Pluto Celestial Outsider? By Anton Komarov-Consultation and Interview with Laurel Kornfeld.
TNO's
Pluto
Galileo
William Hershell
Urban le Verrier
Percival Lowell
Clyde Tombaugh
Gerard Kuiper
Kenneth Edgeworth
Alan Stern
Mike Brown
New Horizons
Charon
Eris
Sedna
Scattered Disk
Planet X
Pluto
Pluto Celestial Outsider? By Anton Komarov
Consultation and Interview with Laurel Kornfeld.
06/10/2021
Anyone interested in space exploration, having planetary science as a profession or simply an amateur in astronomy has heard about the debate, is Pluto a fully fledged planet? The debate is intense between the partisans of Pluto as a planet as against the partisans of the IAU decision to declassify Pluto with both sides accusing each other of having obsolete and non scientific arguments. An impassionate observer would find it difficult to decide between both positions and to make things worse, it is a story where all the protagonists are intensely passionate in their subject/field of study, a passion which goes well beyond professional interest. This article has no pretention to give a clear cut answer but more of a guideline for the lambda reader and we hope it will allow everyone to reach an opinion on their own. To help us achieve this, we will analyse what the two main actors in this intellectual conflict have to say. Dr.Mike Brown and Dr.Alan Stern[1] are the front runners in this cosmic clash. Mike Brown[2] is well known in the community for his work on dwarf planets, the denizens of the Kuiper belt.
Mysterious objects, most of whom are lurking well beyond the orbit of Pluto and his discovery of Eris, a world aptly named after the Goddess of strife and discord as it would challenge the status of Pluto being a Planet. Alan Stern and his team offered the world the very first encounter of mankind with Pluto, a small world and its complex system of moons when the space probe New Horizons flew by Pluto in 2015 after nine years of solitary odyssey in the vastness of the Solar System. They had been the conceivers and caring parents of the mission. Our consultant for this article is Laurel Kornfeld; she will guide us through our quest for understanding of the subject. Laurel’s handle on Twitter is @plutosavior which tells you straight forwardly on which side of the fence she stands. Her blog is fill with a plethora of details as to why Pluto should return to the planetary arena of the Solar system. One could not refrain from comparing @plutosavior with @plutokiller which is the code name of Mike Brown on Twitter. Originality and passion are not only what characterises the fight of Laurel Kornfeld, if her battle horse is to reinstate Pluto, the weaponry she uses to do so are the ones planetary science provides, she has completed a Graduate Certificate of Science in Astronomy at Swinburne University. A fellow activist, she holds a BA in Journalism from Rutgers University and an MA in Middle East studies.
[1] Alan Stern [2] Mike Brown
Triumph
of Newtonian Gravity
But the Story does not start with the controversial decision of the International Astronomical Union on August 24th, 2006 to relegate Pluto to the less glamorous denomination of Dwarf Planet.[3] Actually the story started exactly 200 years ago in 1821. The Planet Uranus was the first one to be identified since antiquity and was not behaving according to the calculations of the astronomers and the only reason which could explain the irregularities in path of Uranus was an unknown mass disturbing the giant’s path around the sun. A generation later in 1841 in a triumph of Newtonian gravitational theory, the French Astronomer Urbain Le Verrier discovered Neptune. It was a very close run as an English man; John Couch Adams independently arrived at the same conclusion around the same time.
Worse still, pre-discovery evidence exists that Neptune was spotted by Joseph Jérôme Lefrançois de Lalande in 1795 and John Hershell, the son of William Hershell, the discoverer of Uranus in 1830. Unfortunately, none of the men of science recognised the object as a planet. More troubling, earlier in time, the Renaissance man Galileo drew Neptune on December 28th, 1612 and again on January 27th, 1613. Originally, it was thought that the prolific Galileo[4] did not recognize Neptune as a planet. Some better equipped astronomers also confused the Ice giant with a star preceding the discovery of the planet but in 2009, physicist David Jamieson of the University of Melbourne announced new evidence showing that Galileo had found something suspicious about this particular star.
[3]IAU Announcement [4] Galileo - Neptune
A New Hunt
Why is this historical reminder important? Because Neptune had been discovered by the tip of a pen and if the quote is not exact, it is in those approximate terms that François Arago, the famous French mathematician and Physicist of the time who qualified the discovery stated and he was right. When using Newtonian gravitational mechanics, Urban le Verrier predicted the position of Neptune to less than 1 degree from the position it was observed by the Astronomer Johann Gottfried Galle on the 24th of December 1846. The human dimension of the story caused a lot of noise about who was the real discoverer and would only find its conclusion when in 1999, lost (because they had been stolen)[6] papers were found in Chile. This lead to determining that Adam's position was exaggerated and his positioning of Neptune had vacillated up to 20 degrees arc. But those human considerations were meek compared to the cosmic bomb that the discovery announced. If Neptune was the first Planet X to be tracked successfully, very quickly it seemed evident that here too, it was erratic in her orbit and this perturbation could only be explained by another unidentified planet that was lurking behind and therefore, there was place for another man to inscribe his name in the history of Astronomy.
[6] Neptune's Secret.
Neptune & Uranus [Ice Giants]
Urban Legend
This new Planet X was more problematic to hunt for and it took 84 years, just 16 years short of a century to find it. In 1930, the news went around the world that Clyde Tombaugh from the Lowell Observatory had finally discovered the elusive Planet X, later baptized Pluto. That is the story that the layman having been educated and having little interest in things of the cosmos knows and he would probably know the anecdote of the little English school girl, Venetia Burney who was an eleven-year-old schoolgirl in Oxford, England naming the planet. Some will even tell you that she was fond of the Disney cartoon character Pluto and so decided to propose the name to the observatory which had the right as discoverers, to baptize the object. It is a very nice story but the history of Astronomy has its urban legends and that is one of those which has stubbornly appeared every now and then since the 1930’s. The truth lies in what happened in between the discovery of Neptune and the discovery of Pluto. Flash back to 1848 when the French physicist, mathematician and astronomer Jacques Babinet, calculated that to explain the irregularities in Neptune’s orbit, the hypothetical planet X should be 12 times the earth’s mass. Since then until more modern times, the mass of Pluto would be wrongly estimated continuously[7]. Enter the colourful character of Percival Lowell[8], a gentleman who grew a passion for Astronomy and put his wealth to the dedication of this science. From 1930, the Lowell Observatory was known and celebrated for the discovery of Pluto and the work of its founder in finding the last planet of the solar system but before this time, it was largely ostracised by the Astronomical community for a few reasons, the main one being the ideas of Lowell about a civilisation existing on Mars. Percival Lowell’s love for Astronomy was inflamed by a translation mistake. During the great Martian opposition of 1877, Italian Astronomer Giovanni Schiaparelli observed a network of straight lines on Mars that he described as Canali, since the word canalein in Italian could mean a gully, a canal, a channel or a duct. It was incorrectly translated into English as canals.
