Up until August 24, 2006, the Solar System included the nine planets that kids have been taught and have embraced for decades: Mercury, Venus Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. But on August 24, the International Astronomical Union (IAU), at its General Assembly in Prague, adopted a new definition of ‘planet’ that removed planet status from Pluto.

Read about how you can get a replica of the Voyage Solar System for permanent installation in your community.

Starting about August 28, a makeshift memorial to Pluto appeared at the Pluto unit of the Voyage Scale Model Solar System exhibition on the National Mall in Washington, DC. Visitors to the Smithsonian began leaving condolence cards, love notes, and flowers to mark the passing of Pluto from planet to dwarf planet status. It seems there are a number of folks that don’t like the IAU messing with the ‘family’.

“An article about the Pluto memorial appeared in the Washington Post on September 2, 2006, and was covered in a NCESSE press release.

The IAU is the organization that formally represents the world community of scientists that conducts astronomical research. The IAU defines official nomenclature, and Pluto’s demotion into a new class of object—dwarf planet—means that textbooks will need to be revised.

But that’s the nature of science. As we learn more about the greater universe, in this case the existence of other objects like Pluto, we need to broaden the way we characterize what we know. Pluto’s demotion also means recognition of a new class of Solar System object.

The proceedings in Prague, with over 400 IAU members present, were “intense, highly charged, and dramatic” as reported by Richard G. French, the Chair of the American Astronomical Society’s Division of Planetary Sciences. On the frontiers of science you also find debate and controversy. After all, science is conducted by human beings with a deep emotional investment in uncovering the truth about the universe.

The Voyage exhibition project team is committed to revising the storyboards to reflect current nomenclature, and more importantly, to use the Pluto controversy as a teachable moment regarding the nature of science, the nature of our Solar System, and the nature of ourselves.