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- 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 that the force of gravity is proportional to the product of the two masses (m 1 and m 2 ), and inversely proportional to the square of the distance
- Matter in Motion: Earths Changing Gravity | NASA Earthdata
This map, created using data from the Gravity Recovery and Climate Experiment (GRACE) mission, reveals variations in the Earth's gravity field Dark blue areas show areas with lower than normal gravity, such as the Indian Ocean (far right of image) and the Congo river basin in Africa Dark red areas indicate areas with higher than normal gravity
- 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 direct observation) matter, interacting gravitationally with the normal, visible matter in the universe, exists
- StarChild: Glossary - NASA
A cluster of stars, dust, and gas held together by gravity GAMMA-RAYS Penetrating short wave electromagnetic radiation of very high frequency GEOSYNCHRONOUS An orbit in which a satellite's rate of revolution matches the Earth's rate of rotation This allows the satellite to stay over the same site on the Earth's surface at all times
- StarChild: Stars - NASA
The last of the hydrogen gas in the outer shell is blown away to form a ring around the core This ring is called a planetary nebula When the last of the helium atoms in the core are fused into carbon atoms, the medium size star begins to die Gravity causes the last of the star's matter to collapse inward and compact
- 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 HURRICANE A very, very strong windstorm where the wind blows in circles at more than 46 kilometers per hour Heavy rains often come with the winds I J K
- Getting at Groundwater with Gravity | NASA Earthdata
This project, called the Gravity Recovery and Climate Experiment (GRACE), measures changes in the Earth’s gravity But how do gravitational differences tell scientists about the presence of groundwater? If the Earth were a perfectly round sphere, any point on the planet’s surface would have the same average gravity field
- Where did the Moon come from? - NASA
StarChild Question of the Month for October 2001 Question: Where did the Moon come from? Answer: Any theory which explains the existence of the Moon must naturally explain the following facts:
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