5th century BC – Democritus proposes that the bright band in the night sky known as the Milky Way might consist of stars. 4th century BC – Aristotle believes the Milky Way to be caused by "the ignition of the fiery exhalation of some stars which were large, numerous and close together" and that the "ignition takes place in the upper part of the atmosphere, in the region of the world which is continuous with the heavenly motions". 964 – Abd al-Rahman al-Sufi (Azophi), a Persian astronomer, makes the first recorded observations of the Andromeda Galaxy and the Large Magellanic Cloud in his Book of Fixed Stars, and which are the first galaxies other than the Milky Way to be recorded. 11th century – Al-Biruni, another Persian astronomer, describes the Milky Way galaxy as a collection of fragments of numerous nebulous stars. 11th century – Alhazen (Ibn al-Haytham), an Arabian astronomer, refutes Aristotle's theory on the Milky Way by making the first attempt at observing and measuring the Milky Way's parallax, and he thus "determined that because the Milky Way had no parallax, it was very remote from the Earth and did not belong to the atmosphere". 12th century – Avempace (Ibn Bajjah) of Islamic Spain proposes the Milky Way to be made up of many stars but that it appears to be a continuous image due to the effect of refraction in the Earth's atmosphere. 14th century – Ibn Qayyim al-Jawziyya of Syria proposes the Milky Way galaxy to be "a myriad of tiny stars packed together in the sphere of the fixed stars", and that these stars are larger than planets. 1521 – Ferdinand Magellan observes the Magellanic Clouds during his circumnavigating expedition. 1610 – Galileo Galilei uses a telescope to determine that the bright band on the sky, the "Milky Way", is composed of many faint stars. 1612 – Simon Marius using a moderate telescope observes Andromeda and describes as a "flame seen through horn". 1750 – Thomas Wright discusses galaxies and the flattened shape of the Milky Way and speculates nebulae as separate. 1755 – Immanuel Kant drawing on Wright's work conjectures that our galaxy is a rotating disk of stars held together by gravity, and that the nebulae are separate such galaxies; he calls them Island Universes. 1774 – Charles Messier releases a preliminary list of 45 Messier objects, three of which turn out to be the galaxies including Andromeda and Triangulum. By 1781 the final published list grows to 103 objects, 34 of which turn out to be galaxies. 1785 – William Herschel carried the first attempt to describe the shape of the Milky Way and the position of the Sun in it by carefully counting the number of stars in different regions of the sky. He produced a diagram of the shape of the galaxy with the solar system close to the center. 1845 – Lord Rosse discovers a nebula with a distinct spiral shape.
5th century BC – Democritus proposes that the bright band in the night sky known as the Milky Way might consist of stars. 4th century BC – Aristotle believes the Milky Way to be caused by "the ignition of the fiery exhalation of some stars which were large, numerous and close together" and that the "ignition takes place in the upper part of the atmosphere, in the region of the world which is continuous with the heavenly motions". 964 – Abd al-Rahman al-Su!fi (.Azophi), a Persian astronomer, makes the first recorded observations of the Andromeda Galaxy and the Large Magellanic Cloud in his Book of Fixed Stars, and which are the first galaxies other than the Milky Way to be recorded. 11th century – Al-Biruni, another Persian astronomer, describes the Milky Way galaxy as a collection of fragments of numerous nebulous stars. 11th century – Alhazen (Ibn al-Haytham), an Arabian astronomer, refutes Aristotle's theory on the Milky Way by making the first attempt at observing and measuring the Milky Way's parallax, and he thus "determined that because the Milky Way had no parallax, it was very remote from the Earth and did not belong to the atmosphere". 12th century – Avempace (Ibn Bajjah) of Islamic Spain proposes the Milky Way to be made up of many stars but that it appears to be a continuous image due to the effect of refraction in the Earth's atmosphere. 14th century – Ibn Qayyim al-Jawziyya of Syria proposes the Milky Way galaxy to be "a myriad of tiny stars packed together in the sphere of the fixed stars", and that these stars are larger than planets. 1521 – Ferdinand Magellan observes the Magellanic Clouds during his circumnavigating expedition. 1610 – Galileo Galilei uses a telescope to determine that the bright band on the sky, the "Milky Way", is composed of many faint stars. 1612 – Simon Marius using a moderate telescope observes Andromeda and describes as a "flame seen through horn". 1750 – Thomas Wright discusses galaxies and the flattened shape of the Milky Way and speculates nebulae as separate. 1755 – Immanuel Kant drawing on Wright's work conjectures that our galaxy is a rotating disk of stars held together by gravity, and that the nebulae are separate such galaxies; he calls them Island Universes. 1774 – Charles Messier releases a preliminary list of 45 Messier objects, three of which turn out to be the galaxies including Andromeda and Triangulum. By 1781 the final published list grows to 103 objects, 34 of which turn out to be galaxies. 1785 – William Herschel carried the first attempt to describe the shape of the Milky Way and the position of the Sun in it by carefully counting the number of stars in different regions of the sky. He produced a diagram of the shape of the galaxy with the solar system close to the center. 1845 – Lord Rosse discovers a nebula with a distinct spiral shape.