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Queen guitarist Brian May weighs in on Pluto as a planet [Sep. 1st, 2019|07:47 pm]
Support for Pluto's planet status is growing! First NASA Administrator Jim Bridenstine, now astrophysicist and Queen guitarist Brian May join the Pluto-is-a-planet team, which already has the support of numerous planetary scientists as well as that of former NASA engineer Homer Hickam and the Star Trek's original Captain Kirk, William Shatner.

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Reprinted from SpaceFlight Insider

Pluto 2

A comment by NASA Administrator Jim Bridenstine affirming he still considers Pluto to be a planet has drawn criticism from some media outlets that may be motivated more by politics than science. It is also a potential game changer in the decades-long planet debate.

On Friday, August 23, Bridenstine publicly stated his support for Pluto’s planet status while taking a tour of the University of Colorado at Boulder‘s Aerospace Engineering Sciences Building. A video of Bridenstine’s statement was posted on Twitter by Cory Rappenhagen, a meteorologist at Colorado’s 9News TV station.

“Just so you know, in my view, Pluto is a planet. You can write that the NASA Administrator declared Pluto a planet once again. I’m sticking by that; it’s the way I learned it, and I’m committed to it,” Bridenstine said.

Thirteen years ago, the International Astronomical Union (IAU) adopted a planet definition that excluded Pluto. The definition required planets orbit the Sun, be large enough to be rounded by their own gravity, and clear the neighborhood of their orbits.  Pluto does not meet the last condition because it orbits in the Kuiper Belt, a region of tiny icy bodies and was therefore labeled a dwarf planet.

The move was prompted by the recent discovery of several small objects in the Kuiper Belt, especially Eris, which is slightly smaller though more massive than Pluto.  Rather than class them all as planets, the IAU chose to place them in this separate category under the justification that the solar system cannot have too many planets because children will not be able to memorize all their names.

However, scientists who oppose the definition noted memorization is an archaic method of teaching the solar system and pointed out there is no scientific basis to the argument that the solar system cannot have too many planets.

The definition was controversial for many reasons, including the fact that it was enacted by just four percent of the IAU‘s membership, with many planetary scientists signing a petition rejecting.

Alan Stern of the University of Colorado at Boulder, principal investigator of NASA’s New Horizons mission to Pluto and longtime opponent of the IAU definition, emphasized no solar system planet fully clears its orbit of asteroids and comets. Jupiter orbits with a host of Trojan asteroids, and even Earth has asteroids in its orbital path.

Also problematic is the fact that the IAU definition gives primacy to an object’s location over its intrinsic properties. Some scientists noted that if Earth were in Pluto’s orbit, it would not clear that orbit of Kuiper Belt Objects. This means the IAU definition could result in the same object being labeled a planet in one location and not a planet in another location. It is also biased against objects in more distant orbits, which have larger orbits to “clear.”

And in spite of the discovery of numerous exoplanets orbiting stars other than the Sun, the IAU definition requires a planet to orbit the Sun rather than a star.

Ironically, the term “dwarf planet” was first coined by Stern in a 1991 paper as the proposed name for a class of small planets large enough to be rounded by their own gravity but not large enough to gravitationally dominate their orbits. In a 2000 paper, Stern and Hal Levison of the Southwest Research Institute in Boulder (SwRI) distinguished between planets that gravitationally dominate their orbits, which they called “uber planets,” and those that do not, which they called “unter planets.”

However, they never proposed that “unter planets” or dwarf planets not be considered planets at all, which runs counter to the use of the term “dwarf” in astronomy, as dwarf stars are still considered stars, and dwarf galaxies are still considered galaxies.

These papers became the basis of the geophysical planet definition crafted by Stern and favored by many planetary scientists. The geophysical definition rejects the notion of orbit clearing, instead requiring an object to orbit a star, not be a star itself, and be large enough to be rounded by its own gravity to attain planet status. Bridenstine’s declaration puts him firmly on the side of those advocating the geophysical definition,

In 2015, NASA’s New Horizons spacecraft flew by Pluto and found it to be far different from the dead rock many expected. Active geologically and possibly host to a subsurface ocean, Pluto has a layered atmosphere, varied terrains, interaction between its surface and atmosphere, and cryovolcanoes. Some processes seen on Pluto have been found elsewhere in the solar system only on Earth and Mars. Yet the spacecraft’s findings did not prompt the IAU to revisit the issue.

Bridenstine’s public rejection of the IAU definition generated controversy. On Tuesday, August 27, Business Insider‘s Tom Porter  questioned Bridenstine’s qualifications for the job of NASA Administrator in an article titled, “Trump’s NASA chief, who has no scientific background, says Pluto is a planet.”

