You are here

Glossary

G

galactic

Having to do with the galaxy. A galaxy is one of billions of large systems of stars and gas, held together by gravity, that make up the universe.


Click for citation

gamma rays

A high energy photon, especially as emitted by a nucleus in a transition between two energy levels.


Click for citation

GEC

Geospace Electrodynamic Connections

GEO

Geostationary orbit

Geoid

The surface within or around the earth that is everywhere perpendicular to the direction of gravity and coincides with mean sea level in the oceans at rest. Sea level of a moving ocean has topography, the topography that is measured by altimeter satellites to observe ocean currents.


Click for citation

geospace

The area of space surrounding the Earth but outside of the Earth's atmosphere - influenced by the particles and fields coming from the Sun.

GEOSS

Global Earth Observation System of Systems

geostationary

Describes an orbit in which a satellite is always in the same position (appears stationary) with respect to the rotating Earth.


Click for citation

GIS

geographic information systems

GLAST

Gamma-ray Large Area Space Telescope

GN

Ground Network

GPM

Global Precipitation Measurement

GPS

global positioning system

GSRP

Graduate Student Researchers Program

Gyre

A great, circular motion of water in each of the major ocean basins centered on subtropical high-pressure region, with circulation clockwise in the northern hemisphere and counterclockwise in the southern hemisphere.


Click for citation