What Is a Planet?

07.21.09

This seemingly simple question doesn't have a simple answer. 

Scientists are not in agreement about a newly discovered object "Pandora" if it is a planet or not. We will take part in the conversation by exploring Pandora. debate similar to the one held by the IAU. They debate whether "Pandora," a fictional solar system object discovered by NASA's New Horizons spacecraft, is a planet. 

 

 Most of us know that Earth, Mars and Jupiter are planets. For many years, Pluto was considered a planet too. But astronomers began to question Pluto's planetary status when they started to find celestial bodies near Pluto that were similar to its size.

In 2006, astronomers at a meeting of the International Astronomical Union, known as the IAU, debated whether Pluto is a planet or not. Suddenly, the solar system was down to eight planets instead of nine. Pluto was demoted to a "dwarf planet." 

Resource: http://www.nasa.gov/audience/foreducators/9-12/features/what-is-a-planet.html

Let us plan how we are going to approach our exploration mission. replay to this post to discuss our plan.

#1: Before we start: how much do you know about the solar system?

Before we start, to determine how much you know about the solar system, take this quiz. (no points but I encourage you to do a self-assessment of your knowledge before you start)

Test your knowledge

If a student fails to answer some of the questions, he/shecan review the main definitions and concepts required for the class using the flashcards and activities attached to the quiz.