The inner planets, Mercury, Venus, Earth, and Mars, their sizes to scale.

A terrestrial planet, telluric planet or rocky planet is a planet that is primarily composed of silicate rocks. The term is derived from the Latin word for Earth, "Terra", so an alternative definition would be that these are planets which are, in some notable fashion, "Earth-like". Terrestrial planets are substantially different from gas giants, which might not have solid surfaces and are composed mostly of some combination of hydrogen, helium, and water existing in various physical states. Image File history File linksMetadata Download high resolution version (1500x653, 488 KB)Terrestrial planet size comparisons. ... Image File history File linksMetadata Download high resolution version (1500x653, 488 KB)Terrestrial planet size comparisons. ... This article is about the planet. ... Adjectives: Venusian or (rarely) Cytherean Atmosphere Surface pressure: 9. ... This article is about Earth as a planet. ... Adjectives: Martian Atmosphere Surface pressure: 0. ... The eight planets and three dwarf planets of the Solar System. ... In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ... For other uses, see Rock (disambiguation). ... For other uses, see Latin (disambiguation). ... This article is about Earth as a planet. ... This article does not cite any references or sources. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Standard atomic weight 4. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ...

Structure

Terrestrial planets all have roughly the same structure: a central metallic core, mostly iron, with a surrounding silicate mantle. The Moon is similar, but lacks an iron core. Terrestrial planets have canyons, craters, mountains, and volcanoes. Terrestrial planets possess secondary atmospheres — atmospheres generated through internal vulcanism or comet impacts, as opposed to the gas giants, which possess primary atmospheres — atmospheres captured directly from the original solar nebula. For other uses, see Iron (disambiguation). ... Earth cutaway from core to exosphere. ... This article is about Earths moon. ... Grand Canyon, Arizona Noravank Monastery complex and canyon in Armenia. ... Tycho crater on Earths moon. ... For other uses, see Mountain (disambiguation). ... For other uses, see Volcano (disambiguation). ... A secondary atmosphere is an atmosphere of a planet that did not form by accretion during the formation of the planets sun. ... A primary atmosphere is an atmosphere of a planet that forms by accretion of gaseous matter from the accretion disc of the planets sun. ... This article or section does not cite any references or sources. ...

Theoretically, there are two types of terrestrial or rocky planets, one dominated by silicon compounds and another dominated by carbon compounds, like carbonaceous chondrite asteroids. These are the silicate planets and carbon planets (or "diamond planets") respectively. Some carbonaceous chondrites. ... Planets orbiting the pulsar PSR 1257+12 may be carbon planets A carbon planet, also referred to as a diamond planet or carbide planet is a theoretical type of terrestrial planet proposed by Marc Kuchner with internal layers of diamond many kilometres thick. ...

Solar terrestrial planets

Earth's solar system has four terrestrial planets: Mercury, Venus, Earth and Mars, and one terrestrial dwarf planet, Ceres. Objects like Pluto are similar to terrestrial planets in the fact that they do have a solid surface, but are composed of more icy materials (see Ice dwarf). During the formation of the solar system, there were probably many more (planetesimals), but they have all merged with or been destroyed by the four remaining worlds in the solar nebula. Only one terrestrial planet, Earth, is known to have an active hydrosphere. This article is about the Solar System. ... This article is about the planet. ... (*min temperature refers to cloud tops only) Atmospheric characteristics Atmospheric pressure 9. ... This article is about Earth as a planet. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... Artists impression of Pluto (background) and Charon (foreground). ... Spectral type: G[8] Absolute magnitude: 3. ... Atmospheric characteristics Atmospheric pressure 0. ... Please wikify (format) this article or section as suggested in the Guide to layout and the Manual of Style. ... In cosmogony, planetesimals are objects thought to exist within solar nebulae. ... This article or section does not cite any references or sources. ... The movement of water around, over, and through the Earth is called the water cycle, a key process of the hydrosphere. ...

