<p>Pretty much all models of the solar system that describe the planets as &quot;objects in space&quot; (rather than magical lights in the sky) feature coplanarity.</p>
<p>This is one of the first things one notices about the sky, that all the planets, are in a line along the zodiac, with a few degrees of variation to one side or another.  Ptolemy's model (which is likely the same as Hypatia's - there is no evidence that she developed a heliocentric model) features planets moving around the Earth in a plane, with slight movement up and down.  It is explicit in the Almagest.</p>
<p>Even Pythagoras' crystal spheres had planets (here strictly as lights attached to the spheres) moving in coplanar orbits. Only the fixed stars were off the plane.</p>

CC BY-SA 4.0
2022-12-22T08:02:26.980Z
2022-12-22T08:02:26.980Z
James K
<p>Aryabhata in 5th century along with other Indian astronomers, such as Varahamihira in the 6th century and Brahmagupta in the 7th century. Also Al-Battani in 9th century. These astronomers discussed the concept of coplanarity and the planes of the planetary orbits long before it was mathematically described by Newton and Kepler</p>

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2022-12-22T16:26:21.450Z
Could you please suggest any source from where I can ratify this information?
nuwe
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2022-12-23T17:45:06.273Z
@nuwe Hi so, Aryabhatta did propose that planets move in an elliptical orbits and also proposed the idea of "sighrocca" which is the basic planetary period in relation to the Sun (indirectly relating to heliocentric model). He also proposed the correct explanation for solar eclipse. These ideas can only be explained with the concept of coplanarity.
Pip Lark
CC BY-SA 4.0
2022-12-22T03:23:59.023Z
2022-12-22T03:23:59.023Z
Pip Lark
<p>When comparing Galileo, Copernicus and Hypathia models to describe the solar system, each of them agree on coplanarity, based on their representations. Anyways, it was not until Kepler and Newton that this could be mathematically stated. Even when not wrote formally using maths, what was the first time you know this property (of coplanarity) was mentioned (verbally and not inferred from representations) in the history of astronomy?</p>

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2022-12-22T10:30:51.633Z
"Hypathia model"?
Peter Erwin
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2022-12-22T10:31:48.577Z
Also, Galileo did not have his own model of the solar sytem; he used Copernicus's moel.
Peter Erwin
CC BY-SA 4.0
2024-02-07T13:00:17.630Z
@PeterErwin model not meant to be understood as a mathematical model but as a way to understood or explain something. I apologize for not stating that clearly!
nuwe
<solar-system><history>
First time mention of coplanarity between Solar Systems planets
nuwe
# First time mention of coplanarity between Solar Systems planets

(Asked by: username_0 on 2022-12-22)

When comparing Galileo, Copernicus and Hypathia models to describe the solar system, each of them agree on coplanarity, based on their representations. Anyways, it was not until Kepler and Newton that this could be mathematically stated. Even when not wrote formally using maths, what was the first time you know this property (of coplanarity) was mentioned (verbally and not inferred from representations) in the history of astronomy?

**Tags:** solar-system, history
> **Comments:**
> **username_1**: "Hypathia model"?  
> **username_1**: Also, Galileo did not have his own model of the solar sytem; he used Copernicus's moel.  
> **username_0**: @PeterErwin model not meant to be understood as a mathematical model but as a way to understood or explain something. I apologize for not stating that clearly!  

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## 2 answers

### Answer by username_2 on 2022-12-22. Score: 4

Pretty much all models of the solar system that describe the planets as "objects in space" (rather than magical lights in the sky) feature coplanarity.

This is one of the first things one notices about the sky, that all the planets, are in a line along the zodiac, with a few degrees of variation to one side or another. Ptolemy's model (which is likely the same as Hypatia's - there is no evidence that she developed a heliocentric model) features planets moving around the Earth in a plane, with slight movement up and down. It is explicit in the Almagest.

Even Pythagoras' crystal spheres had planets (here strictly as lights attached to the spheres) moving in coplanar orbits. Only the fixed stars were off the plane.


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### Answer by username_3 on 2022-12-22. Score: 3

Aryabhata in 5th century along with other Indian astronomers, such as Varahamihira in the 6th century and Brahmagupta in the 7th century. Also Al-Battani in 9th century. These astronomers discussed the concept of coplanarity and the planes of the planetary orbits long before it was mathematically described by Newton and Kepler

> **Comments:**
> **username_0**: Could you please suggest any source from where I can ratify this information?  
> **username_3**: @nuwe Hi so, Aryabhatta did propose that planets move in an elliptical orbits and also proposed the idea of "sighrocca" which is the basic planetary period in relation to the Sun (indirectly relating to heliocentric model). He also proposed the correct explanation for solar eclipse. These ideas can only be explained with the concept of coplanarity.  

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