Editing Astronomy (section)

=== Early telescopic astronomy ===
[[File:Galileo's sketches of the moon.png|thumb |upright |The first sketches of the Moon's topography, from [[Galileo]]'s ground-breaking ''[[Sidereus Nuncius]]'' (1610), publishing his findings from the first telescopic astronomical observations.]]

During the [[Renaissance]], [[Nicolaus Copernicus]] proposed a heliocentric model of the solar system. His work was defended by [[Galileo Galilei]] and expanded upon by [[Johannes Kepler]]. Kepler was the first to devise a system that correctly described the details of the motion of the planets around the Sun. However, Kepler did not succeed in formulating a theory behind the laws he wrote down.<ref>{{harvnb|Forbes|1909|pp=49–58}}</ref> It was [[Isaac Newton]], with his invention of [[celestial dynamics]] and his [[gravity|law of gravitation]], who finally explained the motions of the planets. Newton also developed the [[reflecting telescope]].<ref name="f58-64">{{harvnb|Forbes|1909|pp=58–64}}</ref>

Improvements in the size and quality of the telescope led to further discoveries. The English astronomer [[John Flamsteed]] catalogued over 3000 stars.<ref>Chambers, Robert (1864) ''[[Chambers Book of Days]]''</ref> More extensive star catalogues were produced by [[Nicolas Louis de Lacaille]]. The astronomer [[William Herschel]] made a detailed catalog of nebulosity and clusters, and in 1781 discovered the planet [[Uranus]], the first new planet found.<ref>{{harvnb|Forbes|1909|pp=79–81}}</ref>

During the 18–19th centuries, the study of the [[three-body problem]] by [[Leonhard Euler]], [[Alexis Claude Clairaut]], and [[Jean le Rond d'Alembert]] led to more accurate predictions about the motions of the Moon and planets. This work was further refined by [[Joseph-Louis Lagrange]] and [[Pierre Simon Laplace]], allowing the masses of the planets and moons to be estimated from their perturbations.<ref>{{harvnb|Forbes|1909|pp=74–76}}</ref>

Significant advances in astronomy came about with the introduction of new technology, including the [[spectroscope]] and [[Astrophotography|photography]]. [[Joseph von Fraunhofer]] discovered about 600 bands in the spectrum of the Sun in 1814–15, which, in 1859, [[Gustav Kirchhoff]] ascribed to the presence of different elements. Stars were proven to be similar to the Earth's own Sun, but with a wide range of [[temperature]]s, [[mass]]es, and sizes.<ref name="short history" />