On August 24, 2006, a group of astronomers made a big announcement: Pluto could no longer be considered a planet. This book explains how advancements in technology have changed our understanding of the universe--and exactly how and why the number of planets in our solar system went from nine to eight.

Describes Pluto, which was officially designated a dwarf planet in 2006.

"Hot diggity dog! Meet Pluto! The runt of a litter of eight planets. Pluto may not be the biggest or fastest planet to revolve around the Sun, but it has a unique story to tell. From the tale of how it was found by humans to its naming as a dwarf planet, it's Pluto's turn to take the spotlight and properly re-introduce itself."--Publisher marketing.

When Stink discovers that Pluto has been downgraded from a planet to a dwarf planet, he launches a campaign in his classroom to restore its status to that of a full-fledged member of the solar system.

Infuriated by the declaration that Pluto is no longer a planet, President Penguin and his penguins invade Earth and it is up to Ricky and his robot pal to defeat them--with some help from Ricky's cousin Lucy and her pets.

Describes the discovery and observation of the ninth planet, Pluto, and what has been learned about its orbit, its makeup, and its moon.

In this creative nonfiction work, just after learning that Earth's scientists no longer consider him a planet, an unhappy Pluto takes a visitor from Earth on a tour of the solar system, sharing facts along the way.

"Orbiting at the edge of the outer Solar System, Pluto is an intriguing object in astronomy. Since the fascinating events surrounding its discovery, it has helped increase our understanding of the origin and evolution of the Solar System, and raised questions about the nature and benefits of scientific classification. This is a timely and exciting account of Pluto and its satellites. The author uses Pluto as a case study to discuss discovery in astronomy,...