July 9-22, 2015 Current Events Lesson Plan
Current Event: Pluto Dazzles in First Close-Up
The New Horizons probe, launched by the United States National Aeronautics and Space Administration (NASA), recently made its closest approach to the dwarf planet Pluto. The first images taken by the probe found that Pluto is a world of giant mountains, mysteriously clean surfaces, and other wonders. One image shows mountains rising up to 11,000 feet (3,400 meters) above the surrounding surface, comparable in height to the Rocky Mountains on Earth. Scientists were amazed by a relative lack of impact craters in the images. Such craters tend to build up over time as planets and other bodies are bombarded by chunks of rock and ice. Since Pluto is thought to be the same age as the rest of the solar system some process must be erasing craters, rejuvenating the planet’s surface. It will take about 16 months for the New Horizons spacecraft to send back all the data it has gathered on its nearly 10-year mission.
Objective:
Pluto is a dwarf planet that orbits far from the sun. Astronomers know little about the dwarf planet because it is so far away from Earth and is relatively small. In 1930, Clyde W. Tombaugh, an assistant at the Lowell Observatory in Arizona, discovered Pluto. From 1930 until 2006, Pluto was widely considered the ninth planet of our solar system. However, in 2006, the International Astronomical Union (IAU) reclassified it as a dwarf planet. Pluto’s average distance from the sun is about 40 times that of Earth. It takes Pluto about 248 years to make one orbit around the sun. Pluto has five known moons: Charon, Hydra, Kerberos, Nix, and Styx. The Behind the Headlines news story and related World Book articles explore Pluto and other astronomical topics.
Words to know:
- Astronomy
- Clyde William Tombaugh
- Dwarf planet
- Hubble Space Telescope
- National Aeronautic and Space Administration (NASA)
- New Horizons
- Pluto
- Solar system
- Space exploration
Discussion Topics:
1. Pluto and the other four recognized dwarf planets orbit the sun. Ask your students if they know any other types of celestial bodies that orbit the sun. (They might say the eight planets; some comets, including Halley’s Comet; occasional meteors; asteroids.)
2. Ask your students to debate “One day we will find intelligent life on another planet.”
3. In 2006, the International Astronomical Union (IAU) reclassified Pluto as a dwarf planet. Have your students read World Book’s “Solar system,” “Pluto,” and “Planet” articles. After reading, ask your students to debate whether Pluto should still be classified as a planet.
4. Ask your students to use World Book’s Timelines feature to view or add to the Advances in Space Exploration timeline. (Students may wish to use World Book’s Space exploration article for help.)