Uploaded June 2022 | Updated September 2026, 3 weeks ago

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For most of human history, we didn't know that galaxies were a thing. So over the past century, astronomers have been working to understand how galaxies come to be and how they evolve over time. And for a full decade, there was one telescope helping to light the way.

Hosted By: Hank Green
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Sources:
https://ned.ipac.caltech.edu/level5/March01/Marcum/Marcum2.html
https://astronomy.swin.edu.au/cosmos/m/main+sequence+lifetime
britannica.com/science/red-dwarf-star
http://www.galex.caltech.edu/media/glx2004-01r_img06.html
http://www.galex.caltech.edu/about/overview.html
http://www.galex.caltech.edu/newsroom/glx2007-01f.html
http://www.galex.caltech.edu/newsroom/glx2007-05f.html
http://www.galex.caltech.edu/newsroom/glx2009-01r.html
http://www.galex.caltech.edu/newsroom/glx2010-03f.html
http://www.galex.caltech.edu/newsroom/glx2013-03r.html
jpl.nasa.gov/news/press_kits/galex.pdf
asd.gsfc.nasa.gov/archive/galex/Documents/MissionOverview.html
nasa.gov/content/hubble-space-telescope-advanced-camera-for-surveys
iopscience.iop.org/issue/0067-0049/173/2

Images:
commons.wikimedia.org/wiki/File:Swimming_in_Sculptor.jpg
commons.wikimedia.org/wiki/File:GALEX_spacecraft_model.png
gettyimages.com/detail/photo/night-sky-with-stars-and-soft-milky-way-universe-as-royalty-free-image/971578384?adppopup=true
gettyimages.com/detail/illustration/set-of-electromagnetic-spectrum-diagram-or-royalty-free-illustration/1311362176?adppopup=true
gettyimages.com/detail/photo/blue-hot-sun-royalty-free-image/157505921?adppopup=true
commons.wikimedia.org/wiki/File:Morgan-Keenan_spectral_classification.png
flickr.com/photos/gsfc/3927825968
commons.wikimedia.org/wiki/File:Atmospheric_Transmission.png
commons.wikimedia.org/wiki/File:GALEX_Pegasus.jpg
http://www.galex.caltech.edu/media/glx2005-02r_img08.html
commons.wikimedia.org/wiki/File:GALEX_Field_of_View.jpg
http://www.galex.caltech.edu/media/glx2016-01f_img01.html
nasa.gov/multimedia/imagegallery/image_feature_972.html
http://www.galex.caltech.edu/media/glx2007-05f_img02.html
http://www.galex.caltech.edu/media/glx2007-05f_img05.html
commons.wikimedia.org/wiki/File:Abell_S740,_cropped_to_ESO_325-G004.jpg
http://www.galex.caltech.edu/media/glx2007-05f_img01.html
nasa.gov/mission_pages/galex/big-brother-milky-way.html
http://www.galex.caltech.edu/media/glx2004-01r_img06.html
commons.wikimedia.org/wiki/File:Galaxy_cluster_PLCK_G004.5-19.5_A_window_into_the_cosmic_past.jpg
commons.wikimedia.org/wiki/File:MACSJ1423.8%2B2404.jpg
nasa.gov/mission_pages/galex/galex20100811.html
commons.wikimedia.org/wiki/File:NGC4676.jpg
commons.wikimedia.org/wiki/File:Galaxy_Evolution_Explorer,_2003.jpg