Extrasolar terrestrial planets

See also: Super-earth and Pulsar planet

SIM PlanetQuest will be able to detect Earth-sized planets, such as in this artist's rendering.

The majority of planets found outside our solar system to date have been gas giants, simply because gas giants are larger and therefore easier to see or infer from observation. However, a number of extrasolar planets are known or suspected to be terrestrial. Gliese 581 c, a super-Earth and its star as rendered in Celestia. ... An artists conception of PSR 1257+12s system of planets Pulsars are rapidly rotating neutron stars. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Artists concept of Space Interferometry Mission spacecraft The Space Interferometry Mission (SIM), also called SIM PlanetQuest, is a NASA instrument originally expected to be launched in December of 2011; however due to budget cuts it will now launch no sooner than between October 2014 and April 2015. ... This article is about the Solar System. ... A gas giant is a large planet that is not composed mostly of rock or other solid matter. ...

Aleksander Wolszczan detected the first extrasolar terrestrial planets. The three planets orbit the pulsar PSR B1257+12 with masses of 0.02, 4.3, and 3.9 times that of Earth's. They were discovered by accident: their transit caused interruptions in the pulsar's radio emissions (had they not been orbiting around a pulsar, they would not have been found). Aleksander Wolszczan (b. ... A planet (from the Greek πλανήτης, planetes or wanderers) is a body of considerable mass that orbits a star and that produces very little or no energy through nuclear fusion. ... It has been suggested that Radio pulsar be merged into this article or section. ... PSR B1257+12 (sometimes abbreviated to PSR 1257+12) is a pulsar located 980 light years from Earth. ...

When 51 Pegasi b, the first extrasolar planet found around a fusing star, was discovered, many astronomers assumed it must be a gigantic terrestrial, as it was assumed no gas giant could exist as close to its star (0.052 AU) as 51 Pegasi b did. However, subsequent diameter measurements of a similar extrasolar planet (HD 209458 b), which transited its star showed that these objects were indeed gas giants. 51 Pegasi b (also written as 51 Peg b) is the first planet discovered around a sun-like star outside of the solar system. ... Cross section of a red giant showing nucleosynthesis and elements formed Stellar nucleosynthesis is the collective term for the nuclear reactions taking place in stars to build the nuclei of the heavier elements. ... HD 209458 b is an extrasolar planet that orbits the Sun-like star HD 209458 in the constellation Pegasus, some 150 light-years from Earths solar system, with evidence of water vapor. ...

In June 2005, the first planet around a fusing star that is almost certainly terrestrial was found orbiting around the red dwarf star Gliese 876, 15 light years away. That planet has a mass of 5 to 7 times that of earth and an orbital period of just two Earth days. 2005 : January - February - March - April - May - June - July - August - September - October - November - December- → Deaths in June June 27: Shelby Foote June 27: John T. Walton June 26: Richard Whiteley June 25: John Fiedler June 25: Chet Helms June 24: Paul Winchell June 21: Jaime Cardinal Sin June 20: Jack Kilby... For the type of star, see Red dwarf. ... STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... Gliese 876 is a red dwarf star located approximately 15 light-years away in the constellation Aquarius. ...

