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Near-Earth asteroid
Near-Earth asteroids (NEAs) are asteroids whose orbits are close to Earth's orbit. Some NEAs' orbits intersect Earth's so they pose a collision danger. On the other hand, NEAs are most easily ... > more -
Carl Sagan
Dr Carl Edward Sagan (November 9, 1934 - December 20, 1996) was an American astronomer, astrobiologist and highly successful science popularizer. He pioneered exobiology and promoted the Search for ... > more -
Solar wind
A solar wind is a stream of charged particles (i.e., a plasma) which are ejected from the upper atmosphere of a star. When originating from stars other than the Earth's Sun, it is sometimes called a ... > more -
Comet Hale-Bopp
Comet Hale-Bopp was probably the most widely observed comet of the 20th century, and one of the brightest seen for many decades. It was visible to the naked eye for a record 18 months, twice as long ... > more -
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet beyond the Solar System. As of 11 November 2006, 209 extrasolar planets have been discovered. Known exoplanets are members of planetary systems that ... > more -
Mercury (planet)
Mercury is the innermost and smallest planet in the solar system, orbiting the Sun once every 88 days. It ranges in brightness from about −2.0 to 5.5 in apparent magnitude, but is not easily ... > more -
Hybrid rocket
A hybrid rocket propulsion system comprises propellants of two different states of matter, the most common configuration being a rocket engine composed of a solid propellant lining a combustion ... > more -
Magnetosphere
A magnetosphere is the region around an astronomical object in which phenomena are dominated or organized by its magnetic field. Earth is surrounded by a magnetosphere, as are the magnetized planets ... > more
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