Teaching What a Planet Is: A Roundtable on the Educational Implications of the New Definition of a Planet

Abstract

Abstract A quick review of the August 24, 2006, decision by the International Astronomical Union about how todefine a planet in our Solar System is followed by commentary from planetary scientists and educatorsfrom various settings. A table of relevant dates and a list of useful resources are appended, and readers areinvited to participate in the discussion. Preface Readers of the Astronomy Education Review are often the ones on the front lines of our educationalsystem, teaching students, meeting with planetarium and museum audiences, and responding to mediarequests for information. Given all the hoopla about the new definition of a planet in our Solar System bythe International Astronomical Union (IAU) at its meeting in Prague in August 2006, we thought it mightbe interesting to gather a cross-section of reactions from noted astronomy educators and then invite ourreaders to voice their opinions.We begin with a personal report by David Morrison, who was in Prague and served on one of thecommittees that considered the issue of defining a planet. This is followed by comments from OwenGingerich, the chair of the IAU Planet Definition Committee, and a statement from Richard French, thechair of the main organization of planetary astronomers in the United States. We then continue withcommentary from a number of planet experts and several formal and informal educators, including threetextbook authors. (The authors of each comment wrote independently, and there is thus a small amount ofoverlap in their comments that we have left in when needed for clarity.)