Bridenstine was criticized after his nomination for the NASA administrator position in 2018 because he is not a professional scientist and was not chosen from within NASA ranks.  Some critics painted him as a climate change denier though Bridenstine has since publicly declared his acceptance of the fact that climate change is driven by human activity.

A former Congressman from Oklahoma, Bridenstine served as a Navy pilot and and previously ran the Air and Space Museum in Tulsa, Oklahoma. He is the primary mover of NASA’s Artemis program, which aims to return humans to the Moon in 2024. In contrast to the Apollo program, Artemis is the first step toward a long-term human presence on the Moon.

According to planetary scientist Will Grundy of the Lowell Observatory, who serves as a New Horizons co-investigator, Bridenstine’s view is very much in line with that of many planetary scientists.

“He’s just using the word the way planetary scientists use it, nothing unusual there,” Grundy said regarding Bridenstine.  “Sure, there was that controversial IAU vote back in 2006, but it’s important to realize that’s not how planetary scientists use the word, and there’s no reason for the public to use it that way, either.  Planetary scientists are interested in planets’ diverse compositions, structures, and the processes that operate on them.  Those things don’t go away or become uninteresting for a planet that’s in the wrong orbit according to the IAU definition.”

Porter’s article made no mention of the fact that Pluto’s status remains a matter of debate in the science community. A list of articles he recently wrote for Business Insider reveals he is a frequent critic of US President Donald Trump, raising the question of whether his article might be motivated more by politics than by science.

Britain’s Mirror chided Bridenstine for calling Pluto a planet 13 years after it was “declassified,” also without any acknowledgment of the ongoing debate among scientists.

Planetary scientist Phil Metzger of the University of Central Florida (UCF), who earlier this year published an article on the history of planetary taxonomy in the journal Earth and Planetary Astrophysics, commended Bridenstine for taking a stand in favor of the geophysical definition.

“I think Jim Bridenstine knows that the public’s thoughts about Pluto aren’t just sentimentality. People understand that a planet is a special thing in nature, the just-right type of place between cold lifeless asteroids and hot lifeless stars. Planets are where complex geology and possibly even life can exist. This is deeply important to science and deeply important to who we are as human beings. People look at Pluto and they see this flourishing of emergent complexity which makes planets important — more in Pluto than in any other planet besides Earth. I think Jim has tapped into the public’s instinct about this.”

While the IAU has shown no interest in revisiting the issue, the debate has continued for more than a decade. In 2017, planetary scientist Kirby Runyon of the Johns Hopkins University Applied Physics Laboratory (JHUAPL) presented the geophysical planet definition first proposed by Stern at that year’s Lunar and Planetary Sciences Conference as an alternative to the IAU definition.

At the heart of the planet debate is the question of who decides what a planet is and whose definition is deemed “official.” While much of the mainstream media has granted official status to the IAU, Stern and other scientists reject this along with the notion that science can be done by voting rather than through an organic process.

“The NASA Administrator is right in his views,” Runyon emphasized. “Professional planetary scientists also refer to Pluto and the 120+ similarly sized (solar system) planets as full planets.”
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Thirteen Years Later, Pluto is Still A Planet [Aug. 24th, 2019|10:33 pm]
Pluto's Heart

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!

Pluto Lives
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Life's Prospects on Pluto: September 2019 Issue of Astronomy Magazine [Aug. 14th, 2019|03:52 pm]
Sputnik Planitia 3

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Alan Stern - Pluto: Planet Or Not? [Jul. 21st, 2019|11:48 pm]
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Historic Apollo 11 Moonwalk Footage [Jul. 20th, 2019|11:34 pm]
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Celebrating #Apollo50 [Jul. 20th, 2019|03:05 pm]

There is a lot of new information to report about Pluto, especially from a conference titled “Pluto System After New Horizons” held last week at the Johns Hopkins University Applied Physics Laboratory (JHUAPL) in Laurel, Maryland, part of which I attended.

But because this blog is not just about Pluto but also about the solar system and planetary science, today I feel compelled to write a post honoring the 50th anniversary of the July 20, 1969, Apollo 11 Moon landing, an accomplishment that can legitimately be considered the most important event in the history of the world and the pinnacle of human achievement.

In June, I received an invitation from Steven Silver to write an article about the personal and cultural impact of the first Moon landing, to be published in a special edition of the Hugo Award-winning fanzine Journey Planet edited by Silver along with James Bacon and Christopher J. Garcia, to be published today.