Furthermore, these networks of long straight lines in the equatorial regions from latitude 60° north to 60° south on Mars were observed and drawn by many astronomers of the time and were later revealed to be an optical illusion due to the low resolution of the optical instrumentation used during this period of time. However at this time, a few astronomers thought that it was proof of a neighbouring extraterrestrial civilisation and Percival Lowell was one of those. So convinced was he that he wrote three books on the subject, Mars (1895), Mars and Its Canals (1906), and Mars as the Abode of Life (1908) and remained until the end of his life on November 12th, 1916, committed to the idea despite the fact that the majority of Astronomers did not adhere to the proposition. It must be noted that Percival Lowell’s Ideas were very popular among the general public. One of the most gifted observers of the time, Edward Emerson Barnard known for his work on the high proper motion of Barnard Star, our famous neighbouring star which is named after him, did not see the famous canals. Then others in 1903 like Joseph Edward Evans and Edward Maunder mounted experiments proving that it was an optical illusion but not even the high quality pictures obtained from the Pic du Midi observatory in 1909, would convince him to the contrary. We will not judge the wealthy businessman astronomer on one eccentricity but Percival Lowell had others, he claimed to have observed surface features on Venus, the closest neighbouring planet. Astronomers of the time already suspected that this feat was impossible due to the impenetrable thickness of the atmosphere to the naked eye. However here again Lowell, may have been victim of the calibration of his instrument to allow daytime observation, a counter effect he did not foresee. However Lowell’s assumptions were very popular among the public and the wealthy gentleman had scored genuine achievements in the name of Astronomical Science. Wikipedia writes …his practice of building observatories at the position where they would best function has been adopted as a principle. He also established the program and setting which made the discovery of Pluto by Clyde Tombaugh possible. Lowell has been described by other planetary scientists as "the most influential populariser of planetary science in America before Carl Sagan". He was a Fellow of the American Academy of Arts and Sciences in 1892 and recipient in 1904 of the Prix Jules Janssen, the highest award of the prestigious Société Astronomique de France, the French Astronomical Society. As a matter of a fact, Percival Lowell for his constant use and implementation of new technology like Elon Musk today made it clear that there was method in his madness. Thus from 1894 to 1916, Lowell assembled and managed a task force consisting of human computers like the famous Elizabeth Langdon Williams (who could be described as the Information technology Guru Alan Turing put it as ‘someone who is supposed to be following fixed rules; he has no authority to deviate from them in any detail.) to calculate the position of the mysterious planet X. From 1914, the instrumentation used was capable of capturing a faint object like Pluto. From the three quoted observation ventures of Percival Lowell, the obsession for tracking Planet X is the one most related to hard science and the technique had earlier proved its worth spectacularly with the discovery of Neptune. By 1909, along with William H.Pickering, he had proposed a few possible coordinates for Planet X. At the age of 61, he died of a cerebral haemorrhage at Mars Hill and never knew how close he was to finding Pluto. Another human factor came in to play and certainly delayed the final triumph fourteen years after the death of Lowell. The wealthy businessman astronomer left half a million dollars as a legacy to fund the quest for planet X but his widow Constance Savage Keith whom he married in 1908, then contested the legacy resulting in a lengthy legal battle depleting most of the funds.
[7] Mass of Pluto [8] Strange Beleifs
A Walk In Percival's Observatory
Only A Farm Boy?
However the search continued till its conclusion with the discovery of Pluto by Tombaugh in 1930 and it seemed that from thereon, Percival Lowell would be vindicated as his calculations put Planet X almost exactly where Pluto was found. Unfortunately there was something wrong. Flash back, we already saw that in 1848 Babinet estimated for Planet X a mass of at least 12 earth masses. At the peak of the search in 1900, the estimation dropped down to 7 earth masses. As from 1930 guesses put the mass of the new found Planet at 1 earth mass. And it continued dropping; by 1960 the mass of Pluto was thought to be only of 0.1 earth mass. At the beginning of the seventies more precise estimations calibrated the planet at 0.003 earth Mass. The discovery of Charon, a giant moon of the planet by Christy and Harrington in 1978, allowed astronomers to definitively settle at 0.0021 mass Earth. It was impossible for a body with such a weak mass to influence the ice giant Neptune. This immediately raised two problems one of which was purely scientific; if it was not Pluto, then something else was causing the irregularities in the orbit of Neptune and more time would be needed to solve the mystery. As for the second question, it belonged to the realm of mysterious events in the history of Astronomy so that by what miracle, had the calculations of Lowell predetermined the location of Pluto if Pluto was not responsible for the wobbling in the path of Neptune? Was it luck? A coincidence? The benevolent smile of a cosmic joker vindicating the soul of Lowell? Mathematician and astronomer, Ernest William Brown in 1932 was already saying that the discovery was a coincidence. Luck and the human dimension of the story brings us back to modern times. Laurel Kornfeld told us that in the heat of the exchange of views ‘some’ would have said, “Tombaugh was just a farm boy who got lucky”. Though many sites define Clyde Tombaugh as a young farmer with an ardent passion for astronomy, Tombaugh was more than that![9] When he discovered Pluto on the 18th of February 1930, Tombaugh was an unlucky farm boy from Kansas who had not been able to attend college only because a hailstorm destroyed the family farm crops. Unlucky but gifted and passionate about astronomy, he built his own telescopes on the farm and got recruited by the Lowell Observatory in Flagstaff after he sent his drawings of Mars and Jupiter to them.
During the years following the discovery of Pluto, Tombaugh went on to earn a Bachelor’s and Master’s degree in Astronomy. On the page of Wikipedia about Tombaugh, we learn that during World War II he taught naval personnel navigation at Northern Arizona University. He worked at White Sands Missile Range in the early 1950s, and taught astronomy at New Mexico State University from 1955 until his retirement in 1973. In 1980 he was inducted into the International Space Hall of Fame. Clyde Tombaugh is credited with discovering 15 asteroids and observed more than 800 of them. He discovered the periodic comet 274P/Tombaugh–Tenagra as well as hundreds of variable stars, star clusters, galaxy clusters, and a galaxy supercluster. In a way, Tombaugh got lucky more than anyone on this planet as part of his ashes were mounted on the probe New Horizons which visited the world he discovered and is now hurtling at incredible speed towards interstellar space.[10]
[9] Clyde Tombaugh [10]Who Was Tombaugh?
Academy Class 1991
Venetia
"It's interesting isn't it, that as they come to demote Pluto, so the interest in it seems to have grown," "At my age, I've been largely indifferent to [the debate]; though I suppose I would prefer it to remain a planet." It is in those terms that Venetia Phair born Burney, commented on the burning question ‘was Pluto a planet?’ in a 2006 interview for the BBC[11]. At the age of 11 she had named Pluto. A few factors helped Venetia’s proposition to be chosen from among the other 1000 propositions that the Lowell Observatory at Flagstaff received. Pluto was a deity, the ruler of the underworld in classical mythology in which Venetia had an interest, other names could have fitted the bill but Pluto had the advantage to start by PL, the initials of Percival Lowell, the gentleman with unorthodox ideas who took the matter to higher levels. Venetia in her own words also had the chance to have a grand father who pursued the matter and knew Professor Turner.( Herbert Hall Turner 13 August 1861, Leeds – 20th August 1930, Stockholm) who was a British astronomer , seismologist and a professor of astronomy at the University of Oxford, one of the leaders in the worldwide effort to produce an astrographic chart.). As it turned out, Venetia’s great uncle Henry Madan had suggested the names Phobos and Deimos for the moons of Mars, so indeed the cosmic joker has his ways!
