Current Event:

The name “Vulcan” was a surprise co-winner in the “Pluto Rocks” online contest in which the public was asked to help choose names for two moons recently discovered orbiting Pluto. In 2011 and 2012, astronomers with the SETI Institute, a research organization that searches for life in the universe beyond Earth, discovered the two moons in 2011 and 2012 using the Hubble Space Telescope. The SETI astronomers gave the public a chance to help pick the name for the moons. The ballot included 12 names from Greek and Roman mythology associated with Hades, the land of the dead. “Vulcan,” which was not on the original ballot, was a write-in candidate suggested by actor William Shatner, who starred in the “Star Trek” science-fiction television and film series. The SETI scientists agreed to add “Vulcan” to the ballot. “Vulcan” collected 174,062 of the 450,324 votes cast. “Cerberus,” the name of the three-headed dog that guarded the entrance to the underworld in Greek and Roman mythology, came in second, with nearly 100,000 votes.

Canadian-born actor William Shatner gained fame as Captain James T. Kirk, commander of the starship U.S.S. Enterprise in the television science-fiction series "Star Trek" (1966-1969). (© Paramount/The Kobal Collection)

Objective:

Pluto is a dwarf planet that orbits the sun. Astronomers know little about Pluto 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. In 2006, the International Astronomical Union (IAU) reclassified Pluto as a dwarf planet. Pluto was demoted to dwarf planet status, in part, because it is not massive enough for its gravitational pull to sweep the region of its orbit relatively free of other objects. In 1978, astronomers detected a satellite of Pluto, which they named Charon. In 2005, astronomers studying Hubble Space Telescope images found two new moons of Pluto, later named Hydra and Nix. The Behind the Headlines news story  and related World Book articles explore Pluto and other astronomical topics.

Words to know:
•    Astronomy
•    Cerberus
•    Dwarf planet
•    Hades
•    Hubble Space Telescope
•    Planet
•    Pluto
•    Satellite
•    SETI Institute
•    William Shatner
•    Star Trek
•    Clyde William Tombaugh
•    Vulcan

Discussion Topics:

1. Ask your students if they know the names of the eight planets in our solar system. (They should say Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.) See if your student can come up with a mnemonic for remembering the names of the planets.
2. Astronomy is the study of the universe and the objects in it. Have your students debate the topic, “It is important to study astronomy.”
3. Have your students read World Book’s “Solar System” 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 the World Book’s Timelines feature to create a timeline of discoveries about and the exploration of Pluto. (Students may wish to use World Book’s Pluto article to find information for the timeline.)