/ Source: Space.com
By Charles Q. Choi, Space.com
The Moon May Have A new study found out that a huge Mars-sized stone had hit a magma-covered newborn earth.
The Earth came together 4.5 billion years ago, and earlier research indicated that the Moon came up shortly thereafter. For the past three decades, the predominant explanation for the origin of the moon has been that the moon resulted from the collision of two protoplanets or embryonic worlds. One of them was the Newborn Earth, and the other was a Mars-sized rock called Theia, named after the Moon Mother in Greek myth. The moon then merged from the rubble.
This "Giant Impact Hypothesis" seemed to explain many details about the Earth and the Moon, such as the size of the Moon compared to the Earth and the rotational speeds of the two bodies. Over the last 1
Related: How the Moon Formed: 5 Wild Lunar Theories
Computer Models of the A scenario with a huge impact often states that more than 60 percent of the moon should consist of material from Theia. The problem is that most bodies in the solar system have a unique chemical composition, and Earth, Theia, and therefore the Moon. Rock samples from the Moon, however, show that its composition is eerily more similar to Earth than such models would predict in versions of elements called isotopes. (The isotopes of an element each have a different number of neutrons.)
To solve this puzzle, a recent moonformation model suggested that the moon could have formed from such a violent impact that it took up a large portion of the In the early earth, the moon, which emanates from the resulting donut-shaped mass, is called Synestia. Another suggested colliding with a fast-moving proto-earth. However, a disadvantage of such models is that these scenarios require unlikely impact conditions, said study author Natsuki Hosono, a planetary scientist at the Japanese Agency for Marine Earth Science and Technology in Yokohama, told Space.com.
Related Topics: Moon Creation: Moon Evolution (Infographic)
To solve this puzzle, Hosono's team now suggests that much of Earth's material orbits could have reached if the earth was partially formed melted at the time of the gigantic impact.
Researchers developed computer models that simulate Earth-covered magma, which, according to most models of the planetary formation, is thought to be the planet shortly after birth. Next, they investigated what happened when a Mars stone over a tenth of Earth's mass struck that molten protoplanet.
The scientists discovered that even a blow from Theia could strike more than 70 percent of the moon-forming debris from the Earth's interior magma-ocean, as molten rock was easier to blow from the earth than solid material. These results could help explain the compositional similarities between the Moon and Earth, and they also explained details such as their rotational speed.
"Previous work on the moon formation has basically ignored the effect of the magma ocean," Hosono told Space. com "Our research came to the conclusion that the magma ocean is one of the most important things for the moon-forming giant impact."
The new model suggests that the amount of debris from a molten earth was comparable to the current mass of the ocean moon. Earlier work suggested, however, that the gigantic impact to build the Moon initially required a lot of debris equivalent to about three to four times the mass of the Moon, Hosono said. Future research might consider larger masses for Theia and the rotation factor of the Proto-Earth to see if this could lead to a lot of debris to form a moon of the correct size, Hosono added.
The scientists brought their findings online today (April 29 in the journal Nature Geoscience.
Follow Charles Q. Choi on Twitter @cqchoi .) Follow us on Twitter  @Spacedotcom and Facebook .
SIGN UP FOR THE MACH NEWSLETTER AND FOLLOW NBC NEWS MAKE TWITTER FACEBOOK AND INSTAGRAM.