Because I personally cannot remember anything about the momentous accomplishment that occurred 50 years ago today, I was unsure of what to write and ended up missing the deadline.

The only memory I have of crewed Moon missions is a very vague recollection of the launch of Apollo 17 in December 1972.

Observing the national and even global online celebrations of this event have helped me realize one does not have to actually have been present to recognize the enormity of this day and milestone because this event is bigger than any individual or even country.

And it was followed by a series of exploration projects, both crewed and un-crewed, that transformed the planets of our solar system from remote concepts to real, physical locations we could see and study.

Too often, especially in the news today, we read about and see the worst of humanity—greed, hate, cruelty, corruption, and denial in the face of impending climate disaster. Apollo 11 and subsequent space exploration, much of which required international cooperation, show us the opposite—how much humans can accomplish for good when we come together and work toward a goal.

Anne Frank, who would have been 40 in 1969 and 90 today, famously wrote in her diary, “In spite of everything, I still believe that people are really good at heart. I simply can’t build up my hopes on a foundation consisting of confusion, misery, and death. I see the world gradually being turned into a wilderness; I hear the ever approaching thunder, which will destroy us too; I can feel the sufferings of millions and yet, if I look up into the heavens, I think that it will all come right, that this cruelty too will end, and that peace and tranquility will return again.”

A plaque left by the Apollo astronauts on the Moon, on the site known as Tranquility Base, famously reads, “Here men from the planet Earth first set foot upon the Moon July 1969, A.D. We came in peace for all mankind.”

The stuff of dreams, the first Moon landing and all subsequent space exploration shine as beacons of hope, not just for the United States, but for all humanity. They confirm that we, all humanity, can come together for good, and that when we do, we can accomplish great things.

I believe that ending the Moon missions, especially when Apollos 18, 19, and 20 were completed for launch, was a mistake. This is likely due to the fact that our Moon missions were motivated more by the desire to win the space race against the former Soviet Union than by the quest for knowledge and exploration. Ultimately, our voyages to the final frontier must be motivated by the compulsion to explore, not by war. When we return humans to the Moon, it needs to be to stay rather than for one moment of victory.

Anne Frank did not live to see it, but the peace and tranquility she saw when looking upward did not just return but reigned supreme on that momentous day in human history 50 years ago. We can best honor Apollo 11 by coming together as one people on one planet, and using our ingenuity, bring emissions and climate change under control and forge a new era of exploration that will ultimately take us to the solar system and the stars.
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Experience Wonder: 125 Years of Lowell Observatory [Jun. 4th, 2019|11:57 pm]
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Support Planetary Blocks: Our Solar System Project--Pluto is Included! [Jun. 4th, 2019|08:07 pm]
The Planetary Society and Chopshop Store and Studio are seeking support for their Kickstarter project featuring a set of 20 Planetary Blocks. These wooden blocks each have six sides with beautiful images and information about various solar system worlds—the Sun, the four terrestrial planets, the four gas giant planets, the four dwarf planes, and eight spherical planetary moons.

Information on each block will include the object’s appearance, relative size, orbital distance, name, composition, and images of the robotic spacecraft sent to explore them. A portion of the sales of these blocks will go toward the Planetary Society.

The Sun, 11 planets, and 8 moons are obviously just some of the solar system’s worlds; these particular ones were chosen because we have the best images and data about them. As more of the solar system is explored, more worlds will likely be added to both the list of those visited and maybe even to those depicted in this project or others like it.

Yes, Pluto is included with the 11 planets! And the eight spherical moons, being rounded by their own gravity, all qualify as planets under the geophysical planet definition—as do more spherical moons that will hopefully be depicted on future blocks. Several ocean worlds in addition to Pluto, such as Jupiter’s moon Europa, are part of this set. These exciting worlds could yet be the first places where we someday find life beyond Earth.

While these blocks are toys, they are not just for kids! They make a terrific gift for all fans of space, planetary science, and the solar system.

Also included with the blocks is a giant fold-out supplemental chart loaded with extra facts and data and expands on the scale and distance sides of the blocks.

This notice comes late, as there is just one day left in the Kickstarter program. The project’s fundraising goal has already been met, but I encourage everyone who can to contribute to the Kickstarter. A variety of rewards come with different contribution levels.

Even when the fundraiser ends tomorrow, June 5, at 11:15 pm EDT, you can still support the project by purchasing these beautiful blocks for anyone who might appreciate them, including yourself!

Our solar system is a wonderful place filled with planets. Learn more about our Sun and some of these planets by supporting this project and by purchasing these planetary blocks. Visit the Kickstarter site at Planetary Blocks: Our Solar System.

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