On 10 August 2005, Probing Lensing Anomalies NETwork/Robotic Telescope Network (PLANET/RoboNet) and Optical Gravitational Lensing Experiment (OGLE) observed the signature of a cold planet designated OGLE-2005-BLG-390Lb, about 5.5 times the mass of Earth, orbiting a star about 21,000 light years away in the constellation Scorpius. The newly discovered planet orbits its parent star at a distance similar to that of our solar system's asteroid belt. The planet revealed its existence through a technique known as gravitational microlensing, currently unique in its capability to detect cool planets with masses down to that of Earth. is the 222nd day of the year (223rd in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... The Probing Lensing Anomalies NETwork (PLANET) collaboration coordinates a network of telescopes to rapidly sample photometric measurements of the magnification of stars in the galactic bulge undergoing gravitational microlensing by intervening foreground stars (or other compact massive objects). ... The Optical Gravitational Lensing Experiment (OGLE) survey. ... OGLE-2005-BLG-390Lb is a super-Earth extrasolar planet orbiting the star OGLE-2005-BLG-390L, which is situated 21,500 ± 3,300 light years away from Earth, near the center of the Milky Way galaxy. ... A light-year or lightyear (symbol: ly) is a unit of measurement of length, specifically the distance light travels in vacuum in one year. ... For details on the physical properties of bodies in the asteroid belt see Asteroid and Main-belt comet. ... Gravitational microlensing is an astronomical technique used to detect planets - stellar mass objects in space using the gravitational lens effect. ...

Re-creation of carbon planet

In April 2007, a team of 11 European scientists announced the discovery of a planet outside our solar system that is potentially habitable, with Earth-like temperatures. The planet was discovered by the European Southern Observatory's telescope in La Silla, Chile, which has a special instrument that splits light to find wobbles in different wave lengths. Those wobbles can reveal the existence of other worlds. What they revealed is a planet circling the red dwarf star, Gliese 581. The discovery of the new planet, named Gliese 581 c, is sure to fuel studies of planets circling similar dim stars. About 80 percent of the stars near Earth are red dwarfs. The new planet is about five times heavier than Earth, classifying it as a super-earth. Its discoverers aren't certain if it is rocky, like Earth, or if it is a frozen ice ball with liquid water on the surface. If it is rocky like Earth, which is what the prevailing theory proposes, it has a diameter about 1 1/2 times bigger than our planet. If it is an iceball, it would be even bigger. Image File history File links Size of this preview: 651 × 600 pixelsFull resolution (761 × 701 pixel, file size: 53 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Terrestrial planet ... Image File history File links Size of this preview: 651 × 600 pixelsFull resolution (761 × 701 pixel, file size: 53 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Terrestrial planet ... Planets orbiting the pulsar PSR 1257+12 may be carbon planets A carbon planet, also referred to as a diamond planet or carbide planet is a theoretical type of terrestrial planet proposed by Marc Kuchner with internal layers of diamond many kilometres thick. ... April 2007 is the fourth month of the year. ... The European Southern Observatory (ESO) is an international astronomical organisation, composed and supported by ten countries from the European Union plus Switzerland. ... La Silla Observatory is an astronomical observatory in Chile with eighteen telescopes. ... Gliese 581 (IPA: ) is an M2. ... Gliese 581 c (IPA: ) is a super-earth extrasolar planet orbiting the red dwarf star Gliese 581. ... Gliese 581 c, a super-Earth and its star as rendered in Celestia. ...

A number of telescopes capable of directly imaging extrasolar terrestrial planets are on the drawing board. These include the Terrestrial Planet Finder, Space Interferometry Mission, Darwin, New Worlds Mission, the kepler mission, and Overwhelmingly Large Telescope. Terrestrial Planet Finder - Infrared interferometer concept The Terrestrial Planet Finder (TPF) is a plan by NASA for a telescope system that would be capable of detecting extrasolar terrestrial planets. ... Artists concept of Space Interferometry Mission spacecraft The Space Interferometry Mission (SIM), also called SIM PlanetQuest, is a NASA instrument originally expected to be launched in December of 2011; however due to budget cuts it will now launch no sooner than between October 2014 and April 2015. ... Darwin is a proposed European Space Agency (ESA) mission designed to directly detect Earth-like planets orbiting nearby stars, and search for evidence of life on these planets. ... This article does not cite any references or sources. ... The Kepler Mission is a space observatory being developed by NASA that will search for extrasolar planets and will only be the second space-based telescope particularly constructed for that task, the first one being COROT. For this purpose, it will observe the brightness of about 100,000 stars over... The Overwhelmingly Large Telescope (OWL) is a conceptual design by the European Southern Observatory organization for a telescope which was intended to have a single aperture of 100 meters in diameter, but was later scaled down to a 60 meter diameter telescope. ...

