Cosmic Horizons

Profile: Vera Rubin and Dark Matter

Online Resource, Article

Profile: Vera Rubin and Dark Matter

For every visible star in the observable universe, there are nine masses that are invisible and unidentified. Learn more about the astronomer who proved the existence of dark matter.

Profile: Lyman Spitzer and the Space Telescope

Online Resource, Article

Profile: Lyman Spitzer and the Space Telescope

The idea of launching a telescope into orbit was first suggested in 1923, but the idea wasn't realized until nearly 70 years later. Along the way, there were several obstacles and setbacks.

Profile: Fritz Zwicky's Extraordinary Vision

Online Resource, Article

Profile: Fritz Zwicky's Extraordinary Vision

Astronomer Fritz Zwicky was the first person to conceive of supernovas, neutron stars, dark matter, and gravitational lenses. So why don't more people know his name?

Profile: Harold C. Urey

Online Resource, Article

Profile: Harold C. Urey

This Nobel Prize–winning chemist contributed to several scientific fields. His remarkable body of work spanned chemistry, geochemistry, lunar science, and astrochemistry.

SELECT PAGE