Tuesday, December 12, 2017
Saturday, November 18, 2017
NASA's New Horizons mission to Pluto and the Kuiper Belt is looking for your ideas on what to informally name its next flyby destination, a billion miles (1.6 billion kilometers) past Pluto.
On New Year's Day 2019, the New Horizons spacecraft will fly past a small, frozen world in the Kuiper Belt, at the outer edge of our solar system. The target Kuiper Belt object (KBO) currently goes by the official designation "(486958) 2014 MU69." NASA and the New Horizons team are asking the public for help in giving "MU69" a nickname to use for this exploration target.
"New Horizons made history two years ago with the first close-up look at Pluto, and is now on course for the farthest planetary encounter in the history of spaceflight," said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate in Washington. "We're pleased to bring the public along on this exciting mission of discovery."
After the flyby, NASA and the New Horizons project plan to choose a formal name to submit to the International Astronomical Union, based in part on whether MU69 is found to be a single body, a binary pair, or perhaps a system of multiple objects. The chosen nickname will be used in the interim.
"New Horizons has always been about pure exploration, shedding light on new worlds like we've never seen before," said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.
"Our close encounter with MU69 adds another chapter to this mission's remarkable story. We're excited for the public to help us pick a nickname for our target that captures the excitement of the flyby and awe and inspiration of exploring this new and record-distant body in space."
The naming campaign is hosted by the SETI Institute of Mountain View, California, and led by Mark Showalter, an institute fellow and member of the New Horizons science team. The website includes names currently under consideration; site visitors can vote for their favorites or nominate names they think should be added to the ballot. "The campaign is open to everyone," Showalter said. "We are hoping that somebody out there proposes the perfect, inspiring name for MU69."
The campaign will close at 3 p.m. EST/noon PST on Dec. 1. NASA and the New Horizons team will review the top vote-getters and announce their selection in early January.
Telescopic observations of MU69, which is more than 4 billion miles (6.5 billion kilometers) from Earth, hint at the Kuiper Belt object being either a binary orbiting pair or a contact (stuck together) pair of nearly like-sized bodies – meaning the team might actually need two or more temporary tags for its target.
"Many Kuiper Belt Objects have had informal names at first, before a formal name was proposed. After the flyby, once we know a lot more about this intriguing world, we and NASA will work with the International Astronomical Union to assign a formal name to MU69," Showalter said. "Until then, we're excited to bring people into the mission and share in what will be an amazing flyby on New Year's Eve and New Year's Day, 2019!"
To submit your suggested names and to vote for your favorites, go to: http://frontierworlds.seti.org
Rebecca McDonald, SETI Institute
(650) 960 4526, firstname.lastname@example.org
Michael Buckley, Johns Hopkins Applied Physics Laboratory
(240) 228-7536, email@example.com
Laurie Cantillo, NASA Headquarters
(202) 358-1077, firstname.lastname@example.org
Saturday, September 30, 2017
Wednesday, September 27, 2017
Thursday, August 24, 2017
This year, the anniversary of the disastrous IAU planet definition vote that continues to cause confusion and misconceptions among the public has gone largely unnoticed—probably because three days ago, a total solar eclipse mesmerized thousands if not millions across the North American continent, and both pictures and accounts of that event are still being actively shared online.
The fact that so many people viewed the solar eclipse, whether in person or online, illustrates that the general public can, under the right circumstances, become excited about astronomy. Though not to the same extent, space missions such as Cassini at Saturn and Juno at Jupiter or the various rovers on Mars generate similar enthusiasm and attention if they are given appropriate media attention.
Two years ago, the New Horizons flyby generated the same kind of fascination with Pluto. People are naturally inspired by the solar system and exploration of its many worlds.
Astronomers, both amateur and professional, should be encouraging this kind of excitement, should want to share the wonders of the sky with the public.
In 2006, four percent of the IAU did the exact opposite. They decreed that they and only they can determine the identity of celestial objects, as if they somehow own these objects. Reaction to their decision was justifiably negative because that decision amounted to rejection of any cultural or popular conception of the solar system. Inherent in the message of the vote was the statement, the solar system is not yours. An object that looks and acts like a planet isn’t really a planet for some obscure reason no one really understands.
Keep things simple; keep the number of planets small. That was the real motivation behind the decision of August 24, 2006. And its message to the public was, when it comes to science, your views and understanding of the solar system mean nothing.
In his book Century’s End, author Hillel Schwartz discusses a controversy that has reared its head at the end of every century for 500-1,000 years. Does the new century start in the year 00 or 01?
There can actually be no correct answer to this question because the dating system we use is based on a mathematical error. It is a number line with numbers going from negative to positive but without the zero such a number line requires. The concept of the zero was unknown to the sixth-century monk who created the system.
Ordinarily, the first century would be the years 0-99, the second century the years 100-199, etc. But because the system has no zero, the first century, to have a total of 100 years, is actually the years 1-100, the second 101-200, etc. That is counterintuitive, as it tells us that the year 2000 is actually part of the old rather than the new century.
An interesting pattern developed over the last few hundred years. “Elites” such as scholars and intellectuals, advocated the counterintuitive method, the one viewed as requiring complex thinking rather than the popular conception. These people always insisted on centuries starting in the 01 year. In Boston, they refused to celebrate the beginning of the 20th century in 1900, then threw a grand public celebration in 1901.
In contrast, the general public went with the view that inherently sounded correct. They considered 1900 the beginning of the 20th century and 2000 the beginning of the 21st century.
The point here is a cultural one. The real issue at hand was the division between the “elites” and the common people. Anyone who wanted to sound educated or intellectual usually went with the counterintuitive 01 option, which supposedly showed they understood the complexity of the situation.
In reality, there can be no answer to this dilemma because the dating system is based on a mathematical error. Neither view is correct. This is why NASA, in its pages listing 5,000 years of solar and lunar eclipses, adds a zero to the count, assigning zero to the year 1 BCE, 1 to the year 2 BCE, etc. Predicting eclipses could not be done using an incorrect number line.
