Radio Astronomy is the study of natural radio energy emitted by galaxies, erupting stars, clouds of gas, pulsars and quasars. The Arecibo Radio Telescope enables astronomers to detect the faint radio emissions from these far off regions of the universe. Information extracted from these emissions allows them to measure the distances and masses of galaxies and how such galaxies form clusters. Radio pulses received from rotating neutron stars ( pulsars ) in our own galaxy are providing information about the physics of these fascinating objects. The fastest pulsar known was discovered at Arecibo.

Atmospheric Science

Atmospheric Science is the investigation of the earth's gaseous envelope. Experiments performed at Arecibo measure upper atmosphere composition, temperature and densities in order to understand the controlling physical processes. The Arecibo Radio Telescope can measure the growth and decay of disturbances in the changing layers of charged particles which populate the region known as the ionosphere ( altitudes above 30 miles ). The "big dish" is also used to study plasma physics processes in the electrically charged regions of the earth's atmosphere. where radio waves are influenced most.

Radar Astronomy

Radar Astronomy studies the celestial bodies in our solar system: planets, moons, asteroids and comets. Directed by the 1000 foot reflector, a powerful beam of radio energy is transmitted in the direction of the target object. A very small portion of this energy is reflected by the target, back in the direction of earth. This weak radio echo is collected, focused and detected by the Arecibo Telescope. The signal is processed, then analyzed to yield information about the surface roughness, composition, size, shape, rotation and path of the target object. The Arecibo Radio Telescope has been used to measure the rotation rate of Mercury and to generate surface maps of large areas on Mercury, Venus and the Moon, locating mountain ranges, craters and rift valleys. The first detection of radar echo €а from a comet was made at Arecibo.