In the 19th century, astronomers believed that solar systems formed in nebular clouds throughout the universe. But 20th century scientists rejected that idea, arguing that our solar system was an ...

THIS book, which appeared on the author's eighty-fifth birthday, and less than two months before his lamented death, is a summary of the well-known planetesimal hypothesis of the origin of the solar ...

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...