamics Data Information System (CDDIS) provides data and information to support the international space geodesy community.