A similar phenomenon has happened regarding Pluto. Most members of the public grew up with Pluto being classed as a planet, and in the absence of a logical reason to change that, continue to consider it one. In contrast, those who want to seem intellectual or professional often adopt the other view, supposedly counterintuitive one. To them, “simple” people view Pluto as a planet while those who are more educated and intellectual understand the complexity of the issue and agree with the “experts” after understanding their line of thinking.
In other words, rejecting the “common” view supporting Pluto’s planethood has for some become a status symbol, a way of supposedly distinguishing themselves from the masses and showing they know more than the average person.
This is a psychological and cultural issue. It is not science, and it is bunk.
Eleven years after the vote on what the IAU has turned into a dogma they refuse to ever reconsider, the reality is many top planetary scientists in the world view Pluto as a planet. New Horizons sent back data showing Pluto to be a world that looks and acts like a planet. “Science” does not in any way support designating Pluto as anything else.
The August 21 solar eclipse showed the public enjoys engaging in astronomy and can be motivated to do so with appropriate outreach and education that brings people in rather than keeps them out.
In terms of media coverage and public attention, the eclipse also eclipsed the anniversary of the IAU vote.
One event involved embracing the public while the other centered on excluding them. We can only hope that renewed public engagement with astronomy continues to eclipse a bad decision by 424 non-experts 11 years ago.
Wednesday, August 16, 2017
This blog is mostly but not exclusively devoted to the issues of Pluto, dwarf planets, and planet definition. However, no planet or celestial body exists in isolation, and on various occasions, I have chosen to discuss other issues relating to planetary science and astronomy.
By now, most people are probably aware of the fact that a total solar eclipse will traverse the continental US on Monday, August 21. Locations outside the 70-mile path of totality, which crosses the country from northwest to southeast, as well as Canada, Central America, and the top of South America, will be treated to a partial solar eclipse.
Monday’s spectacle is a momentous occasion, a rare opportunity that should not be missed. While those who get to see the Sun completely covered by the Moon will hit the jackpot, the many more who will get to see a partial eclipse should not pass up the chance to do so—safely, of course, with eclipse glasses or indirectly using the pinhole projection method.
For anyone either clouded out or in other parts of the world, there will be numerous live online broadcasts in real time showing the stunning spectacle accompanied by educational commentary.
Unfortunately, some schools, both in and beyond the path of totality, are choosing to either do nothing for the eclipse or worse, keep students in rooms with drawn shades or no windows at all to prevent them from seeing it. Some are not even showing their students the online broadcasts.
These decisions rob children of a rare opportunity to see an unusual spectacle that can be watched safely. They reflect the way educational systems too often get things wrong, focusing on teaching to standardized tests rather than giving students an authentic learning experience.
In New Jersey, where I live, most schools don’t start until September, so this is not an issue. But in any state where schools are open, and bureaucrats make this indefensible choice, parents should either urge a policy change or keep their children home and watch the eclipse with them—even if that means watching online.
That’s right—Plutogirl is telling parents, even those not in the path of totality, in districts choosing to ignore the eclipse, to keep their kids home on August 21 and give them a better, firsthand educational experience than they would have received that day in school.
Such opportunities do not come around frequently. The US mainland has not seen a total solar eclipse since 1979. I would have loved to see one as a child, but there just weren’t any good ones during that time.
For people of all ages, this is a chance to take a break from disturbing national and world events and instead focus on the beauty of nature and a firsthand display of the motions of the Sun, Moon, and Earth. Seeing the results of these motions firsthand transforms our understanding of the solar system from abstract to experiential.
While I have personally seen several lunar eclipses, both total and partial, the only solar eclipse I’ve ever viewed personally was a very partial one in which, through telescopes made specifically for solar observing, one could see the Sun appear to have a small bite taken out of it.
I’ve known about this year’s total solar eclipse for at least ten years and probably longer. This one did not require traveling halfway around the world or to extreme climates. A decade ago, the first websites about this eclipse first went live online, emphasizing the goal of getting all Americans into the path of totality. I knew I wanted to go, and now it is actually happening.
Unfortunately, there are unscrupulous vendors who are selling counterfeit eclipse glasses that cannot be used to safely view the Sun. The American Astronomical Society has a list of reputable vendors of glasses and filters, which is posted at https://eclipse.aas.org/resources/solar-filters.
The website EarthSky has information on watching the eclipse safely, which everyone should read, at http://earthsky.org/tonight/how-to-watch-a-solar-eclipse-safely?utm_source=EarthSky+News&utm_campaign=8913d4e40d-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-8913d4e40d-393746501&mc_cid=8913d4e40d&mc_eid=a8cafeccf3.
Watch online through any of the live video streams listed at https://www.nasa.gov/eclipselive.
The Toshiba Vision screen in New York's Times Square will broadcast the program live in its entirety to give the public a big-screen view of the eclipse. Viewers in Times Square can listen to NASA coverage while observing it on the big screen by downloading the NASA app or going to https://www.nasa.gov/eclipselive.
SLOOH, a remote observatory with live feeds from telescopes around the world, will also broadcast the eclipse free online at https://www.slooh.com/shows/event-details/393.
Catch NASA’s live coverage using any of the following:
· NASA App for iOS -- http://itunes.apple.com/app/nasa-app/id334325516?mt=8
· NASA App for Android -- https://play.google.com/store/apps/details?id=gov.nasa
· NASA App for Amazon Fire and Fire TV -- http://amzn.com/B00ZVR87LQ
· The NASA App also is available to Apple TV users.
A list of additional smartphone eclipse apps can be found at https://www.space.com/37568-best-total-solar-eclipse-apps.html.
Happy and Safe Viewing!
