| Prehistory | ||||
|---|---|---|---|---|
| Name | Image | Other designation | Notes | |
| Sun | Star | In Ptolemy's geocentric model, the Earth was believed to be at the center of the cosmos. Seven planets were placed in orbit around it in an order of increasing distance from the Earth, as established by the Greek Stoics: the Moon, Mercury, Venus, the Sun, Mars, Jupiter and Saturn. This list included two objects, the Sun and the Moon, which are no longer considered to be planets; it also excluded the Earth. | ||
| Moon | Earth I | In the Copernican system, the Moon was considered to be no longer a planet but a natural satellite of the Earth, and was the only body in that system whose revolution was not centered on the Sun. | ||
| Mercury | 1st Planet | The inner planets, Mercury and Venus, and the outer planets, Mars, Jupiter and Saturn, were identified by ancient Babylonian astronomers in the 2nd millennium BC.
By Aristarchus of Samos, and later in Nicolaus Copernicus' heliocentric system (De Revolutionibus Orbium Coelestium, 1543) the Earth came to be considered a planet revolving with the other planets around the Sun, in the following order of distance from the Sun: Mercury, Venus, Earth, Mars, Jupiter, and Saturn. The Sun, now situated near the center of revolution, was no longer considered a planet. |
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| Venus | 2nd Planet | |||
| Earth | 3rd Planet | |||
| Mars | 4th Planet | |||
| Jupiter | 5th Planet | |||
| Saturn | 6th Planet | |||
Read more about this topic: Timeline Of Discovery Of Solar System Planets And Their Moons