Most Earthlike exoplanets

PSR B1257+12 (sometimes abbreviated to PSR 1257+12) is a pulsar located 980 light years from Earth. ... PSR 1257+12 (also catalogued as PSR B1257+12, PSR 1300+1240, or PSR J1300+1240) is a pulsar located 980 light years from Earth. ... HD 142 is a 6th magnitude star in the constellation Phoenix. ... HD 142 is a 6th magnitude star in the constellation Phoenix. ... It has been suggested that this article or section be merged into HD 28185. ... HD 28185 is a G5V Star in the Constellation Eridanus. ... HD 128311 is a K0V star in the constellation Boötes. ... HD 128311 is a K0V star in the constellation Boötes. ... The kelvin (symbol: K) is a unit increment of temperature and is one of the seven SI base units. ... Mu Arae e was announced on August, 2006. ... Mu Arae (NASA Nstars database) Mu Arae (μ Ara / μ Arae) is a 5th magnitude yellow-orange G-type star similar to our Sun. ... Gliese 581 c (IPA: ) is a super-earth extrasolar planet orbiting the red dwarf star Gliese 581. ... Gliese 581 (IPA: ) is an M2. ... It has been suggested that Goldilocks phenomenon be merged into this article or section. ...

See also

A view of planet Earth (painting)

• Jovian planet/Gas giant planet
• Chthonian planet
• Dwarf planet
• Gliese 581 c
• Planetarium
• Planetary habitability

Image File history File linksMetadata Earth-Erde. ... Image File history File linksMetadata Earth-Erde. ... From top: Neptune, Uranus, Saturn, and Jupiter. ... This article does not cite any references or sources. ... A Chthonian planet (sometimes misspelled Cthonian), is a gas giant with its hydrogen and helium atmosphere stripped away due to its closeness to its star. ... Artists impression of Pluto (background) and Charon (foreground). ... Gliese 581 c (IPA: ) is a super-earth extrasolar planet orbiting the red dwarf star Gliese 581. ... For the song by Ai Otsuka, see Planetarium (song) // A planetarium is a theatre built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation. ... Understanding planetary habitability is partly an extrapolation of the Earths conditions, as it is the only planet currently known to support life. ...

References

• Astronomers Find First Earth-like Planet in Habitable Zone ESO - European Organisation for Astronomical Research in the Southern Hemisphere, 27 April 2007
• Found: one Earth-like planet Astronomers use gravity lensing to spot homely planets. By Mark Peplow, News @ Nature.com, 25 January 2006.
• Beaulieu J.P., et al. (2006) Nature, 439, 437-440.
• National Science Foundation press release "Closer to Home."
• A New Path to New Earths National Science Foundation webcast.
• Ogling Distant Stars National Science Foundation grant report.
• Wolszczan's Pulsar Planets.
• PLANET Homepage.
• RoboNet Homepage.
• OGLE Homepage.
• MOA Homepage.

External links

• SPACE.com: Q&A: The IAU's Proposed Planet Definition 16 August 2006 2:00 am ET
• BBC News: Q&A New planets proposal Wednesday, 16 August 2006, 13:36 GMT 14:36 UK

v • d • e The Solar System
The Sun · Mercury · Venus · Earth · Mars · Ceres · Jupiter · Saturn · Uranus · Neptune · Pluto · Eris
Planets · Dwarf planets · Moons: Terrestrial · Martian · Jovian · Saturnian · Uranian · Neptunian · Plutonian · Eridian
Small bodies:   Meteoroids · Asteroids/Asteroid moons (Asteroid belt) · Centaurs · TNOs (Kuiper belt/Scattered disc) · Comets (Oort cloud)
See also astronomical objects, the solar system's list of objects, sorted by radius or mass, and the Solar System Portal