[11] Venetia Burney
Naming Pluto
Precovery
Clyde Tombaugh as we saw discovered Pluto on the 18th February 1930 but as for Neptune, pre discoveries (the correct formulation is precovery) exist and like Neptune, Pluto was not identified as a planet. In 1925 on December 23th, Mt Wilson observatory spotted the planet on two occasions and the same observatory had detected Pluto 6 years before that on December 1919. One year before his death, Lowell’s own observatory could have vindicated the man as it captured Pluto on March 19th, 1915 at 06:20:01 and in April 1915 at 04:01:03. The earliest officially recognised observation of Pluto dates to January the 23th 1914, when the Konigstuhl observatory in Germany captured Pluto at 18:58:11. There are such 16 precoverys, one of which is pointed out by Popular Mechanics[12] reporting when reporting on a precovery of Pluto dating to 1925 made by The Carnegie Institute for Science. A precovery of 1909 from the Yerkes Observatory on the 11th of November of that year is the oldest suspected picture precovered. (Yerkes Observatory also captured Pluto on the 6th of January, 1927 at 6:00:00) However astronomers still had to answer the question, if not Pluto, then what was disturbing Neptune?
The incredibly successful space probe Voyager 2 gave to mankind during her grand planetary tour finale on the 26th of August 1989, the first images of Triton. It was done during the flyby and during the first in-situ exploration by a space probe of Neptune, its rings and moon system. Triton is thought to be a once upon a time stand alone, Dwarf planet which ventured too close to the Blue Ice giant Neptune and became trapped in the gravitational grip of the giant. The clues that lead to the conclusion of this astonishing celestial kidnapping scenario are that contrary to all the major sized moons of the solar system, Triton revolves in a retrograde motion. Triton in terms of the elements that it is composed of and additionally because most major sized moons in the solar system revolve in what is considered to be normal motion called perograde, which is in the same direction as the primary object (In the Earth Moon System, Earth being the primary) does the contrary. The only plausible explanation for this is that Triton was originally part of a binary system that was captured by Neptune, resulting in the ejection of the original companion of Triton which found itself on this anomalous plane and motion around the ice giant. It is an interesting part of the whole puzzle. But Voyager 2 did not only offer a teaser as to how a dwarf Planet would look like, it also allowed in 1992 the accurate measurements made using the trajectory of the space probe revealing that the mass of Neptune had been overestimated from the beginning by at least half of earth’s mass. With this correction, the anomaly in the orbit of Uranus largely disappeared. Further more, Erland Myles Standish Jr. who made the study tracked down an error that resulted from faulty observations of Uranus made by the United States Naval Office from 1895 to 1905, but which remained unchallenged over the years.
[12] Precovery 1925 [12] Precovery 1909 [13] Planet X Fades
Voyager 2 Triton [Astrum]
Edgeworth, Kuiper
The situation seemed to be settling, even given that tiny odd ball Pluto was considered to be a planet in the solar system which contained nine planets and everyone was happy. Everyone? Not really. One of the estimations which reduced the mass of Pluto to 0.1 earth mass (1/10 Earth) was done in 1948 by Dutch Astronomer Gerard Kuiper, a man with an unusually extraordinarily accurate eyesight which allowed him to observe objects four times fainter than the normal human being can (objects of magnitude 7.5. In comparison the full moon has a magnitude of - 12.6 while the brightness of the Sun is about -26.7). In 1951, Kuiper theorized in a scientific paper about the nature of the objects that could be expected beyond Pluto “one or more small planets, like Ceres" beyond heliocentric distance r = 38 AU, and on "remnants" of a circular ring of comets being still left beyond r = 50 AU”. Despite his extraordinary visual acuity, he never himself observed this zone but as his ideas were well known among planetary scientists and astronomers, they attributed his name to one of the four major structures of our solar system (The others being the heliosphere, the magnetosphere of Jupiter and the Oort Cloud ) As it turned out, if one does want to be really pedantic, the real discoverer of the Kuiper Belt as an observer should be inscribed in the history books as Clyde Tombaugh. Here too there is a dispute as to whether it is fair to attribute to this region the name of Kuiper who had speculated that such disks could have existed in the early history of the solar system but not in its present state.
If Pluto was more massive, it would not allow by the game of gravitational interactions such a disk to exist thereby cleaning the region. Soon after the discovery, American astronomer Frederick Charles Leonard remarked “in Pluto there has come to light the first of a series of ultra-Neptunian bodies, the remaining members of which still await discovery but which are destined eventually to be detected which he wrote before the paper of Gerard Kuiper in 1943. Kenneth Essex Edgeworth, an Irish army officer, engineer, economist and independent theoretical astronomer proposed an existing disk of the nature of the Kuiper belt (1943 being the year of publication of an article in the Journal of the British Astronomical Association on the subject)and concluded with a very modern definition of the belt “ "the outer region of the solar system, beyond the orbits of the planets, is occupied by a very large number of comparatively small bodies" and that, from time to time, one of their number "wanders from its own sphere and appears as an occasional visitor to the inner solar system”. In an article in the International Comet Quarterly titled “What is improper about the term "Kuiper belt?”or, “Why name a thing after a man who didn't believe in its existence?”,[14] the author advocated rectifying that state of affairs and interestingly enough, Tombaugh himself proposed the name Kuiperoids for objects to be discovered in this region. This hypothesis of Gerard Kuiper started to become reality in 1992 with the discovery of 15760 Albion by David C Jewitt and Jane X Luu. The lambda reader, the researcher, the student and the curious will discover that this find is a landmark in the classification of Pluto and is quoted by most of the sites speaking about the subject. In a PBS nova documentary on Pluto in 2010, David Jewitt explained that it was curious for him and many others that the zone beyond Pluto seemed strangely empty compared to the inner Solar System. He would go on to say later in the same documentary “It didn't make any sense, anymore, to think of it as a planet, because it fits so well with this new population of Kuiper Belt objects”. To understand the reasoning, let’s see what the Kuiper Belt is and what it is composed of.” 15760 Albion is a relatively small object as its estimated diameter lies between 108–167 kilometres. Consecutively a myriad of these objects would be detected. One year on following the discovery of Jewitt and Luu, a few of these similar objects were added to the list and on the list ten years later, there were one thousand more. If the number accounted for today is well over 2000, it is now thought that the classical Kuiper Belt contains some 100,000 objects over 100 km of diameter. All this observational data confirmed what has long been suspected, the Kuiper belt is a region akin to the asteroid belt between Mars and Jupiter but mainly composed of a mixture of rock, water ice, methane, and ammonia. David Jewitt when inviting the then graduate student, Jane Luu, to join the research said “It we do not do it, no one will do it’. The research was extremely fastidious but it did however open a new frontier in our solar system filled with hundreds of thousands of new worlds to explore. It was at this period in time that a man entered who would be key to the whole story.
[14] Kuiper/Edgeworth?