Monday, May 29, 2017
Tuesday, March 28, 2017
Should Pluto be restored as a planet? - Nasa Tech Briefs :: NASA Tech Briefs
Please vote in the poll at the bottom of the article.
Please vote in the poll at the bottom of the article.
Monday, March 27, 2017
The Pluto/planet definition debate just took a turn toward the tenor of the 2016 US presidential election, with the most outrageous remarks coming from scientists.
It seems IAU Secretary General Piero Benvenuti and the scientist who discovered a planet but wants people to believe he “killed” one—Mike Brown—are tired of the debate and just want it to go away—or so they say.
Incredibly, Benvenuti thinks the debate has lasted this long solely due to Alan Stern! In a Canadian CBC News article dated March 24, 2017, he makes the following statement when asked why the debate has gone on for a decade after the 2006 IAU vote:
"Because of Alan Stern. Because of the Horizons team … Why am I not getting French schoolboys or Italian schoolboys or Iranian schoolboys writing to me about Pluto?"
There are so many things wrong with this statement that it’s hard to know where to begin addressing them!
Let’s start with the fact that the IAU describes its mission as “safeguarding the science of astronomy.”
Alan Stern spent 25 years tenaciously advocating an unmanned mission to Pluto. Because of his persistent dedication and effort, 7.5 billion people on Earth now have close up, high-resolution photos of Pluto. Because of the mission he fought for and put both brains and heart into for two-and-a-half decades, humanity has in-depth knowledge of the Pluto system, including its geology, its weather, its history, etc.
If not for the efforts of Alan Stern—along with those of the New Horizons team members—we would have nothing more than blurry pixelated images of this fascinating world.
One would think the head of an organization that bills itself as “safeguarding the science of astronomy” would give its highest commendations to a scientist who revealed a whole world and its system of satellites to the people of this planet.
Yet all Benvenuti can do is scapegoat and condemn Alan Stern—proof yet again that the IAU is more interested in safeguarding its self-appointed “authority” than the science of astronomy.
Galileo experienced a very similar reaction from the institution that saw itself as the “authority” of his day regarding astronomy.
Unfortunately for the IAU, the organization has no power to put Alan Stern under house arrest. Science by authority went out as of 1610.
Benvenuti does not even get the name of the Pluto mission right, erroneously referring to it as “Horizons” rather than New Horizons.
He claims French, Italian, and Iranian school boys—notice he did not even mention girls—are not sending him letters about Pluto. How do we even know this is true other than the fact that he says so? It’s quite easy to delete emails one does not want to read or send them to the spam filter. Benvenuti’s claim has no more to back it up than does Donald Trump’s claim that millions of illegal immigrants voted against him.
Even if schoolchildren of both genders aren’t writing to him, the reason is probably that they do not know who he is. People concerned about Pluto typically write to NASA, Neil de Grasse Tyson, and the American Museum of Natural History—the institutions or people they associate with either Pluto or astronomy in general. They are more likely to contact planetariums and observatories, especially those in their areas, than they are to write to the Secretary General of the IAU.
Benvenuti’s statement is a barely veiled claim that it is only Americans who care about Pluto’s status, and this is blatantly false. Support for Pluto’s planethood is not about American nationalism. It is about people looking at Pluto and seeing a planet.
If he thinks Alan Stern is the only reason the debate continues, he is sadly mistaken.
More than 300 planetary scientists signed the 2006 petition rejecting the IAU resolution. Numerous scientists have spoken and written against it over and over again for more than 10 years. And they have been joined by a large cohort of amateur astronomers, educators, writers, and members of the public around the world who continue to express their active opposition to the definition that states a dwarf planet is not a planet.
Even scientists not as vocal, such as Dr. Barrie Jones, author of Pluto: Sentinel of the Outer Solar System state they have no problem with the term “dwarf planet” but add that they reject the notion that dwarf planets are not planets at all. Many deliberately use the terms interchangeably as a quiet means of support for dwarf planets being a subclass of planets.
Here are just a few of the planetary scientists and science writers other than Stern who publicly and actively reject the IAU planet definition:
Gerard Van Belle
Carolyn Collins Petersen
George Musser, Jr.
Jason Schilling Kendall
This is just a short list, and I’m sure I will be adding more scientists and science writers to it.
There is also a huge movement online, sometimes humorously referred to as the “Pluto Resistance,” composed of thousands of people who have joined groups on Facebook and other social media opposing the IAU decision. Most also advocate planet status for the other dwarf planets, Ceres, Haumea, Makemake, and Eris. The largest such group is the Society of Unapologetic Pluto Huggers on Facebook.
Additionally, there are numerous websites such as plutoisaplanet.com, plutoisaplanet.org, plutoisaplanet.us, and many more, including this blog. These have stayed active for more than 10 years! Leading the “Pluto Resistance” for amateur astronomers and members of the public are Mike Wrathell, Raj Pillai, Bruce Reed, Carl Bergmanson, Michael and Nomi Burstein, P. Edward Murray, Janet Ivey-Duensing of Janet’s Planet, Steve Colyer, Andrew Brown, J. Richard Jacobs, Siobhan and Kevin Elias, Al Tombaugh, Annette Tombaugh-Sitze, Steven Raine, George Lewycky, Mark Andrew Holmes, Twila Gore Peck, Lawrence Klaes, Anthony Hallowell, Doug Turnbull, Scott Hedrick, Yael Dragwyla, Richard Hendricks, Gene Mikulka, John Bowman, Sr., and many more!
When Mike Brown says, “It's the same small group of people loudly complaining over and over the past decade” and claims the number of scientists who reject the IAU definition are “a vocal minority,” he is dead wrong.
His claim is the typical strategy of someone trying to discredit a movement by denying its popularity and attributing the position he opposes to only the outspoken people in the forefront. Like a typical politician, he simply repeats the same claim over and over again, with no proof whatsoever of its veracity.
Incredibly, Brown goes on to describe some of the pro-Pluto arguments as “insane!”
Of course, he does not say which arguments he deems insane. That would require him to give voice to those arguments and actually refute them. Ironically, he accuses the pro-Pluto side of being motivated by nostalgia and emotion when his tone makes it clear that his comments are driven by the emotion of frustration—frustration that he cannot get the world to accept his view of the solar system, even after more than a decade.
He, too, demonstrates ignorance regarding the New Horizons mission, stating, "If they can't make the case that the object that they sent their billion-dollar spacecraft to is interesting without having to co-opt the word planet, then they should have their spacecraft taken away from them. I mean, that's insane."
New Horizons’ total cost was $700 million, not billions of dollars.
Notably, JPL, where Brown is based, competed with APL in Maryland for a Pluto mission proposal in 2001. APL ultimately won the contest, which may be the source for the statement about taking the spacecraft away from the New Horizons team.
One thing supporters of the IAU definition have jumped on is the geophysical proposal’s inclusion of spherical moons as planets. The media has not helped, depicting the idea as far-fetched when that is hardly the case. Some of the top contenders for hosting microbial life in our solar system are spherical moons. These could someday be destinations for solar system colonization.
Even the evasive “Earth 2.0” could end up being the large moon of an even bigger exoplanet.
Spherical moons have been referred to as secondary or satellite planets for centuries. Their scientific classification as planets does not mean people cannot continue to refer to them as “moons.” It simply distinguishes those moons large enough to be rounded by their own gravity from the smaller, irregularly-shaped ones.
Brown exploits the issue of moons when, presuming to speak for everyone, he audaciously claims, “Nobody wants the Moon to be a planet” and laughs about it.
Since Brown personally and financially benefits from the Pluto debate by selling books and giving paid talks, one could question whether he really wants it to “go away.”
But contrary to his claim, Pluto is not just “one of many thousands of objects in the outer solar system.” It is one of a class of planets most numerous in our solar system and very different from those thousands of tiny KBOs.
Ironically, the world will get to know small planets, KBOs, and the outer solar system thanks to New Horizons’ extended mission.
If Benvenuti really wants the debate to “go away,” he should ask the IAU to rescind or suspend the 2006 resolution based on new data about Ceres and Pluto as well as the ever increasing number of strange exoplanets being discovered. Such a statement could simply acknowledge that it is far too early in our exploration of planets to come up with any specific definition, especially one so polarizing and exclusionary.
The IAU seems to want people to blindly follow its edicts. Maybe they need a reminder of Albert Einstein’s admonition, “Unthinking respect for authority is the greatest enemy of truth.”
We are not going away. The Pluto Resistance continues…
Sunday, March 26, 2017
Planet Again? Pluto, Most Moons Count Under Proposed Definition
Please vote in the poll about Pluto's status that is embedded in this article!
Please vote in the poll about Pluto's status that is embedded in this article!
Tuesday, March 14, 2017
The case for Pluto’s planethood is not at all grim--in spite of statements to that effect in articles published this month in the Australian-based publication Science Alert and in Forbes.com.
Both articles—the Forbes.com one by astrophysicist Ethan Siegel and the Science Alert one by writer Fiona MacDonald--are statements of interpretation rather than fact because they begin with a foregone conclusion that science somehow precludes Pluto—and dwarf planets in general—from being considered a subclass of planets.
This premise, written in wording that makes it appear to be factual rather than interpretive, is misleading and assumed to be true from the outset when this is hardly the case.
Consider the articles’ titles: Siegel writes “The Science Has Spoken: Pluto Will Never Be A Planet Again.” Using Siegel as an authority, MacDonald states, “An Astrophysicist Says Pluto Will Never Be A Planet Again, and We All Need to Move On.”
But science has not spoken. Ethan Siegal, one scientist whose field of study is not planets has spoken, and claimed to do so in the name of “science.”
And contrary to MacDonald’s claim, he hardly “penned a thorough takedown” of the argument for Pluto’s planethood.
Like most of the four percent of the IAU who voted for the controversial 2006 planet definition, Siegel is not a planetary scientist. His fields are galaxies and cosmology. This should not be at all understood as disrespectful to him. It just means he is not the go to person for determining what a planet is any more than Alan Stern is the go to person for defining the Big Bang.
In saying, “When it comes to planetary science, geophysics isn’t enough. In astronomy, the three rules of real estate also apply: location, location, location,” he self-identifies as a dynamicist. There is nothing wrong with that. What is wrong is his inherent assumption that his side of the planet definition debate is the only scientifically legitimate one, when this is not the case.
The same is true for MacDonald’s statement that “trying to make it (Pluto) a planet again could hurt scientific progress going forward.”
Legitimate debates between those holding conflicting perspectives—in this case, dynamicists versus geophysicists—do not hurt scientific progress. What does hurt such progress is blind acceptance of one self-appointed group as the only “authority” on an issue.
In a February 20 article about the proposal for a geophysical planet definition being presented at the Lunar and Planetary Sciences Conference, writer(s) identified as BEC Crew state, “Of course, nothing changes until the IAU makes a decision…”
Therein lies the real problem. Such a claim amounts to circular reasoning: A thing is true because the IAU says it is true, with no room for anyone, including those who actually study planets, to legitimately disagree.
For geophysicists, an object’s intrinsic properties, not its location, take precedence when it comes to definition.
Siegel’s primary objection to the proposed geophysical definition is that it would make over 100 objects in the solar system, including moons and asteroids, planets. This objection is based largely on the notion that our solar system cannot have “too many planets,” that having a large number somehow devalues the term “planet.”
An understanding of the geophysical definition makes it clear that an asteroid can never be a planet and vice versa. If an object in hydrostatic equilibrium is classed as an asteroid, that classification is wrong. If an object classed as a moon is in hydrostatic equililbrium, it is both a moon and a (satellite) planet. The two are not mutually exclusive, and it remains perfectly fine to refer to such objects as moons. Also classing them as planets simply distinguishes these moons from those not large enough to be in hydrostatic equilibrium, such as Mars’ moons Deimos and Phobos.
Objections to more than a limited number of planets go back several centuries. Galileo’s reference to the four largest moons of Jupiter, which he discovered, as planets, raised major objections beginning with the church, whose position was there could only be seven perfect planets—the seven known since ancient times, which include the Sun and Moon but not the Earth.
When William Herschel discovered Uranus in 1781, his first instinct was to consider his discovery a comet, again due to the strong societal belief that no planets could exist beyond Saturn.
Contrary to Siegel’s claims, one can be honest and reject the notion that “there are very clearly eight objects that are different from all the others” in our solar system, as this is far from the case.
Earth actually has much more in common with Pluto than it does with Jupiter. Both Earth and Pluto have solid surfaces and are geologically layered into core, mantle, and crust; both have large moons formed via giant impact; both have nitrogen in their atmospheres; both have floating glaciers; both have volcanism, and like Earth, Pluto may harbor an ocean (though a subsurface one). In contrast, Jupiter is composed largely of hydrogen and helium, much like the Sun, and has no known solid surface. It has its own “mini solar system” of rings and moons. Putting Earth and Jupiter in the same category while excluding Pluto makes no sense.
Ceres, Jupiter’s moon Europa, Saturn’s moons Enceladus and Titan, Neptune’s moon Triton, and Pluto have different dynamics in terms of what and where they orbit, yet they all are similar in being “ocean worlds” with heat sources that allow for subsurface liquid water that could potentially be home to microbial life. Should these similarities in their intrinsic properties be rejected because their locations are different?
In terms of location, Pluto may well revolutionize our notion of what a star’s habitable zone is. No one expected a world orbiting so far from its star to be capable of hosting life, yet with an underground ocean, Pluto may do just that.
Even a rogue planet that orbits no star is still a planet based on its intrinsic properties.
Siegel cites dynamicist Jean Luc Margot’s 2015 schematic to emphasize a dividing line between planets and non-planets based on orbit clearing. However, Margot’s graph is clearly based on a 2002 paper by Alan Stern and Harold Levison that acknowledged a distinction between objects that gravitationally dominate their orbits and those that do not but never used that distinction to determine the latter are not planets.
Take a look at Margot’s graph, and notice the similarity to the one by Stern and Levison below it:
With the exception of Eris, which had not yet been discovered when Stern and Levison’s paper was published, and the latter’s inclusion of Earth’s Moon, Margot’s dividing line is essentially the same as that of Stern and Levison, who designated objects above the line as “uber planets” and those below it as “unter planets” but never said the latter were not planets at all.
Scientifically, we can recognize this division without precluding those below the line from being considered planets. How? By recognizing that some planets gravitationally dominate their orbits while others do not. The former are called classical planets while the latter are called dwarf planets. Both, based on their intrinsic properties, fall under the broader umbrella of “planets.”
The IAU definition is insufficient in that it puts location over an object’s intrinsic properties. Maybe what we need is a planetary classification system that incorporates both intrinsic and extrinsic properties. Redesignating dwarf planets as a subclass of planets is an easy way to move in that direction. Some scientists have considered establishing a planetary classification system similar to the Herszprung Russell Diagram for stars or to the Star Trek system, that establishes multiple planet subcategories based on both an object’s intrinsic properties and location.
As for the hypothetical Planet X possibly lurking in the outer solar system, its discovery, mass, and orbital parameters do not change anything about Pluto or dwarf planets. Finding such a world would actually strengthen the position of those who recognize our solar system can and does have many planets.
Advocates of a geophysical planet definition do not need to “move on” or be patronized with statements telling them to do so.
All scientists—unless they just arrived from Vulcan—have biases and opinions. Good science is about acknowledging the difference between fact and interpretation, not imposing interpretation on the world and calling it fact. That is a disservice to everyone.
Thursday, March 9, 2017
Sunday, March 5, 2017
Friday, March 3, 2017
Tuesday, February 28, 2017
Thursday, February 23, 2017
In his Feb. 22 New Scientist comment, "Pluto is Still an Ex-Planet," Mike Brown attempts to impose one view in an ongoing debate as fact.
The community of planetary scientists who support Pluto's planet status is not, as he describes, "a small but vocal group" and is not limited to those on the New Horizons mission. Neither did a "majority of astronomers" reject the notion of Pluto retaining its planet status in 2006.
With these statements, Brown presumes a consensus in the science community that never existed. Planetary scientists and astronomers were just as divided about Pluto's status and about how to define the term "planet" 10 years ago as they are today.
Only four percent of the IAU voted on the controversial 2006 definition, and most were not planetary scientists but other types of astronomers. Their decision was immediately rejected by an equal number of professional planetary scientists in a formal petition released just days later.
Brown's claim that nothing about Pluto has changed since 2006 ignores the extensive findings of the New Horizons mission, all of which show Pluto to be a geologically living object with wind-blown dunes like those on Earth and Europa; flowing glaciers not seen anywhere else in the solar system besides Earth and Mars; tectonic forces; an internal heat source; cryovolcanoes, and even a possible subsurface ocean. All these are features characteristic of planets.
His citation of the discovery of Ceres as a precedent actually works against the argument he makes. Nineteenth-century telescopes were not powerful enough to resolve Ceres into a disk, so astronomers of the day had no way of knowing that unlike the asteroids discovered after it, Ceres is in hydrostatic equilibrium. As shown by NASA's Dawn mission, Ceres is very different from the majority of asteroids, which are largely rubble piles. Like Pluto, it experiences complex geological processes and may harbor an underground ocean.
It is misleading to conflate the new proposal's inclusion of Earth's Moon as a satellite planet with the geocentric view of the universe held 500 years ago. Compositionally, spherical moons are much like the terrestrial planets except for the fact that they orbit other planets instead of orbiting the Sun directly. Designating them as "moon planets," as the proposal does, sufficiently distinguishes them from planets in primary orbits around the Sun.
We can have a scientifically consistent definition of planet that includes numerous subcategories to account for both orbital dynamics and intrinsic properties.
Saturday, February 18, 2017
February 18, 1930, is a tribute to underdogs.
On this day, 87 years ago, 24-year-old Clyde Tombaugh, working at the Lowell Observatory with just a high school diploma, discovered planet Pluto using a blink comparator to move back and forth between two photographic plates of the same portion of the night sky, taken on January 23 and January 29 of that year.
Unfortunately, too often biased in favor of the controversial IAU decision, the mainstream media report that “Pluto was a planet for 76 years.” For many, ranging from top planetary scientists and astronomers to amateur astronomers to citizen scientists and members of the public, Pluto has been a planet—a known planet—for 87 years and counting.
Actually, Pluto has been a planet for four billion years and counting. It just took a long time for a late-coming species to the planet Earth to discover it.
Even ten-and-half years later, many people are unaware of basic facts about Pluto’s status—such as the fact that only four percent of the IAU voted on the definition that demoted Pluto, and most were not planetary scientists but other types of astronomers. In other words, they were NOT experts in this field and do NOT even study planets.
Just 333 of 424 IAU members present voted that dwarf planets should not be counted as planets, a misuse of the term “dwarf planet” as coined by Alan Stern, who intended the term to designate a third class of planets in addition to terrestrials and jovians.
Within several days, an equal number of professional astronomers and planetary scientists, about 300, signed a formal petition rejecting the IAU definition, a move that unfortunately got very little media attention.
For several years their petition and the names and affiliations of all signatories were posted online at http://www.ipetitions.com/petition/planetprotest/ . I am now reposting the wording of the petition as well as the names and affiliations of the signatories to keep this information available to the public.
“We, as planetary scientists and astronomers, do not agree with the IAU's
definition of a planet, nor will we use it. A better definition is needed.”
As noted on the original petition site, “In less than five days, the petition was signed by 300 professional planetary scientists and astronomers. The list of signatories includes researchers who have studied every kind of planet in the solar system, as well as asteroids, comets, the Kuiper Belt, and planet interactions with space environment. They have been involved in the robotic exploration of the solar system from some of the earliest missions to Cassini/Huygens, the missions to Mars, ongoing missions to the innermost and outermost reaches of our solar system, and are leading missions preparing to be launched. The list includes prominent experts in
the field of planet formation and evolution, planetary atmospheres, planetary surfaces and interiors, and includes international prize winning researchers.
“This petition gives substantial weight to argument that the IAU definition of planet does not meet fundamental scientific standards and should be set aside,” states petition organizer Dr. Mark Sykes, director of the Planetary Science Institute in Tucson, Arizona. “A more open process, involving a broader cross section of the community engaged in planetary studies of our own solar system and others should be undertaken.”
“I believe more planetary experts signed the petition than were involved in the vote on the IAU’s petition. From the number of signatories that the petition received in a few days, it’s clear that there is significant unhappiness among scientists with the IAU’s planet definition, and that it will not be universally adopted by scientists and text book writers. To achieve a good planet definition that achieves scientific consensus will require more work.” added co-sponsor Dr. Alan Stern, Executive Director of the Space Science and Engineering Division of the Southwest Research Institute.
PETITION PROTESTING THE IAU PLANET DEFINITION
FIRST NAME LAST NAME INSTITUTION
Hal Weaver Johns Hopkins University Applied Physics Laboratory
Ralph McNutt Johns Hopkins University Applied Physics Laboratory
Andrew Cheng JHU/APL
Amy Lovell Agnes Scott College
Darren Baird UCLA
Christopher Russell UCLA
Elizabeth Jensen UCLA
Mark Sykes PSI (Planetary Science Institute)
Michael Gaffey Space Studies, U. North Dakota
John Lambert The Boeing Company
Tony Farnham University of Maryland
David Rabinowitz Yale University *(co-discoverer of Eris)*
Curtis Cooper Lunar and Planetary Laboratory, University of Arizona
Alan Chamberlin Jet Propulsion Laboratory
H. Warren Moos Johns Hopkins University
Chris McKay NASA Ames
Eldar Noe Malin Space Science Systems
Scott Michael Indiana University
Jennifer Piatek University of Tennessee
Krista Soderlund UCLA
Sanjay Limaye University of Wisconsin
Kathy Rages SETI Institute
Erin Ryan University of Minnesota
Beatrice Mueller Planetary Science Institute
Barry Lutz Northern Arizona University
Stephen Maran American Astronomical Society
David Kuehn Pittsburg State University
Leslie Bleamaster Planetary Science Institute
Peter Bender Univ. of Colorado
Kenneth Mighell National Optical Astronomy Observatory
Larry Lebofsky U. of Arizona
Kem Cook Lawrence Livermore National Laboratory
David Levy Jarnac Observatory
Horton Newsom Univ. of New Mexico
Kurt Retherford Southwest Research Institute
Wendee Wallach-Levy Jarnac Observatory
Nanette Vigil Jarnac Observatory
Francis Graham Kent State University
janet luhmann SSL, Univ. of California, Berkeley
Bryan Butler National Radio Astronomy Observatory
Harold Geller George Mason University
Will Grundy Lowell Observatory
James Dire Gardner-Webb University
Nicola Richmond Planetary Science Institute
Peter Thomas Cornell University
Howard Smith University of Virginia
Alan Stern SwRI (Southwest Research Institute)
Vladimir Krasnopolsky CUA (Catholic University of America)
Colleen Milbury UCLA
Britney Schmidt UCLA
Jennifer Benson University Of Toledo
Alan Howard University of Virginia
Tae-Soo Pyo Subaru Telescope
Wayne Pryor Central Arizona College
Tanya Tavenner New Mexico State University
Steve Howell NOAO
Robert Carlson JPL
Jason Soderblom Cornell University
MARK WYSOCKI CORNELL UNIVERSITY
William Rossow City College of New York
William McKinnon Washington University
Jody Wilson Boston University
Iain Reid STScI (Space Telescope Science Institute)
Nadine Barlow Northern Arizona University
Mark B. Vincent MRO 2.4m, New Mexico Tech
Philip James Space Science Institute
Vishnu Reddy University of North Dakota
Denise Stephens Johns Hopkins University
Lawrence Wasserman Lowell Observatory
Colby Jurgenson Magdalena Ridge Observatory
Roger Knacke Penn State Erie
Darrell Strobel Johns Hopkins University
Steven Ostro JPL
Ronald Elsner NASA Marshall Space Flight Center
Robert Marcialis LPL (Lunar & Planetary Laboratory, Univ. of Arizona)
Mark Showalter SETI Institute
Linda Spilker JPL
Larry Paxton Johns Hopkins University
William Jackson University of California
Theodor Kostiuk NASA Goddard Space Flight Center
Robert Kolvoord James Madison University
Glenn Orton JPL
Paul Strycker New Mexico State University
Nicholas Sperling The University of Toledo
Mark Everett Planetary Science Institute
D. Chris Benner College of William and Mary
Jim Elliot Massachusetts Institute of Technology
Walter Huebner Southwest research Inst.
Michael Mickelson DENISON UNIVERSITY
Giles Marion Desert Research Institute
James Ferris Rensselaer Polytechnic Institute Institute
Henry Throop Southwest Research Institute, Boulder, CO
Larry Petro Space Telescope Science Institute
Chris Churchill New Mexico State University
Gordon Bjoraker NASA/GSFC
Robert Fritzius Shade Tree Physics
Daniel MacDonald JPL
Brendan Fisher JPL
Linda French Illinois Wesleyan University
Bernard Bates University of Puget Sound
Richard Tresch Fienberg Sky & Telescope
Mary Bourke Planetary Science Institute
Carol Neese Planetary Science Institute
Ed Smith STScI
Christopher Gelino Spitzer Science Center/IPAC
Richard Wagener Brookhaven National Laboratory
Truman Kohman Carnegie-Mellon University
John Stansberry Steward Obs., U. Arizona
Alex Storrs Towson Univ.
G. Leonard Tyler Stanford University
Brandon Lawton New Mexico State University
Mark Hammergren Adler Planetarium & Astronomy Museum
Peregrine McGehee Los Alamos National Laboratory
Robert Seaman National Optical Astronomy Observatory
Marc Buie Lowell Observatory
Landon Noll Fremont Peak Observatory
Adam Burgasser MIT
Michael Kelley Georgia Southern University
Uwe Fink Lunar and Planetary Laboratory, University of Arizona
David Crisp JPL/Caltech
H. Bradford Barber University of Arizona
Einstein Miller OCC, CU, MMCC
Robin Evans Gibbel Corporation
Kurt Anderson Apache Point Observatory and NM State University
Erik Asphaug University of California, Santa Cruz
William Newman UCLA
Jose Francisco Salgado Adler Planetarium
Stamatios Krimigis JHU/APL
Michael Mautner Virginia Commonwealth University
Simon Mitton University of Cambridge
Raul Baragiola University of Virginia
Michael Allison Goddard Inst for Space Studies
Cathy Olkin SwRI
Judith Young University of Massachusetts
Michael Kelley University of Minnesota
Meg Spohn University of Denver
Tashonia Blackwell Norfolk State University
Brian Warner Palmer Divide Observatory
Alison Bridger San Jose State University
Alanna Garay National Astronomical Observatory of Japan
Henry Alwyn Wootten Natl. Radio Astronomy Observatory
M. L. Delitsky CSE (College of St. Elizabeth)
Ira Nolt Retired NASA
Jayant Murthy IIA (Indian Institute of Astrophysics)
William Merline SwRI
Daryl Swade STScI
Amar Rao UCLA
Robert Novak Iona College
Joe Peterson Southwest Research Institute
Donald Jennings Goddard Space Flight Center
Michael Wolff Space Science Institute
Randy Gladstone SwRI
Jeffrey Moore NASA Ames Research Center
Fred Franklin Harvard-Smithsonian CFA
Kevin Stube University of Arizona
David Tholen University of Hawaii
Russ Walker MIRA (Monterey Institute for Research in Astronomy)
Eliot Young Southwest Research Institute
Michael Finch The University of Arizona
David Crown Planetary Science Institute
William Cassidy University of Pittsburgh
Joel Parker Southwest Research Institute
Noel Jackson University of Southern Queensland, Australia
David Portree Lowell Observatory
Jonathan Gradie BAE Systems NES Imaging & Surveillance
Philip Massey Lowell Observatory
Paul Grogger University of Colorado
Joseph Ajello JPL
Lou Weeks AAS Member
Galen Gisler University of Oslo
Thomas Stephens NASA GSFC
Jared Leisner UCLA
Gregory Hoppa Raytheon
Robert Barron Tel Aviv Uni.
