https://www.khanacademy.org/science/shs-physical-science/x0492729e402f0c6b:4th-quarter/x0492729e402f0c6b:evolving-models-of-the-universe/a/the-geocentric-universe 2021-04-29T07:58:59Z The geocentric universe article https://www.khanacademy.org/science/als-k-to-12-science/x46c2fc9f8e023990:4th-quarter/x46c2fc9f8e023990:characteristics-of-stars-understanding-stars-based-on-the-sun/v/watch-unit-3-overview-big-history-project 2026-04-15T09:00:48.368849752Z History of Astronomy In this video our fearless narrator Rachel Hansen turns our gaze on the Stars and Elements that came into being before our planet existed. We will see how our collective learning over the last few millennia allowed us humans to gain some understanding of these long ago, far away events. Like what you see? This video is part of a comprehensive social studies curriculum from OER Project, a family of free, online social studies courses. OER Project aims to empower teachers by offering free and fully supported social studies courses for middle- and high-school students. Your account is the key to accessing our standards-aligned courses that are designed with built-in supports like leveled readings, audio recordings of texts, video transcripts, and more. Register today at oerproject.com! Website: https://www.oerproject.com/Big-History Facebook: https://www.facebook.com/OERProject Twitter: https://www.twitter.com/oerproject/ Big History Project video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw History of Astronomy In this video our fearless narrator Rachel Hansen turns our gaze on the Stars and Elements that came into being before our planet existed. We will see how our collective learning over the last few millennia allowed us humans to gain some understanding of these long ago, far away events. Like what you see? This video is part of a comprehensive social studies curriculum from OER Project, a family of free, online social studies courses. OER Project aims to empower teachers by offering free and fully supported social studies courses for middle- and high-school students. Your account is the key to accessing our standards-aligned courses that are designed with built-in supports like leveled readings, audio recordings of texts, video transcripts, and more. Register today at oerproject.com! Website: https://www.oerproject.com/Big-History Facebook: https://www.facebook.com/OERProject Twitter: https://www.twitter.com/oerproject/ https://cdn.kastatic.org/ka-youtube-converted/zR2YX1T61Ds.mp4/zR2YX1T61Ds.mp4 566 Universe: geocentric or heliocentric https://www.khanacademy.org/science/middle-school-earth-and-space-science/x87d03b443efbea0a:earth-in-space/x87d03b443efbea0a:earths-place-in-the-universe/v/earths-place-in-the-universe 2024-01-04T21:44:22.995765104Z Earth's place in the universe Humans have used models to understand Earth's place in the universe. The geocentric model, placing Earth at the center, was replaced by the heliocentric model, with the sun at the center. This change better explains the movement of celestial bodies and shows that Earth's rotation causes the sun's apparent motion. Khan Academy video https://cdn.kastatic.org/ka_thumbnails_cache/367f5f88-2954-4708-a8a2-1ea2aa569771_1280_720_base.png Earth's place in the universe Humans have used models to understand Earth's place in the universe. The geocentric model, placing Earth at the center, was replaced by the heliocentric model, with the sun at the center. This change better explains the movement of celestial bodies and shows that Earth's rotation causes the sun's apparent motion. https://cdn.kastatic.org/ka-youtube-converted/Pv0Re0YEEq0.mp4/Pv0Re0YEEq0.mp4 294 Universe: geocentric or heliocentric https://www.khanacademy.org/science/middle-school-earth-and-space-science/x87d03b443efbea0a:earth-in-space/x87d03b443efbea0a:earths-place-in-the-universe/a/earths-place-in-the-universe 2025-08-13T04:01:09.814076401Z Earth’s place in the universe Review your understanding of Earth's place in the universe in this free article aligned to NGSS standards. article https://www.khanacademy.org/science/middle-school-earth-and-space-science/x87d03b443efbea0a:earth-in-space/x87d03b443efbea0a:earths-place-in-the-universe/e/understand-earths-place-in-the-universe 2026-03-11T01:50:44.937458787Z Understand: Earth's place in the universe Check your understanding of Earth's place in the universe in this set of free practice questions aligned to NGSS standards. Lauren Rosebrugh exercise