The Kuiper Belt Nasa 360
Enter Brown
Mike Brown in his own words, “I had just finished my Ph.D. and I was looking for something new to move into. And this seemed like the most obvious thing anyone could start working on. This was an entirely new area of the solar system to go study, so it was very exciting.” The mathematics were extremely simple and it did not escape the astronomers of the time and before for that matter, that if there were so many objects in the inner region of the Kuiper Belt and even more further out, and if Pluto was one of them, then it made sense that it was only a question of time before an object bigger than Pluto would be discovered. The implications of such a discovery were that it was evident that there should be a tenth planet in the Solar System”. Finding it was exactly what Mike Brown set out to do.
The pace of the discoveries of the icy objects accelerated exponentially during the following years with objects like Quaoar which was half the size of Pluto and even bigger objects. And it would not fail as this new KBO (Kuiper Belt Object) hunt came with its own human dimension as the conflict between the Sierra Nevada Observatory in Spain and The Caltech team of Mike Brown illustrates perfectly. José Luis Ortiz Moreno, leading the Spanish team claimed paternity of the first large object discovered which qualified to be a dwarf planet after the orbit of Pluto which was later named Haumea, the Hawaiian Goddess of childbirth. Brown even acknowledged the discovery of the Spanish team initially before it was made clear that that Ortiz had accessed the logs of Brown’s own observations one day before announcing his discovery, causing clear suspicion of fraud. Nevertheless, this did not avoid Brown and his team announcing the triumph in January 2005[15] of the discovery of a world more massive and apparently larger in diameter than Pluto. As from now, the days of Pluto being known as a planet were counted down. How Mike Brown described the discovery on PBS Nova is telling “: On the day that we publicly announced the discovery, I had to make a decision. What we were going to call it? Is it a planet? Is it not a planet? Is it the tenth planet? Finally, I had to say, "Okay, it's the tenth planet…."
“…And I will tell you, when everybody kept calling me, congratulating me for discovering the tenth planet, I felt fraudulent the entire day.[16]”
The evident response to this comment is “Why?” which Neil De Grasse Tyson obviously asked to Dr. Brown whose answer is even more revealing for our understanding of the debate. “William Herschel pointed his telescope in the sky and found Uranus. Uranus is a major part of the solar system. And he found it. That is a pretty big deal. I discovered a little ice ball out on the fringe, and it just didn't seem like the same magnitude of a discovery. And I had been struggling with this for years. What do you do when you finally find one bigger than Pluto? I did not believe that astronomers had the guts to ever demote Pluto because it's just too publicly painful.”
[15] The Pluto Files [16] Brown Interview
Alan Stern
Getting To Pluto
Other astronomers arrived at the same conclusion as Brown and among the ones who for one reason or another choose to stand for the little world; Alan Stern was the most eloquent, passionate and knowledgeable about Pluto[17]. Flashback to the seventies. Initially, when Planning the Grand Planetary Tour taking advantage of a configuration which occurs every 175 years in the solar system, Pluto was considered as possible target for the ambitious program which was later scaled down to the twin probes Voyager 1 and 2. Even then, Voyager 1 could have reached Pluto but the decision to optimize its path to a maximum making a flyby of Titan, a planetary sized moon of Saturn with a dense atmosphere put Voyager 1 on a trajectory which would not allow it to reach Pluto. Alan Stern was not of the generation which conceived and launched the Voyagers. Instead, people like Gary Flandro, Edward Stone, Bradford Smith, Carolyn Porco or Laurence Soderblom were and they will for ever be associated with planetary exploration. But Alan Stern proved that the following generation of planetary explorers were as worthy as their predecessors. On June 14, 2007, in an address to the Smithsonian Institute for their "Exploring the Solar System Lecture Series", Stern commented: “I recall going to JPL, the Jet Propulsion Lab, in the summer of 1989 when I was in graduate school to take a summer course in planetary exploration at Caltech and this was the summer of the Voyager fly-by of Neptune and Triton (which had turned out to be rather a twin of Pluto). It was amazing to get to be a part of some first-time exploration like that! Within a matter of months, a small group of us had formed a team, an advocacy group, Why don't we get a mission together for Pluto?”
Alan Stern has a biography that is most impressive, and if Pluto is an outsider in this cosmic match, Stern is more of a heavy weight. Two times he was proposed as potential mission specialist/Astronaut on the Space Shuttle though he never flew in Space. Stern has been involved in 24 suborbital, orbital, and planetary space missions, including eight for which he was the mission principal investigator. Alan Stern was listed in 2007 by Time magazine among the hundred most influential persons in the world. He earned a doctorate in astrophysics and planetary science from the University of Colorado, Boulder. As NASA’s associate administrator for the science mission directorate, he was to
become the overseer of a 4.4 billion dollars budget for 93 separate flight missions and an added program of over 3,000 research grants.
Alan Stern created with a group of scientists and engineers, Fran Bagenal, Rick Binzel, Marc Buie, Bob Marcialis, Bill McKinnon, Ralph McNutt, Bob Millis, Ed Tedesco, Larry Trafton, Larry Wasserman, and Roger Yell, the Pluto Underground which was akin to the Mars Underground and which proved successful in the renewal of interest in Mars exploration by advocating for a mission to the distant world. At the time they were frustrated by the decision not to send Voyager to Pluto but later with insight, Alan Stern went on to say on many occasions that it was the best decision to take at the time. For decades, they continuously championed multiple projects which never left the drawing board, the Pluto Kuiper Express, Pluto 350 or the Mariner Mark 2 spacecraft. They found concepts which were studied and rejected one after the other and sometimes they went to a large extent to avoid the scrambling of a project. One project named The Pluto Flyby rapidly raised budget concerns among others and despite scrapping the Twin explorers by scaling it down to only one probe, the project was still too expensive. The original project was a radical concept of a flyby by 2 space probes weighing 35 to 50 kilograms each carrying only 7 kilograms of scientific instruments each. Facing cancellation, Stern cut a deal with the Russian Space Research Institute which would launch The Pluto Flyby atop a Proton Booster, would piggyback it on the trip of an atmospheric probe from Russia which would impact the planet making it the last outpost of the human species in the Solar System, an honour which is held today by the European probe Hugyens on Titan which safely landed on Titan by piggy backing on the Cassini spacecraft which studied the planet Saturn and its system after entering orbit on July 1, 2004.
Those who lived during this intense period of struggle will also remember the intense lobbying of the Planetary Society which triggered a hammering lobbying campaign to visit Pluto in-situ by addressing ten of thousands of letters of support from the public to the senators and representatives on Capitol Hill, organising public meetings in Washington and testifying in front of the Congress. The Planetary Society was a determining factor in helping to avoid delays in the Launch of New Horizons.[18][19]
[17] Pluto a Planet [18] Interview YT [19] Chasing New Horizons
Triton, A Cousin?
In 1992, the same year that the Kuiper Belt object Albion was discovered initiating the rush to scan this region of the Solar System, Clyde Tombaugh received a phone call from a man named Robert Staehle, the President of the World Space Foundation. With a JPL Engineer Stacy Weinstein, they assisted with issuance of a postage stamp by the United States Postal Service on October 1991 commemorating NASA’s exploration of the solar system. The two men were impressed by the caption on the Stamp dedicated to Pluto, it said “Not yet explored’ so they put out the word to change this ‘not explored’ status and enquired about the feasibility of such a mission. His call to Tombaugh was to request from the Astronomer, the permission to visit the planet he discovered. To which the aged planet hunter answered “You are welcome to it”.
