# How Many Natural Satellites Does The Earth Have **URL:** \ **Category:** Factual Questions\ **Created:** [June 13, 2015, 12:51am UTC](https://boards.straightdope.com/t/how-many-natural-satellites-does-the-earth-have/722398 "2015-06-13T00:51:44Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [June 13, 2015, 12:51am UTC](https://boards.straightdope.com/t/how-many-natural-satellites-does-the-earth-have/722398/1 "2015-06-13T00:51:44Z")
In elementary school I was taught that the Earth has exactly one natural satellite: The Moon. Then I heard, within the last year, that there was some small (as in, within a few dozen meters in diameter) chunk of rock that orbits the Earth, that can only be detected with specialized scientific equipment. So that makes two, that I’m aware of. How many are there? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 13, 2015, 1:03am UTC](https://boards.straightdope.com/t/how-many-natural-satellites-does-the-earth-have/722398/2 "2015-06-13T01:03:34Z")
AFAIK one known, the one you are referring to may be what I remember being described as a quasi satellite which more co-orbits the sun then orbits the earth, but hyped as a second moon. There are several of those From Wiki: > **[Quasi-satellite](https://en.wikipedia.org/wiki/Quasi-satellite)** > > A quasi-satellite is an object in a specific type of co-orbital configuration (1:1 orbital resonance) with a planet (or dwarf planet) where the object stays close to that planet over many orbital periods. > A quasi-satellite's orbit around the Sun takes the same time as the planet's, but has a different eccentricity (usually greater), as shown in the diagram. When viewed from the perspective of the planet by an observer facing the Sun, the quasi-satellite will appear to travel in an oblong retrogr... > [@](#): > > Earth > > As of 2014, Earth has several known quasi-satellites: (164207) 2004 GU9,[2] (277810) 2006 FV35,[3] and 2014 OL339.[4] > > 3753 Cruithne,[5] 2002 AA29,[1] and 2003 YN107 are minor planets in a horseshoe orbit that can transition into a quasi-satellite orbit. 2003 YN107 was in a quasi-satellite orbit from 1996 to 2006. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [June 13, 2015, 1:11am UTC](https://boards.straightdope.com/t/how-many-natural-satellites-does-the-earth-have/722398/3 "2015-06-13T01:11:07Z")
> [@](#): > > On 14 September 2006, an object estimated at 5 meters in diameter was discovered in near-polar orbit around Earth. Originally thought to be a third stage Saturn S-IVB booster from Apollo 12, it was later determined to be an asteroid and designated as 2006 RH120. The asteroid re-entered Solar orbit after 13 months and is expected to return to Earth orbit in 21 years. > > Computer models by astrophysicists Mikael Granvik, Jeremie Vaubaillon, and Robert Jedicke suggest that these “temporary satellites” should be quite common; and that “At any given time, there should be at least one natural Earth satellite of 1-meter diameter orbiting the Earth.” > > Such objects would remain in orbit for ten months on average, before returning to solar orbit once more, and so would make relatively easy targets for manned space exploration. > **[Claimed moons of Earth](https://en.wikipedia.org/wiki/Claimed_moons_of_Earth#Temporary_satellites)** > > Claims of the existence of other moons of Earth—that is, of one or more natural satellites with relatively stable orbits of Earth, other than the Moon—have existed for some time. Several candidates have been proposed, but none have been confirmed. Since the 19th century, scientists have made genuine searches for more moons, but the possibility has also been the subject of a number of dubious non-scientific speculations as well as a number of likely hoaxes. > Although the Moon is Earth's only natur... ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [June 13, 2015, 9:20am UTC](https://boards.straightdope.com/t/how-many-natural-satellites-does-the-earth-have/722398/4 "2015-06-13T09:20:13Z")
You should watch QI: > [@](#): > > In the A series, we said the earth had two moons. In the B series, we said there were either five or one, but definitely not two. These ideas were novel at the time (and quite controversial) but scientists now think the Earth has thousands of moons. At least one is the size of a washing machine, with a thousand more as big as a basketball. NASA calls them ‘mini-moons’ or Temporarily Captured Objects (TCOs). [http://qi.com/infocloud/the-moon](http://qi.com/infocloud/the-moon) ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [June 13, 2015, 2:52pm UTC](https://boards.straightdope.com/t/how-many-natural-satellites-does-the-earth-have/722398/5 "2015-06-13T14:52:01Z")
Here’s a reference from another thread: [http://www.universetoday.com/109666/can-moons-have-moons/](http://www.universetoday.com/109666/can-moons-have-moons/) sez it all