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The term Extrasolar moon refers to a smaller, natural (non-man-made) satellite that orbits an extrasolar planet or other extrasolar body larger than itself.

Satellites around brown dwarf

While a traditional definitions imply that the parent object orbited by the moon is a planet, the discovery of planet-sized satellites around brown dwarfs blurs the distinction between planets and moons, due to the low mass of such failed stars. To resolve this confusion, the International Astronomical Union declared, "Objects with true masses below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity) that orbit stars or stellar remnants are "planets" (no matter how they formed)."

Theory and search

There are no known extrasolar moons, but we theorize the existence around many exoplanets. However, future space telescopes such as Darwin and New Worlds Imager should search for moons orbiting extrasolar planets. To look for moons orbiting extrasolar planets, it must directly image extrasolar planets and use spectrograph to look for wobbling in parent planets just like wobbling in parent stars caused by planets, look for moons that pass in front of the parent planets or transit, or can even directly image moons.

Characteristics

There are many characteristics of extrasolar moons that are similar to moons in our solar system. Some extrasolar moons are rocky, icy, watery, or gas. Some moons could be as small as asteroids to as large as Neptune. Some moons may have atmosphere like Titan, some are volcanic like Io, and some have subsurface ocean like Europa.

They also have many characteristics that none of the moons have in our solar system. Some moons can be Earth-like that can support complex life and oceans and bodies of water like on Earth if giant planets orbit in the habitable zone. The moons can be lava worlds like Gliese 876 d. The moons can be Mars-like with a barren landscape under a thin atmosphere.

Designation

The designations of extrasolar moons has not yet been made by International Astronomical Union, but it will be when they start looking or discovering moons around many extrasolar planets.

The designation of extrasolar moons would probably use numbers after the planet designation. The number in designation increases according to order of discoveries or the distance from the parent exoplanets, depending what IAU improves.

Inferred examples

HD 28185 b has an Earth-like moon that can support Earth-type life.
HD 70642 b has an Europa-like moon that can have life in subsurface ocean.
Upsilon Andromedae c has a Mars-like moons covered with rocky and sandy deserts.
16 Cygni Bb has an Earth-like moon that undergo extreme seasonal changes due to high eccentricity of parent planet around parent star.
Tau Boötis Ab has a moon that covered partially with lava.
79 Ceti b has a barren moon.
70 Virginis b has two inferred moons. A first moon is yellow with a thick atmosphere of carbon dioxide and sulfurous haze that is two-and-a half times as massive as Earth. A smaller second moon is a lava world caused by huge tidal stress of the parent planet.
Pi Mensae b can have Neptune-mass moons since the planet is very massive.
HD 154345 b can have Mars-mass moons. It can have Europa-like moons with subsurface ocean under the icy crust and Titan-like moons with lakes or oceans of liquid methane that can have life on these moons.
Gliese 777 Ab has a rocky moon with a relatively smooth surface.
Gamma Cephei Ab has a dense, rocky moon with a mass of Mercury that bears the tectonic fractures and basaltic lava plains caused by the gravitational tides of parent jovian.
14 Herculis b has an oceanic moon that covered partially in liquid water and water ice. The partial liquid water ocean was caused by the melting of ice caused by strong gravitational tides of parent jovian.

External links

Shadow Moons: The Unknown Sub-Worlds that Might Harbor Life
Likely First Photo of Planet Beyond the Solar System
Working Group on Extrasolar Planets - Defintion of a "Planet" Position statement on the definition of a planet. (IAU)

@@ Line 1: / Line 1: @@
-The term '''Extrasolar moon''' refers to a natural (non-man-made) [[satellite]] that orbits an [[extrasolar planet]] or other extrasolar body larger than itself.
+The term '''Extrasolar moon''' refers to a smaller, natural (non-man-made) [[satellite]] that orbits an [[extrasolar planet]] or other extrasolar body larger than itself.
+==Satellites around brown dwarf==
-While a traditional definitions imply that the parent object orbited by the [[moon]] is a [[planet]], the discovery of planet-sized satellites around [[brown dwarf]]s blurs the distinction between planets and moons, due to the low mass of such failed [[star]]s. To resolve this confusion, the [[International Astronomical Union]] declared, "Objects with true masses below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity) that orbit stars or stellar remnants are "planets" (no matter how they formed)."
+While a traditional definitions imply that the parent object orbited by the [[moon]] is a [[planet]], the discovery of planet-sized satellites around [[brown dwarf]]s blurs the distinction between planets and moons, due to the low [[mass]] of such failed [[star]]s. To resolve this confusion, the [[International Astronomical Union]] declared, "Objects with true masses below the limiting mass for [[thermonuclear fusion]] of [[deuterium]] (currently calculated to be 13 [[Jupiter]] masses for objects of solar [[metallicity]]) that orbit stars or stellar remnants are "planets" (no matter how they formed)."
-There are no known extrasolar moons, but we theorize the existence around many exoplanets. However, future [[space telescope]]s such as [[Kepler Mission|Kepler]] and [[New Worlds Imager]] should search for moons orbiting extrasolar planets.
+==Theory and search==
+There are no known extrasolar moons, but we theorize the existence around many [[exoplanet]]s. However, future [[space telescope]]s such as [[Darwin (ESA)|Darwin]] and [[New Worlds Imager]] should search for moons orbiting extrasolar planets. To look for moons orbiting extrasolar planets, it must directly image extrasolar planets and use [[spectrograph]] to look for wobbling in parent planets just like wobbling in parent stars caused by planets, look for moons that pass in front of the parent planets or transit, or can even directly image moons.
+==Characteristics==
+There are many characteristics of extrasolar moons that are similar to [[moons in our solar system]]. Some extrasolar moons are rocky, icy, watery, or gas. Some moons could be as small as [[asteroid]]s to as large as [[Neptune]]. Some moons may have [[atmosphere]] like [[Titan (moon)|Titan]], some are [[volcanic]] like [[Io (moon)|Io]], and some have [[subsurface ocean]] like [[Europa (moon)|Europa]].
+They also have many characteristics that none of the moons have in our [[solar system]]. Some moons can be Earth-like that can support complex [[life]] and [[ocean]]s and bodies of water like on [[Earth]] if [[giant planet]]s orbit in the [[habitable zone]]. The moons can be [[lava]] worlds like [[Gliese 876 d]]. The moons can be [[Mars]]-like with a barren [[landscape]] under a thin atmosphere.
+==Designation==
+The designations of extrasolar moons has not yet been made by [[International Astronomical Union]], but it will be when they start looking or discovering moons around many extrasolar planets.
+The designation of extrasolar moons would probably use numbers after the planet designation. The number in designation increases according to order of discoveries or the distance from the parent exoplanets, depending what IAU improves.
+==Inferred examples==
+* [[HD 28185 b]] has an Earth-like moon that can support Earth-type life.
+* [[HD 70642 b]] has an Europa-like moon that can have life in subsurface ocean.
+* [[Upsilon Andromedae c]] has a Mars-like moons covered with rocky and sandy [[desert]]s.
+* [[16 Cygni Bb]] has an Earth-like moon that undergo extreme seasonal changes due to high [[eccentricity]] of parent planet around parent star.
+* [[Tau Boötis Ab]] has a moon that covered partially with lava.
+* [[79 Ceti b]] has a barren moon.
+* [[70 Virginis b]] has two inferred moons. A first moon is yellow with a thick atmosphere of [[carbon dioxide]] and sulfurous haze that is two-and-a half times as massive as Earth. A smaller second moon is a lava world caused by huge [[tidal force|tidal stress]] of the parent planet.
+* [[Pi Mensae b]] can have Neptune-mass moons since the planet is very massive.
+* [[HD 154345 b]] can have Mars-mass moons. It can have Europa-like moons with subsurface ocean under the icy crust and Titan-like moons with lakes or oceans of liquid [[methane]] that can have life on these moons.
+* [[Gliese 777 Ab]] has a rocky moon with a relatively smooth surface.
+* [[Gamma Cephei Ab]] has a dense, rocky moon with a mass of [[Mercury (planet)|Mercury]] that bears the tectonic fractures and basaltic lava plains caused by the gravitational tides of parent jovian.
+* [[14 Herculis b]] has an oceanic moon that covered partially in liquid water and water ice. The partial liquid water ocean was caused by the [[melting]] of ice caused by strong gravitational tides of parent jovian.
 ==See also==
@@ Line 13: / Line 44: @@
 * [http://www.space.com/scienceastronomy/planet_photo_040910.html Likely First Photo of Planet Beyond the Solar System]
 * [http://www.dtm.ciw.edu/boss/definition.html Working Group on Extrasolar Planets - Defintion of a "Planet"] Position statement on the definition of a planet. (IAU)
 [[Category:Moons]]
 [[Category:Extrasolar planets]]