Mike Brown in the interview for PBS described (as mentioned previously in this article ) his discovery (which came to be the main fatal blow to the status of Pluto) as the discovery of a little ice ball. And it is exactly in those terms that the denizens of this far flung region of the solar system, a region beyond Neptune full of icy bodies left over from the early solar system, were commonly described up to the end of the 1990’s. As we saw the flyby of Triton[20], a satellite of Neptune by Voyager 2, gave an impetus to the case for Pluto. The seventh-largest moon in the solar system Triton was revealed to be a planetary sized moon with intense geological activity and is bigger than Pluto with a diameter of 2706.8 kilometres, exceeding the one of Pluto by 330.2 kilometres. Triton has active geysers and other features making it one of the few geologically active moons of the solar system, it has a surface composition of nitrogen, methane and water ice. It is mostly water-ice crust with an icy mantle and a substantial core of rock and metal. Voyager 2 registered temperatures of -235 Celsius 38 K. It has Tectonic activity as well as Cryovolcanos, relatively few impact craters with a dynamic atmosphere albeit tenuous extending 800 kilometres above its surface. It is uncertain when Triton was captured and how long it took for the moon to settle in its current orbit but this process would have put Triton under tidal stresses thus producing heat. This mechanism powers the 400 known volcanoes on the hellish moon Io orbiting Jupiter as well as allowing the existence of several subsurface oceans around Jupiter and Saturn moons. The same kind of tidal heating could have created an ocean underneath Triton’s ice shell, a subsurface ocean which some researchers think could still have survived to this date and is composed of water mixed with ammonia.However,despite all the promising discoveries made on Triton, it was still possible that all this geological activity was only the result of the chaotic capture by Neptune and the influence that the ice giant still has today on her. To be sure, it became more and more pressing that space probes visits a KBO (Kuiper Belt Object) like Pluto so as to ascertain the facts of the matter.
On July the 29th, 2005, the Team of Mike Brown, Chad Trujillo, and David Rabinowitz announced the discovery of the sixteenth most massive object in the solar system including the moons and the ninth most massive known object directly orbiting the Sun, it was baptized Eris[21]. In 2016, a large moon was discovered orbiting Eris ,named Dysnomia and is of 2021, the second largest moon revolving around a Dwarf planet with an approximate diameter of 700 kilometres (+/- 115 kilometres), even larger than the famous subterranean ocean world, Enceladus, orbiting Saturn. Eris ventures far out at the confines of our solar system. Considering that Neptune is the latest officially recognised Planet of the solar system and is situated at 30 Astronomical Units from the sun (An astronomical unit is a geocentric measure base on the average distance between the Sun and Earth 150 million kilometres) then Eris at his closest to the sun is 38 AU. This means that the distance that separates Eris from Neptune at its closest, equates to 8 times the distance between the Sun and Earth! At its furthest, Eris find herself at the mind boggling distance of 97.5 AU, more than three times the distance between Neptune and the Sun. The Dwarf Planet takes 559 earth years to complete an orbital rotation around the Sun.
[20] Unlikely King [21] Eris Facts
Eris Facts & History
New Horizons & the IAU
Alan Stern is certainly the person who personifies the New Horizons mission. But when in 2000, he was appointed project investigator of the Team New Horizons which he formed with Stamatios (Tom) M. Krimigis who had contributed to almost every exploration mission to the planets of our Solar System, the battle to explore Pluto was far from being won. Even after being officially funded, New Horizons was effectively cancelled by NASA’s administrator Sean O'Keefe and not included in NASA’s budget of 2003. A new campaign of lobbying started headed by the indefatigable Stern for funding the probe but also for the project to appear in the Planetary Science Decadal Survey; a prioritized "wish list", compiled by the United States National Research Council, that reflects the opinions of the scientific community. (Source Wikipedia). This was successfully achieved as the New Horizons probe topped the list of the surveys for missions having top priority for the period 2003 to 2013. Finally after decades of debate, arguments, projects that never left the drawing board, protests, congress hearings and intense judicial procedures (Stern & David Grinspoon's 2018 book, "Chasing New Horizons."), New Horizons was ready for launch atop its booster on January the 19th, 2006. Alan Stern described the whole period in an interview on space.com in 2018 “ But I think New Horizons is one of the longest and most involved, politically intriguing sagas in the history of planetary exploration, particularly for a first mission to a new planet. “
When New Horizons freed herself from both Earth and the Sun’s gravitational grip attaining the velocity of 58,536 kilometres per hour, (36,400 miles per hour) it was the highest launch velocity attained by a human-made object relative to Earth. She was carrying a package of seven scientific instruments dedicated to unveiling the secrets of Pluto (Ralph-Visible and Infrared Imager/Spectrometer, Alice-Ultraviolet Imaging Spectrometer, Radio-Science Experiment (REX),Long-Range Reconnaissance Imager (LORRI),Solar Wind and Plasma Spectrometer (SWAP),Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI),Student Dust Counter (SDC)) and part of the ashes of Clyde Tombaugh) but also the hopes, endeavours and dedication of several generations of illustrious astronomers and planet hunters since the discovery of Neptune to maverick engineers and a new generation of today’s planetary scientists.
On June the 13th, 2006, New Horizons was well beyond the orbit of Mars and performed calibration and testing of its instruments during a brief encounter with Asteroid 132524 APL. However, 71 days later, the planet that she had been dedicatedly designed to explore was no planet anymore, based on a decision taken on August 24th, 2006 when the International Astronomical Union demoted Pluto from its planet Status to the great satisfaction of some and the extreme displeasure of others. The unaware reader will be surprised that before AD 2006, there was no proper definition of a planet. A planet is one of those things that the ancients named and that mankind was very happy to live with until turbulent astronomers decided to question the matter. However, some Astronomers seemed to think that the matter was pressing as the pace of Trans Neptunian discoveries would soon exponentially increase the number of planets in the Solar System.
Part of the IAU announcement reads as follows …. This means that the Solar System consists of eight “planets” Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A new distinct class of objects called “dwarf planets” was also decided. It was agreed that “planets” and “dwarf planets” are two distinct classes of objects. The first members of the “dwarf planet” category are Ceres, Pluto and 2003 UB (temporary name). More “dwarf planets” are expected to be announced by the IAU in the coming months and years. Currently a dozen candidate “dwarf planets” are listed on IAU’s “dwarf planet” watchlist, which keeps changing as new objects are found and the physics of the existing candidates becomes better known.
To clarify and make a general breakdown, the criteria for a celestial object to be raised to the envious and glamorous status of planet are.
“….that a “planet” is defined as a celestial body that (a) is in orbit around the Sun,
(b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,
and (c) has cleared the neighbourhood around its orbit. “
Pluto is round in shape and orbits the sun but her environment is messy and that’s the heart of the problem.
[22] Controversial Decision [23] Debate Stern-Eckers
Stern on Event Horizon
Ceres & Pluto Unveiled
Mike Brown was thinking apprehensively before the decision of the IAU, he said “What do you do when you finally find one bigger than Pluto? I did not believe that astronomers had the guts to ever demote Pluto because it's just too publicly painful” Afterwards with the release following the announcement he added “In the definition that the I.A.U. came up with, eight major things which dominate the solar system are planets. They're all big. They go in circular orbits in one disk around the sun. And everything else is all in these other crazy orbits, much smaller. Those are not planets. That concept is a rock-solid concept“. But was it?
