Shop Windows to the Universe

Dig into Montana Before History: 11K Years of Hunter-Gatherers in the Rockies and Plains by D. H. MacDonald, Ph.D. See our online store book collection.
Picture of Giovanni Cassini
Corbis-Bettmann

Giovanni Cassini

Giovanni Cassini was Italian-French astronomer who lived between 1625-1712. He discovered that Saturn's Rings are split into two parts, and today the gap between them is called the "Cassini Division". He also discovered four of Saturn's moons, in addition to those found by Huygens twenty years earlier.

Cassini studied hydrology and how to avoid the damaging floods that plagued Europe. His greatest mistakes were rejecting the Copernican model of the solar system and Newton's theory of universal gravitation.

Shop Windows to the Universe Science Store!

Our online store includes issues of NESTA's quarterly journal, The Earth Scientist, full of classroom activities on different topics in Earth and space science, as well as books on science education!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Science, Evolution, and Creationism

How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more

Christian Huygens

Christian Huygens was a Dutch physicist and astronomer who lived between 1629-1695. He found new methods for grinding and polishing lenses, making telescopes more powerful. Using a telescope he had made,...more

Nicholas Copernicus

Nicholas Copernicus was a Polish astronomer who lived between 1473-1543. Before his time, people believed in the Ptolemaic model of the solar system, which maintained that the Earth was the center of...more

Isaac Newton

Isaac Newton was an English scientist and mathematician who lived between 1642-1727. He had one of the most brilliant minds the world has ever known. Legend has it that seeing an apple fall gave Newton...more

Charles Darwin

Charles Darwin was an English Naturalist who lived between 1809-1882. He laid the foundations for the modern science of biology, and changed how other scientists understood the appearance of life on Earth....more

Christian Doppler

Christian Doppler was an Austrian mathematician who lived between 1803-1853. He is known for the principle he first proposed in Concerning the coloured light of double stars in 1842. This principle is...more

Ben Franklin

Ben Franklin was an American scientist and statesman who lived between 1706-1790. At a time when little was known about electricity, he carried out many experiments to learn of its dangers and possible...more

Edmond Halley

Edmond Halley was an English astronomer who lived between 1656-1742. Using historical records, his own observations, and Newton's universal law of gravitation, he reasoned that the comets which had appeared...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF