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Article: Plutos galore: ice dwarfs may dominate the solar system's planetary population. (Cover Story)
- Article from:
- Science News
- Article date:
- September 21, 1991
- Author:
CopyrightCOPYRIGHT 1991 Science Service, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Ask most fifth-graders about the solar system and they'll tell you it consists of the sun and nine planets. Some may even know that the solar system formed about 5 billion years ago from a disk of dust surrounding the young sun. As gravity lumped the dust particles together, some formed chunks called comets. A few of the lumps grew bigger, developing into the planets--first Saturn and the other orbs nearer the sun, and later the icy spheres of Uranus, Neptune and Pluto.
This account reflects the thinking of most astronomers. But S. Alan Stern wants to revise the textbook notion about the number of planets and how they formed.
The outhermost three of ...