For many it certainly was not and the pro Pluto resistance went without transition onto the offensive defending their preferred planet with all the means available. Several books were published; conferences, blogs, dedicated websites and debates were organized in schools and universities using any means available to make their voices heard. Many astronomers even publicly asserted that they would continue calling Pluto a planet even going as far as signing petitions. But if the blow given by the IAU to the pro Pluto camp was not the end game, it was however devastating not because it was a solid concept like Mike Brown had asserted but for many in the public who know very little in matter of celestial affairs, the endorsement of a group of astronomers under the banner of an organisation which includes the word International and Union settled the matter, but we will come back to that.
After New Horizons flew by Pluto in 2015, there was a revival of the interest in the public with articles asking if Pluto was a planet after all? This flourished again on the internet but how better to describe this than by the words of Stern himself that one can read on his website, ” Nothing like this has occurred in a generation—a raw exploration of new worlds unparalleled since NASA’s Voyager missions to Uranus and Neptune—and nothing quite like it is planned to happen ever again. The photos that New Horizons sent back to Earth graced the front pages of newspapers on all 7 continents, and NASA’s website for the mission received more than 2 billion hits in the days surrounding the flyby. At a time when so many think that our most historic achievements are in the past, the most distant planetary exploration ever attempted not only succeeded in 2015 but made history and captured the world’s imagination”. The scientific data inflamed the imagination of the public and then of course, the enthusiasm dropped. What is the state of affairs? Is it over? Had the idea of Pluto not being a planet already sunk in? We asked Laurel Kornfeld the question.
” Mike Brown claimed that all but a small minority of planetary scientists have come to accept the IAU definition. He has stated that the only scientists who want to keep Pluto a planet are those on the New Horizons team which is very controversial adding that they can't deal with visiting something that isn't a planet and even accused members of the NH team of not really believing their own position but using it just to boost the prestige of the mission”..Laurel Kornfeld also told us about the theory that it was all over,
“Many people, ranging from scientists to amateur astronomers to members of the public, changed their views to support Pluto's planet status as a result of New Horizons' findings, which showed Pluto to be a geologically active world rather than the dead rock many expected”[25]. An interesting remark she made was that “Furthermore, in science, doing things the right way takes a long time--years or even decades”. Rightfully so, there is a story that perfectly fits the bill to illustrate this comment.
Four months before the arrival of the New Horizons probe to Pluto, the Dawn Mission, a spacecraft powered with ion engine propulsion went in orbit around the dwarf planet Ceres. Ceres was revealed to be geologically active while some data even raised the suspicion that she once harboured a global subsurface ocean. Some argued that this ocean or large pocket remnants could still persist though some think it is wishful thinking. Planetary Scientists believed that Ceres would have migrated from the far regions of the solar system before settling in her orbit in the asteroid belt between Mars and Jupiter. In a spectacular demonstration, Ceres proved that those small worlds had an identity of their own and they were something more than big dead asteroids interacting only with the flux of solar particles or undergoing drastic modifications in their structure when impacting another object. However what is interesting with Ceres is her changing of status in historical times.
[24] L. Kornfeld's blog [25] Dawn's Mission
Pluto & Beyond
Classification Waltz
Laurel Kornfeld pointed this out to us after having gone through more than 15 yrs of blogs on the subject. At a point, Neil De Grasse Tyson commented that people must “grow up” but according to her, this does not make sense for a scientific educator and hides the true issues. “I do think telling people to ‘grow up’ and accept the change in Pluto's status is condescending and diminishes the fact that there is an actual, scientific debate, not just over what Pluto is but on how to define the term planet. It is worth noting that Tyson is a galactic astronomer, not a planetary scientist”. According to her, the other reason behind the position taken by Neil De Grasse Tyson is explained by the fact that, “Regarding Tyson, he clearly plays the role of entertainer and showman as well as educator. Some of his comments are tongue-in-cheek or meant to be light-hearted and generate laughter. He has been inconsistent in his statements about Pluto. Alan Stern has Tyson on audiotape saying he has no problem with dwarf planets being considered a subclass of planets.”
As we said, Dwarf planet Ceres could be a case study for those who think that the matter has ended. Around the year 1772 the cosmic joker was having a ride. Astronomers of this time were hunting for a planet X but this time, they were looking for a missing body between the orbit of Mars and Jupiter, convinced and encouraged by the now disapproved Titus Bode Law which correctly predicted both the position of Ceres and Uranus but failed to predict Neptune. In 1800, the German astronomical journal Monatliche Correspondenz (Monthly Correspondence) under a group headed by editor Franz Xaver von Zach organized a group of 24 experienced astronomers to hunt for the missing planet and though they did not find Ceres, they did discover asteroid Pallas and Juno and more notably Vesta, a proto planet with a diameter of 525 kilometres. Ceres was discovered in 1801 by Italian Giuseppe Piazzi, a catholic priest who was also a mathematician and astronomer. The new world was listed as a planet in astronomy books and tables for the next half a century before the discovery of many other objects in its neighbourhood prompted astronomers to classify her in a new group called asteroids. During the time of the same announcement that demoted Pluto, Ceres with its diameter of 939.4 kilometres jumped back from being a mere asteroid to the closest dwarf Planet to Earth and the only one in the inner orbit of Neptune.[26]
[26] Ceres [26A] Alan Boyle
Tyson, only a comet!
A Geophysical Definition
Laurel Kornfeld also argues that the abundance of articles published both preceding and after the IAU decision, proved in itself the dynamism of the Pro Pluto movement rather than the mediocre coverage and among the ones she quoted was an alternative to the IAU definition of a planet presented by planetary geologist Kirby Runyon to the Lunar and Planetary Science Conference in March 2017. Quoting Kirby, “we, as planetary scientists, find it useful to define a planet as a substellar mass body that has never undergone nuclear fusion and has enough gravitation to be round due to hydrostatic equilibrium, regardless of its orbital parameters. This is the definition we presented at the 2017 Lunar and Planetary Science Conference. Indeed, planetary scientists already use and teach such a geophysical definition of planet to promote a useful mental schema about the round and non-round worlds we study: At least 119 peer-reviewed papers in professional and scientific journals implicitly use this definition when they refer to round worlds (including moons) as planets. The artificial authority behind the few voted definitions in existence, such as the IAU’s planet definition, should be viewed with scepticism and even dismissal”. As one can, see the gun is still loaded and pointing in the IAU’s direction.
