Pluto: A Dwarf Planet's Story
Pluto: A Dwarf Planet's Story
Once upon a time, people thought there were nine planets in our solar system. One of those planets, way out past Neptune, was Pluto. For many years, Pluto was known as the ninth planet. But things changed, and now Pluto is called a dwarf planet.
What is a Dwarf Planet?
A dwarf planet is like a planet, but it doesn't quite fit all the rules. To be a planet, a celestial body has to orbit the Sun, be round or nearly round, and clear its orbit of other objects. Pluto orbits the Sun and is round. However, Pluto hasn't cleared its orbit. This means there are other space rocks and objects floating around in the same area as Pluto.
Discovering Pluto
Pluto was discovered in 1930 by Clyde Tombaugh. He was an astronomer working at the Lowell Observatory. When Pluto was found, it seemed to fit the description of a planet. It was very far away, very cold, and very mysterious. For a long time, it was hard to learn much about Pluto because it was so distant.
Why Pluto is Special
- Dwarf Planet:
- A celestial body that orbits the Sun, is round, but hasn't cleared its orbit of other objects.
- Orbit:
- The path an object takes around another object in space.
- Astronomer:
- A scientist who studies space, including planets, stars, and galaxies.
- Glacier:
- A large mass of ice that moves slowly over land.
- celestial body:
- A natural object located out in space, such as a planet, moon, asteroid, or star.
- spacecraft:
- A vehicle or machine designed to travel and work in outer space beyond Earth's atmosphere.
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Preview questions from this passageShowHide
- 1What is Pluto now called?
- 2What are the three rules for being a planet?
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About this informational passage for Upper Elementary
“Pluto: A Dwarf Planet's Story” is a informational reading passage about Pluto, written for Upper Elementary. It takes about 2 minutes to read (339 words) and comes with an interactive quiz and a printable worksheet with comprehension questions and an answer key.