Difference between revisions of "Earth"
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(Partially rewritten the introduction. Expanded physical characteristics section.) |
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'''Earth''' (aka '''Terra''') is the | '''Earth''' (aka '''Terra''') is the third [[planet]] orbiting the [[Sun]], an average yellow-dwarf [[star]] near the outer rim of the [[Milky Way]] [[galaxy]], and is the only known planet that supports life. It has a single, very large natural satellite referred to as "the Moon". | ||
Earth | Earth figures prominently as the homeworld of the [[human]] species in a great number of science-fiction stories, shows, movies, and books. | ||
Earth | == Earth in ''Star Trek'' == | ||
In [[Star Trek]], Earth is the capital of the [[United Federation of Planets]] and the center of most of the Federation's research and manufacturing facilities, especially those related to [[Starfleet]]. | |||
== Physical Characteristics == | |||
In [[versus]] debates, the physical characteristics of fictional inhabited planets are usually assumed to be close to those of Earth<ref>The average parameters of the core, mantle, and crust, as well as the gravitational binding energy, are based on the isotropic PREM model of Dziewonski and Anderson.</ref>, unless otherwise indicated in the story. | |||
== | {| style="width: 100%;" | ||
*Radius = | |- | ||
* | ! style="width: 50%;" | | ||
* | ! style="width: 50%;" | | ||
*Mass = 5. | |- | ||
*Core | | style="vertical-align: top;" | | ||
* | *Radius (volumetric mean) = 6371.0 km | ||
* | ** Equatorial = 6378.1 km | ||
* | ** Polar = 6356.8 km | ||
** Crust depth = 25 km (varies) | |||
** Mantle thickness = 2860 km | |||
** Core = 3480 km | |||
*Mass = 5.9736E24 kg | |||
** Atmosphere = 5.1E18 kg | |||
** Hydrosphere = 1.4E21 kg | |||
** Crust = 3.4E22 kg | |||
** Mantle = 4.0E24 kg | |||
** Core = 1.9E24 kg | |||
| style="vertical-align: top;" | | |||
*Distance from the Sun = 1.4960E11 m | |||
*Distance from the Moon = 3.8440E8 m | |||
*Escape velocity = 11.186 km/s | |||
*Bond albedo = 0.306 | |||
*Surface temperature = 288 K | |||
*Gravitational binding energy = 2.5E32 J | |||
*Density = 5514.8 kg/m³ | |||
** Atmosphere (surface) = 1.217 kg/m³ | |||
** Crust = 2700 kg/m³ | |||
** Mantle = 4500 kg/m³ | |||
** Core = 1.1E4 kg/m³ | |||
|} | |||
== Earth | == Notes and References== | ||
<references/> | |||
* Dziewonski, A.M. and D.L. Anderson. Preliminary Reference Earth Model (PREM), ''Phys. Earth Planet. Inter.'' '''25''', 297-356, 1981. | |||
* Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html Earth Face Sheet]" | |||
[[Category: Science Reference]] | |||
[[Category: Star Trek]] | [[Category: Star Trek]] | ||
Revision as of 11:29, 29 November 2007
Earth (aka Terra) is the third planet orbiting the Sun, an average yellow-dwarf star near the outer rim of the Milky Way galaxy, and is the only known planet that supports life. It has a single, very large natural satellite referred to as "the Moon".
Earth figures prominently as the homeworld of the human species in a great number of science-fiction stories, shows, movies, and books.
Earth in Star Trek
In Star Trek, Earth is the capital of the United Federation of Planets and the center of most of the Federation's research and manufacturing facilities, especially those related to Starfleet.
Physical Characteristics
In versus debates, the physical characteristics of fictional inhabited planets are usually assumed to be close to those of Earth[1], unless otherwise indicated in the story.
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Notes and References
- ↑ The average parameters of the core, mantle, and crust, as well as the gravitational binding energy, are based on the isotropic PREM model of Dziewonski and Anderson.
- Dziewonski, A.M. and D.L. Anderson. Preliminary Reference Earth Model (PREM), Phys. Earth Planet. Inter. 25, 297-356, 1981.
- Williams, David R. "Earth Face Sheet"