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Orion Nebula is discovered
Nicholas-Claude Fabri de Peiresc discovers the Orion Nebula, a cloud of dust out in space. At the time of its discovery, its distance from Earth was not measured in light years, however, it is now measured as 1500 light years away.
Hubblesite.org. The Orion Nebula. Digital image. Red Orbit. Redorbit.com, 2013. Web. 12 Dec. 2013.
"Orion Nebula." Red Orbit. Redorbit.com, 2013. Web. 12 Dec. 2013. -
Light is given definite speed
Ole Christensen Romer proved light has a definite speed. This led to the need of a unit to express bigger units of time/distance. Jaggard, Victoria. "A Brief History of Light-Years." National Geographic. National Geographic Society, 22 Nov. 2012. Web. 12 Dec. 2013.
Ole Christensen Römer. Digital image. UCoz, n.d. Web. 12 Dec. 2013. http://bourabai.narod.ru/roemer/. -
Distance between Earth and star is calculated
Friedrich Wilhelm Bessel is the first person to calculate the distance betweeen Earth and a star other than the Sun. The need for a bigger unit of distance/time became even more necessary. Jaggard, Victoria. "A Brief History of Light-Years." National Geographic. National Geographic Society, 22 Nov. 2012. Web. 12 Dec. 2013.
Friedrich Wilhelm Bessel. Digital image. Elite Astronomy. UCoz, n.d. Web. 12 Dec. 2013. http://elite-astronomy.narod.ru/ast_105.htm. -
Light Years are born!
Friedrich Wilhelm Bessel, soon after his calculation of the distance between a star (other than the Sun) and Earth, converts the standard unit of Cigni to light years. This new unit of distance and time refers to, according to National Geographic, as the distance light travels in a vaccum in one year. This was a larger-scale unit, making astronomy calculations much easier.
Jaggard, Victoria. "A Brief History of Light-Years." National Geographic. National Geographic Society, 22 Nov. 2012. Web. 1 -
Milky Way is 10,000 light-years across
At this point in history, scientists believed that the Milky-Way Galaxy was 10,000 light-years across. "Milky Way galaxy." World of Scientific Discovery. Gale, 2007. Science in Context. Web. 12 Dec. 2013.
"Milky Way." Digital image. Astronomy & Space: From the Big Bang to the Big Crunch. Gale, 2010. Science in Context. Web. 12 Dec. 2013. -
Sun in relation to the Milky Way
Also in cerca 1950, Harrow Shapley found that the Sun is 50,000 light-years away from the center of the Milky Way. "Milky Way galaxy." World of Scientific Discovery. Gale, 2007. Science in Context. Web. 12 Dec. 2013.
Caltech. Map of the Milky Way. Digital image. Universe Today. N.p., 16 Sept. 2008. Web. 12 Dec. 2013. -
New Milky Way diameter
Cerca 1950, Harlow Shapley, an astronomer, made the discovery that the Milky Way was much greater than the previously-believed diameter of 10,000 light-years. Shapley's work concluded that the Milky Way was 300,000 light-years across.
"Milky Way galaxy." World of Scientific Discovery. Gale, 2007. Science in Context. Web. 12 Dec. 2013.
"Milky Way." Digital image. Astronomy & Space: From the Big Bang to the Big Crunch. Gale, 2010. Science in Context. Web. 12 Dec. 2013. -
Milky Way is downsized
Jan Hendrik Oort, a Dutch astronomer, was able to show that the Milky Way isn't in fact as big as believed. In cerca 1960, he calculated the diameter of the Milky Way to be 100,000 light-years, the thickness to be 2,000 light-years, and the sun to be 30,000 light-years away from the center of the Milky Way.
"Milky Way galaxy." World of Scientific Discovery. Gale, 2007. Science in Context. Web. 12 Dec. 2013.
Oort, Prof. Jan Hendrik Oort. Digital image. The Bruce Medalists. JST, 29 Sept. 2013. Web
