Giant Impact Hypothesis.

[Boris_Badenov]

The Giant Impact Hypothesis says an object hit earth late in Earth's growth process, blowing out rocky debris. A fraction of that debris went into orbit around the Earth and aggregated into the moon. <br /> My question is, has the impactor been given a name? <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[vandivx]

http://csep10.phys.utk.edu/astr161/lect/moon/moon_formation.html<br /><br /><font color="yellow">Five serious theories have been proposed for the formation of the Moon (not counting the one involving green cheese):<br /><br /> 1. The Fission Theory: The Moon was once part of the Earth and somehow separated from the Earth early in the history of the Solar System. The present Pacific Ocean basin is the most popular site for the part of the Earth from which the Moon came.<br /><br /> 2. The Capture Theory: The Moon was formed somewhere else, and was later captured by the gravitational field of the Earth.<br /><br /> 3. The Condensation Theory: The Moon and the Earth condensed together from the original nebula that formed the Solar System.<br /><br /> 4. The Colliding Planetesimals Theory: The interaction of earth-orbiting and Sun-orbiting planetesimals (very large chunks of rocks like asteroids) early in the history of the Solar System led to their breakup. The Moon condensed from this debris.<br /><br /> 5. The Ejected Ring Theory: A planetesimal the size of Mars struck the earth, ejecting large volumes of matter. A disk of orbiting material was formed, and this matter eventually condensed to form the Moon in orbit around the Earth. <br /><br />Constraints from Recent Data<br />A detailed comparison of the properties of Lunar and Earth rock samples has placed very strong constraints on the possible validity of these hypotheses. For example, if the Moon came from material that once made up the Earth, then Lunar and Terrestrial rocks should be much more similar in composition than if the Moon was formed somewhere else and only later was captured by the Earth.<br /><br />These analyses indicate that the abundances of elements in Lunar and Terrestrial material are sufficiently different to make it unlikely that the Moon formed directly from the Earth. Generally, work over the last 10 years</font> <div class="Discussion_UserSignature"> </div>

 

[odysseus145]

I've heard the name Orpheus used on a Discovery channel special. <div class="Discussion_UserSignature"> </div>

 

[bonzelite]

<font color="yellow"><br />3. The Condensation Theory: The Moon and the Earth condensed together from the original nebula that formed the Solar System. </font><br /><br />^^^i believe this one

 

[dragon04]

Let's call it Buster. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[enigma10]

It was called operation moon the earth. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>

 

[Boris_Badenov]

Thanks for the hint, Orpheus led me to this;<br /><br /> Giant impact hypothesis <br /><br />The giant impact hypothesis (sometimes referred to as the big whack, or less frequently, the big splash) is the now-dominant scientific theory for the formation of the Moon, which is thought to have formed as a result of a collision between the young Earth and a Mars-sized body that is sometimes called<i><font color="orange"> Theia</font>/i> or occasionally Orpheus. The name of Theia /'theI.a/ is derived from Greek mythology, as Theia was the Titan who gave birth to the Moon goddess Selene. The hypothesis - not to be confused with that of the "Big Bang", or celestial based theories of Dinosaur extinction - was first proposed in a paper published in Icarus in 1975 by Drs. William K. Hartmann and Donald R. Davis.<br /><br /> That was the name I was looking for.</i> <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>