However if the layman has arrived here in the article and for some reason has been interested enough to go on to a higher level than this present piece which is more in the category of general knowledge, Laurel has directed us towards the excellent article of Dr.Phil Metzger on April 13, 2015 titled ‘Nine reasons why Pluto is a planet’ which is an easy read while presenting hard scientific evidence and information with straight forward and obvious conclusions . Despite the excellence of the article by Dr. Metzger and the irritation that one could feel he has against the IAU decision, reading the sentence that appeals the most and maybe gives all the reasons for the debate is “Shoving them out from planet status has tended to push them from the public’s consciousness and thus it has reduced the excitement of discovery”. It could not has been better put as the aim was and always will be, to open the consciousness of people against perpetuating their ignorance. If Laurel Kornfeld manages to explain the reasons behind Neil De Grasse Tyson with some understanding for the scientific educator and populariser, Dr Metzger gives him no space to blunder, bluntly attacking gross scientific inaccuracies from Tyson about Pluto. This extract is epical and we quote”Neil de Grasse Tyson also says, Pluto is my favourite comet. He says that because of Pluto’s ice content, if it were put as close to the Sun as the Earth, then it would grow a tail. That’s no kind of behaviour for a planet’. He says, “Planets don’t have tails. Thus, since it behaves like a comet, it must be a comet”. This “Pluto would grow a tail like a comet” meme is factually incorrect – a violation of physics – and unfortunately it’s repeated all over the Internet and it’s even in Wikipedia in an article about Pluto. (Wikipedians: go fix that!).It doesn’t matter that Pluto is partially ice. It’s only about 30% ice (by mass) while the other 70% is rock, but that’s neither here nor there. Planets can be made out of rock, metal, ice, liquid, or even gas. And planets with any of these materials can form a tail if put close enough to a star. We actually know of some exoplanets that have tails. However, Neil makes a great point that we should classify bodies according to their prototypes. If Pluto were to behave prototypically like a comet, then maybe it should be classified as a comet. But if it behaves prototypically like a planet, then it should be classified as a planet."
We can conclude a few things about the incident with Tyson. First, everyone has to cross reference information and no one is immune from mistakes. But in the case of Tyson, it is unacceptable not because of the sphere he dwells in as Laurel pointed out but because Tyson despite being an astronomer and not a planetary scientist has a role of educator in the media. Worse still, when you look at it his mistake, it can be explained only by intellectual laziness as Neil de Grasse Tyson has far more intellectual capacities than needed to figure out the truth about the comets.
As we saw, the issue of clearing the neighbourhood is the main problem for Pluto, this process describes how a celestial body gradually becomes gravitationally dominant such that in the zone, there is no object of comparable size other than itself and its natural satellites.
There are several problems to include in the process of gravitational dominance as criteria to define a planet. The IAU decision also fails to take into consideration objects like ‘Rogue Planets’ which are planets ejected from their original star system , it also fails to include the exoplanets too, though In 2015, a proposal was made to extend the definition to exoplanets. The IAU definition is also very counter intuitive as in many cases, what would be considered a planet around one star system would not be considered as such in another star system. In other terms, the IAU teaches us that being a planet does not depend only of the physical characteristics of the object but its location. If you want to know how absurd it can be and see an example how Earth would not be considered as a planet in another star system, we refer you again to the article of Dr. Phil Metzger where he explores some of these possibilities. Quoting Alan Stern to show how it does not even make sense to apply it to our own solar system, Stern argued that the IAU's wording is vague, and that — like Pluto — Earth, Mars, Jupiter and Neptune have not cleared their orbital neighbourhoods either. Earth co-orbits with 10,000 near-Earth asteroids (NEAs), and Jupiter has 100,000 trojans in its orbital path. "If Neptune had cleared its zone, Pluto wouldn't be there", he said.
We will not debate the policies of the IAU and the voting procedures which unfortunately are at the heart of the problem since the aim of this article is to determine what is correct scientifically, not the way human administration and structures operate or function. Would you be correct if you say that Pluto is a planet? Well yes you will be. Even better! When quoting people and studies we refer to, the chances are that it is you who will convince the other party to change their opinion.
[27] Nine Reasons t
Geophysical Definition Kirby Runyon
Planetary Size Moons
Concerning Mike Brown, Laurel Kornfeld is less understanding and having met Tyson she said of him,"...... While at least some of Tyson's comments are intended as jokes and one liners, I have met Tyson, and we can joke about our differences of opinion.....” The situation with Brown is more of an explosive nature. “Brown seems to have strongly invested his career and identity into being the man who ‘killed Pluto.’ Brown has made some very controversial statements, such as claiming that all but a small minority of planetary scientists have come to accept the IAU definition. He has stated that the only scientists who want to keep Pluto a planet are those on the New Horizons team because they can't deal with visiting something that isn't a planet and even accused members of the NH team of not really believing their own position but using it just to boost the prestige of the mission”. (N.B Laurel Kornfeld never met Dr Brown but they have in the past exchanged emails).
Commenting on the proposition to again redefine the status of Pluto, Mike Brown said in the article by Mike Wall on Space.com on the 22 of February, 2017 ‘Will Pluto Get Its Planethood Back?’ “….Oh God, the stupid Pluto stories are back. Yes, someone has proposed making Pluto a planet again. No, nothing is changed or new" Brown tweeted on Tuesday, February the 21st. “Also; I should note that proposal would make the moon a planet. This is about 500 years out of date. But, ok #MakeTheMoonGreatAgain,"
Well yes[28], we should make the moon and some other moons in the solar system great again. Why? Voila pour quoi. Commenting on the fateful decision of the IAU, Alan Stern once said “It is a scandal, it would have never passed peer review!” However what has passed peer review were articles pre and post the IAU announcement describing large moon like ‘Planets’. Actually very often across the internet they are referred to as a planetary sized moon which is a fairly correct way to describe these objects. And here again, there are worlds like Io, the size of our moon constantly remodelling its surface due to the more intense volcanic activity than that of any other world of the solar system or Callisto, Europa, Ganymede & Enceladus harbouring sub surface global oceans each individually containing more liquid water than the combined oceans of Earth. Those worlds orbiting the worlds of the gas giants, Jupiter and Saturn are extremely promising candidates for harbouring life since at least many of them offer promising conditions for life to emerge. Having a sub surface ocean is a characteristic that they seem to share with some of their cousins, the dwarf planets due to a surface geology mainly dominated by Ice, albeit of a different composition. Ganymede sports a diameter of 5,268 kilometres, which is 26 percent larger than the fully fledged planet Mercury. Ganymede exhibits another very planetary aspect as it is the only moon to have its own home-grown magnetic field which produces auroras albeit dubbed the weirdest magnetic field in the solar system as it has a unique shape, possesses no plasmaphere, has no radiation belt and has no bow shock. Furthermore, planet Ganymede which is a moon of Jupiter possesses the only magnetosphere embedded inside another magnetosphere.
How can someone not be convinced when facing Titan which is a Planetary sized moon which is also larger than Mercury, has a denser atmosphere than the one on earth and like earth, it is primarily composed of nitrogen. Titan has on its surface, lakes of hydrocarbons, and is the only world along with Earth to have sizable areas of stable liquid bodies on the surface, a feature that does not exist on Mercury, Mars or Venus. It is also possible that the biggest planetary sized moon of Saturn contains under her surface, a global ocean for which several models exist and the composition of the ocean could be of liquid ammonia or a mixture of water and ammonia. Titan presents a fertile terrain for research on prebiotic conditions and could well be a candidate for harbouring life too. Some like Chris McKay have proposed models showing how Titan could be the home of a second genesis. The other types of the population of moons are potatoid in shape and could be more aptly called an asteroid type moon.
