A:
Ask Mr Sunspot - Questions are answered about the Sun, Moon, planets, stars, and other astronomical topics [National Science Foundation (NSF), National Optical Astronomy Observatory (NOAO), National Solar Observatory]

Astrobiology Magazine - Information and discussion groups devoted to Extrasolar life; Extreme life; Life and Giant Planets; Mars Life; Meteors, Comets, and Asteroids; Missions; New Planets; Stellar Evolution; Terrestrial Climate History; Terrestrial Origins. [National Aeronautics and Space Administration (NASA), Ames Research Center (ARC)]

Astrogeology Research Program - Primary homepage for the Astrogeology Research Program with links to solar system, space missions, technology, data & information, research programs for geology, remote sensing, and ice & polar, hot topics, photo gallery, and Astro Kids [Department of the Interior, U.S. Geological Survey (USGS), Astrogeology Research Program]

Atmospheric Laser Spectroscopy - Seeks to understand the photochemistry, dynamics, and evolution of Earth and planetary atmospheres [National Aeronautics and Space Administration (NASA), Jet Propulsion Laboratory (JPL)]

E:
Education Gateway - Materials related to earth science, robotics, spaceflight, the origins of life and the universe, and the Solar System [National Aeronautics and Space Administration (NASA), Jet Propulsion Laboratory (JPL)]

G:
Goddard Institute for Space Studies (GISS) - Prediction of atmospheric and climate changes in the 21st century based on research of global datasets [National Aeronautics and Space Administration (NASA), Goddard Space Flight Center (GSFC)]

Goddard Laboratory for Atmospheres - Advancing knowledge and understanding of the atmospheres of the Earth and other planets [National Aeronautics and Space Administration (NASA), Goddard Space Flight Center (GSFC)]

L:
Lunar and Planetary Institute - A focus for academic participation in studies of the current state, evolution, and formation of the solar system [National Aeronautics and Space Administration (NASA), Johnson Space Center (JSC)]

M:
Mission to Saturn & Titan - Cassini-Huygens [National Aeronautics and Space Administration (NASA), Jet Propulsion Laboratory (JPL)]

N:
NASA - Spooky Space 'Sounds' - Elusive sounds of howling planets and whistling helium [National Aeronautics and Space Administration (NASA)]

NTRS (NASA Technical Reports Server) - Search for reports, journal articles, and conference proceedings [National Aeronautics and Space Administration (NASA)]

P:
Planet Quest - Features the activities NASA is undertaking to look for planets [National Aeronautics and Space Administration (NASA), Jet Propulsion Laboratory (JPL)]

Planetary Image Archive (PIA) - An image database of Solar System planets and moons captured by NASA spacecraft including the Hubble telescope [National Aeronautics and Space Administration (NASA), Jet Propulsion Laboratory (JPL)]

Primer on Space Weather. - Information on solar flares, Coronal Mass Ejections (CMEs,) and magnetic storms and their effects on the earth. [Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA)]

S:
Spectroscopy Laboratory - Links to Spectroscopy Lab projects to identify and map materials through spectroscopic remote sensing (imaging spectroscopy, hyperspectral imaging, imaging spectrometry, ultraspectral imaging, etc.) on the earth and in space. [Department of the Interior, U.S. Geological Survey (USGS)]