At July’s “Pluto System After New Horizons” conference, held at the Johns Hopkins University Applied Physics Laboratory (JHUAPL) in Laurel, Maryland, professional papers presented by scientists drove home the fact that 13 years after the controversial IAU planet definition vote, more and more people view Pluto as a planet.
While many presenters used the term “planet” in reference to Pluto, that was hardly necessary, as the data spoke for itself—varied, complex surface terrains, the makeup of the layers that comprise Pluto’s atmosphere, and the origin of the solar system. I was fortunate to attend some of the sessions and hope to provide a more detailed discussion of each topic in future blog entries.
Meanwhile, Astronomy magazine’s September issue features Pluto, along with Jupiter’s moon Europa, Saturn’s moons Titan and Enceladus, Neptune’s moon Triton, and Mars, on the front cover as prime solar system locations that could host microbial life.
Over time, more and more people are viewing these images and reading articles like this one and coming to realize on their own that the planet definition adopted 13 years ago today by the IAU is highly flawed and blatantly wrong in considering dwarf planets to not be planets at all. While the IAU continues to refuse to revisit the issue, its definition is clearly losing ground.
Even media coverage of the debate is improving. While still problematic, an article published today by CNN at least makes an attempt to acknowledge that this is an ongoing debate with two legitimate sides, as is evident from its title, “Why Pluto is no longer a planet (or is it?).” Putting the question “is it” in parentheses diminishes the pro-Pluto side, implying just a small number of scientists reject the IAU definition, when this is far from the case. To really be fair, the title should give equal standing to both positions.
Several sections of the article are problematic in terms of words and phrases used. The writer continues to push the erroneous view that only the IAU has the right to determine what is and is not a planet. This can be seen from sentences such as "Pluto was relegated in 2006 when the International Astronomical Union (IAU) created a new definition for planets and decided Pluto did not fit the bill."
She goes on to say that August 24 has been dubbed “Pluto Demotion Day,” a term I have never heard used and one likely to come from Mike Brown, whom she erroneously describes as the sole discoverer of Eris. She may be repeating his statement without questioning it, something a good journalist should do.
The Brown-friendly wording continues with statements such as “The final blow came in 2003,” “And then there were eight,” and “Brown is dubbed the man who killed Pluto” complete with a link to his website. The truth is that Brown is not "dubbed the man who killed Pluto." He dubbed himself that; the sentence erroneously makes it sound like everyone else did this when that is not the case. He did this as a gimmick, most likely to sell books and pursue money and fame.
Just as important are the things she does not say. Nowhere does she acknowledge that that only four percent of the IAU voted on this; most were not planetary scientists but other types of astronomers, and the fact that an equal number of planetary scientists signed a petition rejecting the IAU decision within three days. She also fails to mention that Brown did not discover Eris alone but as part of a team of three. Significantly, the other two members of Eris's discovery team, Chad Trujillo and David Rabinowitz, reject the IAU definition—another fact the article never states. Neither does it ever note that Pluto-Charon is actually a binary planet system.
Additionally, the writer states that Pluto does not “clear its orbit” because its orbit overlaps with that of Neptune. This was not the reasoning used by the IAU. As pointed out by Margo Schulter on Facebook's Society of Unapologetic Pluto Huggers (SUPH) page, the IAU’s issue was that Pluto orbits with many Kuiper Belt Objects, including some small planets, in the Kuiper Belt. Whether these count as being in Pluto’s “neighborhood” is questionable, as they are scattered in vast expanses of space nowhere near Pluto.
The writer states that debate over Pluto’s planet status began several decades after the planet’s discovery, which is wrong. The debate actually started almost immediately after its discovery because telescopes in 1930 could not resolve Pluto into a disk. Some scientists thought it was a moon of a larger planet, but such a planet was never found.
The article never mentions that Alan Stern is the person who initially coined the term "dwarf planet" and that he intended it to refer to a third class of planets in addition to terrestrials and jovians. The four percent of the IAU who voted on this misused his term. Nor does it acknowledge the post-New Horizons Pluto conference held a month ago.
And contrary to the writer’s claim, the IAU decision did not prompt "a wave of science textbook reprints." It did prompt some, but those are problematic because doing this represents an unquestioned acceptance of science by dictate of "authority." Journalists should be able to recognize the inherent problem in this. The better textbooks teach the controversy and present both sides of this ongoing debate. They also have companion websites they can update regularly.
This is better than many previous articles but still has a long way to go. There should be much more discussion of New Horizons' findings, its discovery of planetary processes seen elsewhere in the solar system only on Earth and Mars, and its likely subsurface ocean. Instead, we get what appear to be attempts at conversational language, with statements such as “how the mighty have fallen,” “Pluto planetary days are remembered fondly,” and “it's still arguably the coolest (non) planet to learn about -- literally speaking.” That phrase “non-planet” should not be there, even in parentheses, as it amounts to favoring one side.
To the writer’s credit, she does quote Alan Stern about Pluto’s complexity and mysteries, acknowledge Phil Metzger’s study on the history of planet definition, and report on last year’s public debate held at the Harvard-Smithsonian Center for Astrophysics, where participants voted overwhelmingly in Pluto’s favor.
Unfortunately, the article does not have a comments section, which is a decision by CNN but one that makes it impossible for people to respond and have an open conversation of their own.
At last month’s conference, Kirby Runyon addressed the issue of pedgagogy of the solar system. He emphasized that whether done through the schools or the media, teaching the solar system has to change based not only on discoveries in our solar system, but also on the 4,000 exoplanets discovered in the last 25 years. Instead of asking children to memorize a list of names, a 19th-century method, 21st century teachers need to focus on the large, whole solar system, complete with inner, middle, and outer zones. Runyon plans to reach out to educators and textbook publishers and encourage them to focus on a large, diverse solar system with many planets, including spherical moons of giant planets, some of which could have subsurface oceans capable of harboring life.
Change is happening slowly, but it is happening, and in the direction of moving away from the limited IAU view of eight planets to the reality of many in our solar system alone. We need to keep reaching out to the media, correct their errors, and inform reporters of facts they likely never previously heard.
Spread the word—planet Pluto lives!