Part of Hall of the Universe.
AMNH/D. Finnin Until the end of the 20th century, ours was the only planetary system known. We now know of more planets outside our solar system than within it. These observations show the diversity of planetary systems and inspire new ideas about how planets form and evolve. Most important, they indicate that planets are common in the universe.
Diversity of Planetary Systems
Until the end of the 20th century, ours was the only planetary system known. We now know of more planets outside our solar system than within it. These observations show the diversity of planetary systems and inspire new ideas about how planets form and evolve. Most important, they indicate that planets are common in the universe.