Poor Pluto once a planet and now a lowly ice ball. Actually, Pluto is now a "dwarf planet." Another term for dwarf planet might be "almost-planet." So what exactly is a planet?
A few years ago, scientists at a meeting took a good look at Pluto. They asked whether Pluto was a true planet. They decided that it wasn't, after all. These same scientists came up with a new definition of planet that most of them can agree on. A true planet is an object that goes around the sun. It has to be large enough to have a round shape. This shape is caused by the force of its own gravity. It also has to be far larger than the other bodies orbiting around it.
Pluto orbits the sun and is round, but it isn't much bigger than its own moons. Also, true planets clear a path along their orbit. It's as if they're sweeping away comets, asteroids, and other objects in their journey. Pluto has lots of rubbish in its path.
For these reasons, poor Pluto was demoted and is no longer a planet. See what happens when you don't keep the area around you tidy?
1.What is the main idea of the passage?
A. You should always clean up your messes.
B. The solar system is made up of different planets.
C. Pluto is no longer considered a planet.
D. Pluto is not much bigger than its moons.
2. What is one reason scientists decided Pluto is not a true planet?
A. It does not have a round shape.
B. It does not have any gravity.
C. It does not clear a path on its orbit.
D. It does not orbit its moons.
3.Why does the author say "poor Pluto"?
A. Pluto is trashy.
B. Pluto is cold
C. Pluto is no longer a planet.
D. Pluto does not orbit the sun.
4.What can you conclude after reading this passage?
A. Gravity causes planets to be round.
B. Pluto does not have much space trash in its orbit.
C. All planets have moons that orbit around them.
D. Comets and asteroids orbit Pluto.
1. C. Pluto is no longer considered a planet.
2. C. It does not clear a path on its orbit.
3. C. Pluto is no longer a planet.
4. A. Gravity causes planets to be round.
1. The main idea of the passage is C. Pluto is no longer considered a planet.
2. One reason scientists decided Pluto is not a true planet is C. It does not clear a path on its orbit.
3. The author says "poor Pluto" because C. Pluto is no longer a planet.
4. Based on the passage, you can conclude that D. Comets and asteroids orbit Pluto.