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Our Glaciers: Then and Now activity kit helps you see the changes taking place in glaciers around the world. See all our activity kits and classroom activities.

Simon Marius

Simon Marius was a German astronomer who lived between 1573-1624. He made observations of the heavens with a telescope, and every year, he published tables of the locations of the stars and planets. Although Marius named the four moons of Jupiter, it is believed that Galileo discovered them first.

Due to his strong religious beliefs, Marius never accepted the Copernican model of the universe.

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Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

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Science, Evolution, and Creationism

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Galileo Galilei

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Nicholas Copernicus

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Tycho Brahe

Tycho Brahe was a Danish astronomer who lived between 1546-1601. For over twenty years he made observations of stars, comets, and planets in the night sky. Tycho also built the first observatory but did...more

Leonardo da Vinci

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Johan Kepler

Johan Kepler was a German astronomer who lived between 1571-1630. Kepler used Tycho Brahe's observations of Mars to show that planetary orbits are not circular, but, in fact, elliptical (or shaped like...more


Archimedes was a Greek mathematician and engineer who lived between 287-212 B.C. His greatest contributions are in the field of geometry, where he did much work with circles and their properties. Legend...more


Aristotle was a Greek philosopher who lived between 384-322 B.C. He was one of the greatest thinkers of the world and wrote on every major area of thought. Aristotle thought that the Earth was at the...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA