[nep-toon, -tyoon] 
| any whelk of the genus Neptunea, esp. N. decemcostata, common along the eastern coast of North America and having a shell with seven to ten raised reddish-brown spiral ridges on a pale beige or yellow background. |
[nep-toon, -tyoon] | 1. | the ancient Roman god of the sea, identified with the Greek god Poseidon. |
| 2. | the sea or ocean: Neptune's mighty roar. |
| 3. | Astronomy. the planet eighth in order from the sun, having an equatorial diameter of 30,200 mi. (48,600 km), a mean distance from the sun of 2794.4 million mi. (4497.1 million km), a period of revolution of 164.81 years, and two moons. |
| 4. | a township in E New Jersey. 28,366. |
| Nep·tune (něp'tōōn', -tyōōn') n.
[Latin Neptūnus.] Nep·tu'ni·an (-tōō'nē-ən, -tyōō'-) adj. |
In astronomy, a major planet, the eighth planet from the sun. Neptune is named for the Roman god of the sea. Neptune is similar in size and composition to Uranus. It is usually visible only through a telescope and was discovered in the 1840s. For a period ending in 1999, Pluto's orbit took it inside the orbit of neptune. (See solar system; see under “Mythology and Folklore.”)
Note: Some astronomers have suggested that Pluto is not a planet in the usual sense but is an object more like an asteroid, and that Neptune, therefore, is actually the outermost planet.
Neptune (něp't n') Pronunciation Key
The eighth planet from the Sun and the fourth largest, with a diameter almost four times that of Earth. Neptune is a gas giant with a very active weather system, exhibiting extremely long and powerful storms with the fastest winds observed in the solar system. Neptune's axis is tilted 28.8° from the plane of its orbit, and its summer and winter seasons each last 40 years. For a period of 20 years out of every 248, Pluto's highly elliptical orbit crosses within that of Neptune, making Neptune the farthest planet from the Sun during that period. Neptune has four faint rings and 13 known moons and appears blue due to the absorption of red light by the methane within its atmosphere. See Table at solar system. |
Neptune
A hypertext system for computer assisted software engineering, developed at Tektronix.
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