Laurent Montesi Woods Hole Oceanographic Institution
Deidre Hunter Lowell Observatory
James Mueller JHU/APL
Michael Stevens Naval Research Laboratory
Scott Milster ATK Mission Research
Hoi Fung Chau University of Hong Kong
Knut Olsen National Optical Astronomy Observatory
Anthony Roman Space Telescope Science Institute
Catherine Johnson UCSD
Grace Wolf-Chase University of Chicago
Bernard Noeller Community College of Baltimore County
Ellen Howell Arecibo Observatory
Robert Reynolds University Of Arizona - LPL
Thomas Kehoe University of Florida
David Hinson Stanford University
Dan Moynihan Lunar and Planetary Laboratory
Glenn Dantzler Settlemyre Planetarium
Thomas Hill Rice University
Justin Bartel Kansas Cosmosphere and Space Center
Rodney Martin Wm. Brish Planetarium
Steven Russo Schenectady Museum Planetarium
Maurice Collins Amateur Astronomer
Douglas ReVelle Los Alamos National Laboratory
John Cooper NASA Goddard Space Flight Center
Martha Leake Valdosta State University
JOHN BRANDT U. of New Mexico
Duncan Young University of Texas
Chuck See University of Arizona
Stephen Becker Los Alamos National Lab
Bonnie Buratti Jet Propulsion Laboratory
Sally Oey University of Michigan
Laurence Trafton Univ. Texas at Austin
David Bartlett University of Colorado
Faith Vilas MMT Observatory
David Grinspoon Denver Museum of Nature & Science
Carolyn Shoemaker USGS
Robert Craddock Smithsonian Institution
Priscilla Cerroni IASF INAF Roma Italy
John Dragon Los Alamos National Laboratory
Charles Cowley Astron. Dept. U. of Michigan
Wayne Hayes University of California, Irvine
Nilton Renno University of Michigan
Amy Simon-Miller NASA Goddard Space Flight Center
Louise Prockter JHU/APL
David Klassen Rowan Univeristy
Bradley Schaefer Louisiana State University
Ilana Dashevsky STScI
Lawrrence Sromovsky University of Wisconsin - Madison
Richard Schmude, Jr. Gordon College
David Weintraub Vanderbilt University
Barbara Carlson NASA/GISS
Gary Copeland Old Dominion Univsersity
Gerhard Neukum Freie Universitaet Berlin, Germany
Yi-Jehng Kuan National Taiwan Normal University
Tom Van Flandern Meta Research
Edward Tedesco University of New Hampshire
John Richardson M.I.T.
Jon Jenkins SETI Institute
Dariusz Lis California Institute of Technology
Minho Choi Korea Astronomy and Space Science Institute
David Dunham Johns Hopkins Univ./Applied Physics Lab.
Michael Haken NASA/GSFC
Craig Fry Exploration Physics International, Inc.
Jean Chiar SETI Institute/NASA Ames
Clark Chapman Southwest Research Inst.
Jasmine Santana University of Michigan, Ann Arbor
Laura Woodney California State Univ, San Bernardino
Fran Bagenal University of Colorado
Gregory Smith SRI International
Victoria Meadows IPAC/Caltech
Shane Byrne University of Arizona
Steven Lee Denver Museum of Nature & Science
Susan Postawko University of Oklahoma
Michael Summers George Mason University
Amy Donnelly Herkimer BOCES Planetarium
Joseph VEVERKA Cornell
Herbert Beebe New Mexico State Univ (retired)
Niescja Turner Florida Institute of Technology
Bidushi Bhattacharya Spitzer Science Center, Caltech
Paul Helfenstein Cornell University
David H. Smith National Research Council
Howard Houben Bay Area Environmental Research Institute
Carrie Anderson New Mexico State University
Bernhard Schulz IPAC/Caltech
Scott Severson UCO/Lick Observatory
Carl Grillmair Spitzer Science Center
James Colbert Spitzer Science Center
Thomas Jarrett IPAC/Caltech
Reta Beebe New Mexico State University
Oliver Hartmnann FU Berlin, Remote sensing of the earth and planets,
Melissa Nelson University of New Mexico
Patrick Ogle Spitzer Science Center
Larry Friesen University of Houston at Clear Lake
Jeffrey Bary University of Virginia
Roc Cutri IPAC/Caltech
John McGraw University of New Mexico
Paul Steffes Georgia Institute of Technology
Paul Romani NASA - Goddard Space Flight Center
W. David Carrier, III Lunar Geotechnical Institute
Stephen Shawl University of Kansas
Regina Cody NASA Goddard Space Flight Center
Thomas Kelsall NASA/GSFC (ret.)
Stephen Baloga Proxemy Research
Todd Clancy Space Science Institute
Dennis Matson JPL
Nicole Rappaport JPL
Barbara Anthony-Twarog Univ. of Kansas
Bruce Twarog University of Kansas
Bob Molloy Spitzer Science Center/Caltech
Steve Bryson NASA Ames
Gilbert Esquerdo Planetary Science Institute
Paul Abell Planetary Science Institute
David Osip Observatories of the Carnegie Institution of Washington
Kandis-Lea Jessup Southwest Research Institute
David Huestis SRI International
Ray Russell The Aersospace Corporation
Don Davis Planetary Science Institute
Jim Thieman NASA/GSFC
Samuel Dupree Lockheed Martin Integrated Systems and Solutions
Amara Graps INAF-Istituto di Fisica dello Spazio Interplanetario (IFSI)
Sze-leung Cheung Ho Koon Astronomical Center Hong Kong
Stefan Schroeder Max-Planck-Institut fuer Sonnensystemforschung
Pablo Gutierrez-Marques MPS (Max Plancke Institute for Solar System Research)
Michael DiSanti NASA-Goddard Space Flight Center
Sebastian Walter FU (The Freie Universität), Berlin
Andrew Potter National Solar Observatory
Irwin Shapiro Harvard-Smithsonian Center for Astrophysics
Feng Tian NPP (NASA Postdoctoral Program)
Douglas Caldwell SETI Institute
Patricio Rojo Universidad de Chile, Astronomy Department
For those who have not seen it, here are links to my February 18, 2013, blog entry, “Responding to the IAU: Pluto and the Developing Landscape of Our Solar System.” This is a point-by-point rebuttal of the IAU’s statement justifying the 2006 vote, posted on its home page (Content is identical on both sites): http://laurele.livejournal.com/2013/02/18/ and http://laurelsplutoblog.blogspot.com/2013/02/responding-to-iau-pluto-and-developing.html