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  2. Comparative planetary science - Wikipedia

    en.wikipedia.org/wiki/Comparative_planetary_science

    The term "comparative planetology" was coined by George Gamow, who reasoned that to fully understand our own planet, we must study others. Poldervaart focused on the Moon, stating "An adequate picture of this original planet and its development to the present earth is of great significance, is in fact the ultimate goal of geology as the science leading to knowledge and understanding of earth's ...

  3. Heliocentrism - Wikipedia

    en.wikipedia.org/wiki/Heliocentrism

    The movements of the Moon, the planets, and the Sun around the static Earth in the Ptolemaic geocentric model (upper panel) in comparison to the orbits of the planets and the daily-rotating Earth around the Sun in the Copernican heliocentric model (lower panel). In both models, the Moon rotates around the Earth.

  4. Ancient Greek astronomy - Wikipedia

    en.wikipedia.org/wiki/Ancient_Greek_astronomy

    Book 3 provides a theory of the sun. Book 4 provides an equivalent treatment for the moon. Book 5 deals with the new complications that arise from applying Ptolemy's theory to the moon, as opposed to the simpler case of the sun. Book 6 combines the theory of the sun and the moon to produce a theory that predicts eclipses.

  5. Tychonic system - Wikipedia

    en.wikipedia.org/wiki/Tychonic_system

    In such a system, the Sun, Moon, and stars circle a central Earth, while the five planets orbit the Sun. [16] The essential difference between the heavens (including the planets) and the Earth remained: Motion stayed in the aethereal heavens; immobility stayed with the heavy sluggish Earth. It was a system that Tycho said violated neither the ...

  6. Historical models of the Solar System - Wikipedia

    en.wikipedia.org/wiki/Historical_models_of_the...

    The ancient Hebrews, like all the ancient peoples of the Near East, believed the sky was a solid dome with the Sun, Moon, planets and stars embedded in it. [4] In biblical cosmology, the firmament is the vast solid dome created by God during his creation of the world to divide the primal sea into upper and lower portions so that the dry land could appear.

  7. Solar analog - Wikipedia

    en.wikipedia.org/wiki/Solar_analog

    The Sun is a 4.6 billion year-old G-class (G2V) star and is more massive than 95% of all stars. Only 7.6% are G-class stars. The stars below are more similar to the Sun and having the following qualities: [1] Temperature within 50 K from that of the Sun (5728 to 5828 K) [a] (within 10 K of sun (5768–5788 K)).

  8. Ecliptic - Wikipedia

    en.wikipedia.org/wiki/Ecliptic

    The ecliptic is the apparent path of the Sun throughout the course of a year. [5] Because Earth takes one year to orbit the Sun, the apparent position of the Sun takes one year to make a complete circuit of the ecliptic. With slightly more than 365 days in one year, the Sun moves a little less than 1° eastward [6] every day.

  9. Solar System - Wikipedia

    en.wikipedia.org/wiki/Solar_System

    Thus, the Sun occupies 0.00001% (1 part in 10 7) of the volume of a sphere with a radius the size of Earth's orbit, whereas Earth's volume is roughly 1 millionth (10 −6) that of the Sun. Jupiter, the largest planet, is 5.2 AU from the Sun and has a radius of 71,000 km (0.00047 AU; 44,000 mi), whereas the most distant planet, Neptune, is 30 AU ...