![](https://static.wixstatic.com/media/c63751_7a7ae49700ee4953b98a07ef7888b473~mv2_d_1225_1837_s_2.jpeg/v1/fill/w_1225,h_1837,al_c,q_90,enc_avif,quality_auto/c63751_7a7ae49700ee4953b98a07ef7888b473~mv2_d_1225_1837_s_2.jpeg)
According to the canonical model, the proto-Earth was hit by a Mars-sized object approximately 4.5 billion years ago. The movie below shows entropy of the mantle (the extent of shock heating) in the red-yellow colors and iron core in grey. We developed a smoothed particle hydrodynamics (SPH) code from the ground up where a fluid is expressed as a collection of spherical particles.
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Feel free to download the movie from here: [canonical - entropy]
Please cite Nakajima and Stevenson (2014, 2015).
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Canonical Moon-forming impact (visualized by Roshan Mehta)
Canonical Moon-forming impact (visualized by Roshan Mehta)
![Canonical Moon-forming impact (visualized by Roshan Mehta)](https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_760,h_428,enc_auto/file.jpeg 1x, https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_1520,h_855,enc_auto/file.jpeg 2x, https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_2280,h_1283,enc_auto/file.jpeg 3x)
![Canonical impact (HR) (Roshan Mehta)](https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_375,h_211,enc_auto/file.jpeg 1x, https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_750,h_422,enc_auto/file.jpeg 2x, https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_1125,h_633,enc_auto/file.jpeg 3x)
Canonical impact (HR) (Roshan Mehta)
![Canonical impact model](https://static.wixstatic.com/media/c63751_af61bb7305cb4ae3aeea60f5069010d7f002.jpg/v1/fill/w_375,h_211,enc_auto/file.jpeg 1x, https://static.wixstatic.com/media/c63751_af61bb7305cb4ae3aeea60f5069010d7f002.jpg/v1/fill/w_750,h_422,enc_auto/file.jpeg 2x, https://static.wixstatic.com/media/c63751_af61bb7305cb4ae3aeea60f5069010d7f002.jpg/v1/fill/w_1125,h_633,enc_auto/file.jpeg 3x)
Canonical impact model
A number of impact models have been suggested, including (1) canonical model, where the proto-Earth is hit by a Mars-sized impactor, (2) fast-spinning Earth model, where the rapidly rotating proto-Earth is hit by a small impactor, (3) half-Earths model, where two half-Earth objects collide, and (4) multiple impact model, where the Moon formed out of multiple small impacts.
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We perform numerical simulations to represent (1)-(3) models as below. The green and yellow represent the mantle of the proto-Earth and impactor, whereas grey and white represent their iron cores, respectively.
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Feel free to download the movie from here:
[canonical - material] [fast-spinning Earth - material] [half-Earths - material]
Moon-forming impact models
Moon-forming impact models
![Moon-forming impact models](https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_760,h_428,enc_auto/file.jpeg 1x, https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_1520,h_855,enc_auto/file.jpeg 2x, https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_2280,h_1283,enc_auto/file.jpeg 3x)
![Canonical impact (HR) (Roshan Mehta)](https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_247,h_139,enc_auto/file.jpeg 1x, https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_493,h_278,enc_auto/file.jpeg 2x, https://static.wixstatic.com/media/c63751_cc3607dc44af421bab2b9482e369e425f002.jpg/v1/fill/w_740,h_416,enc_auto/file.jpeg 3x)
Canonical impact (HR) (Roshan Mehta)
![Canonical impact model](https://static.wixstatic.com/media/c63751_8ce3dcfe4cd446d59bd2c84cad6e85ebf002.jpg/v1/fill/w_247,h_139,enc_auto/file.jpeg 1x, https://static.wixstatic.com/media/c63751_8ce3dcfe4cd446d59bd2c84cad6e85ebf002.jpg/v1/fill/w_493,h_278,enc_auto/file.jpeg 2x, https://static.wixstatic.com/media/c63751_8ce3dcfe4cd446d59bd2c84cad6e85ebf002.jpg/v1/fill/w_740,h_416,enc_auto/file.jpeg 3x)
Canonical impact model
![Fast-spinning Earth](https://static.wixstatic.com/media/c63751_4e898646fd55426fa78192c6987699d3f002.jpg/v1/fill/w_247,h_139,enc_auto/file.jpeg 1x, https://static.wixstatic.com/media/c63751_4e898646fd55426fa78192c6987699d3f002.jpg/v1/fill/w_493,h_278,enc_auto/file.jpeg 2x, https://static.wixstatic.com/media/c63751_4e898646fd55426fa78192c6987699d3f002.jpg/v1/fill/w_740,h_416,enc_auto/file.jpeg 3x)