Glossary

G

G or g A symbol used to denote gravity or its effects, in particular the acceleration due to gravity; used as a unit of stress measurement for bodies undergoing acceleration

galactic cosmic rays Cosmic rays with energy levels as high as tens of billions of electron volts and velocities approaching the speed of light

Galactic Halo An enigmatic distribution of older stars that appears key to understanding the formation of our galaxy

gamma rays The shortest of electromagnetic radiations, emitted by some radioactive substances

GATT General Agreement on Tariffs and Trade

GBS Global Broadcast Service

GEO Geosynchronous Earth orbit

Geosat Geodetic and Geophysical Satellite

geostationary Traveling about the Earth's equator at an altitude of at least 35,000 kilometers and at a speed matching that of the Earth's rotation, thereby maintaining a constant relation to points on the Earth

geosynchronous geostationary

GGS Global Geospace Science (program)

GII Global Information Infrastructure

GIS Geographic Information System

GLOBE Global Learning and Observations to Benefit the Environment (program)

glove In relation to laminar flow control, a suction device employing tiny, laser-drilled holes to draw off turbulent air and produce a smooth (laminar) flow of air over an aircraft's wing

GM General Motors (Corporation)

GMT Greenwich Mean Time

GOES Geostationary Operational Environmental Satellite

GPHS General Purpose Heat Source

GPS Global Positioning System

GPS-MET GPS-Meteorological (experiment)

ground effect The temporary gain in lift during flight at very low altitudes caused by the compression of the air between the wings of an airplane and the ground

GSFC Goddard Space Flight Center (NASA)