In fact if someone wants to be very pedantic, the new definition of the IAU should not even include Jupiter as being a planet. The mighty Jupiter with a gargantuan magnetosphere which is ever mightier than the Sun’s is almost a mini solar system of its own and is accompanied during the her roundtrip of 12 years around the sun by four planetary sized moons and 75 more smaller sized moons. Someone once said that the solar system is composed of only two objects, the Sun and Jupiter so that one can illustrate the predominance of the lord of the planets of the solar system over all the other denizens. Jupiter's mass is 2.5 times that of all the other planets in the Solar System combined, Jupiter is so massive that its barycentre (In astronomy, the barycentre or barycenter is the center of mass of two or more bodies that orbit one another and is the point about which the bodies orbit. A barycenter is a dynamical point, not a physical object. It is an important concept in fields such as astronomy and astrophysics.) with the Sun lies beyond the Sun's surface at 1.068 solar radii from the Sun's center making Jupiter have more of a binary relationship with the Sun. Both the Sun and Jupiter orbit around that point above the Sun’s surface. Reporting during the first stages of the Juno mission to Jupiter on the 19th of July, 2016, Rafi Letzter writing in an article for the Business Insider said, “Forget what you heard, Jupiter does not orbit the Sun.”. The paper is a very accessible one explaining simply this state of affairs of the Jovian system.
[27] Puzzling Moons
Brown. How I Killed Pluto
Pluto-Charon Binary System
Alan Stern proposed to compare a tiny sized dog to one of a different breed but bigger in size and concluded that it is a good way to view the matter. Most of the sites speaking about Alan Stern and his position about Pluto refer to the Star Trek test that he coined which defines our intuitive way to judge if a celestial object is to be recognised by us as a planet. In a sense it is true, the best way to convince yourself if Pluto is a planet is to revisit it. If you have not already done so, the images that New Horizon transmitted to Earth allow you to discover how Pluto is not only a Planet but a spectacular one. If pedantically speaking we can say that Jupiter is in a binary relation with the sun, then Pluto and her moon Charon are in a proper binary planet system relationship and so far, this relationship is the only one known in the solar system. Charon’s barycentre lies around 960 kilometres above the surface of Pluto and orbits at a distance of some 19,640 kilometres from it. Charon is enormous compared to its parent planet Pluto being about half of Pluto’s size with a diameter of 1200 kilometres and if Charon is seen as a standalone object orbiting the sun, it would have been considered a Dwarf planet. Charon is even thought in the past to have been able to sustain a subsurface ocean and possesses some extraordinary features such as a canyon four times the length of the famous Grand Canyon in the United States as this scar stretches for 1600 kilometres across the surface. At a distance of only 19,640 kilometres from Pluto, the system is sometimes referred to as a double dwarf planet. Because both objects truly orbit the other, and Charon has 12.2% the mass of Pluto, it has been argued that Charon should be considered to be part of a binary system with Pluto. The International Astronomical Union (IAU) states that Charon is considered to be just a satellite of Pluto, but the idea that Charon might be classified as a dwarf planet in its own right may be considered at a later date.
As in a chapter of a science fiction book describing an alien world, there is an unusual transfer of material from Pluto to Charon. Observing Charon when flying at its closest to it at a distance of 27,000 kilometres, the New Horizons probe noticed a red formation spread over the North Pole; surprisingly the material was composed of nitrogen and carbon dioxide and comes from the tenuous atmosphere of Pluto which escapes it. Some of this material crosses the space between the two planets and accumulates around the North Pole region. Charon always faces the same side to Pluto as there is only one side continuously visible of Pluto from Charon because the Double Dwarf planet is locked in what is called an extreme mutual tidal locking. Compared to the system Earth/Moon, it differs by the fact that though we see only one side of the moon from Earth, all the sides of our planet are visible from our planetary sized satellite, the Moon. Once Alan Stern explained that if you can blot out the full moon with your thumb if you extend your arm standing on Earth, you will however need your full fist to blot out Charon in the sky of Pluto.
Pluto the dwarf planet with disputed status is orbited by four other small moons, Styx, Nix, Kerberos, and Hydra. ranging from 7 to 55 kilometres on their longest axis.
Speaking of size, Pluto is very often referred to as tiny, small and the adjective little is often attached to it. Small is however relative, for one to figure out how big Pluto is and make sense of it, let’s speak about the surface area of Pluto. Earth’s surface area is some 510 million square kilometres, Venus which is about 90 percent of Earth’s size has a surface area of 460 million square kilometres, but on earth only 29 percent of the planet is covered by land meaning that the total land surface available has a value of 149 million square kilometres. Mars for instance with 144.8 million square kilometres of surface area despite being smaller, would have almost the same land area available as on Earth due to the lack of large bodies of liquid occupying the surface .Our Planetary sized moon sports an honest 38 million square kilometres which could easily contain the Australian continent, in fact the moon is 6.5 million square kilometres short to equate to the surface area of Asia. Pluto with 16.7 million square kilometres is almost the same size as Russia and Russia is a vast territory with one ninth of the world’s land mass and 11 time zones and of course contains a variety of geological features like mountains, rivers, lakes etc.
With a diameter of 2373.6 kilometres, Pluto is the first dwarf planet of the Kuiper belt whose inner edge starts at the orbit of Neptune situated at 30 AU from the Sun. Much more dynamic than ever expected, Pluto has peaks towering 3500 kilometres high. Though a sub surface ocean was suspected, cracks[28] found on the ‘Dark’ side of the planet reveal that contrary to assumptions that the ocean of Pluto had a ‘cold start’ which means that the ocean started frozen at the beginning and then gradually heated up with radioactive decay is not correct. The cracks found show evidence of expansion and not contraction that only happen when the crust is moving apart from each other. If Pluto had a hot start, the following question is where the heat came from? It could be that Impacts caused by the multitude of icy bodies present in the region where Pluto was forming, generated the heat. If that is the case, Pluto could have had a surface ocean far back in her history and evidence to support this assertion is a frozen lake which seems to have channels nearby it and is pictured on the images from New Horizons. It would mean then that in a distant past, the atmosphere of the Planet could have been 40 times denser than the atmosphere of Mars.
Today’s atmosphere on Pluto is very tenuous and as we saw, is not even able to retain the particles escaping the planet on their journey to the Moon Charon. The main constituents of this atmosphere are nitrogen, methane and carbon monoxide and Pluto’s atmosphere undergoes a cycle where its density varies. This phenomenon is due to the sublimation of ice directly into gas which replenishes the atmosphere when Pluto is at its closest point to the sun. The process reverses when Pluto finds itself at its furthest point to the sun. This atmospheric yoyo game has led some to present Pluto as a gigantic comet but Pluto retains an atmosphere during all the time of her revolution around the sun. The atmosphere is even capable to generating winds. Clouds may have been spotted on the images of New Horizon as per an announcement of the NH team in 2016. Methane which is a green house gas, induces the upper atmosphere which extends 1600 kilometres above the surface to be warmer than the surface temperature. No one speaks about Pluto without mentioning the heart of Pluto. This region’s official name is the Tombaugh region and this unique feature in the solar system has the structure in the shape of a heart and is 1590 kilometres across. The western and eastern parts of the lobe have a different geological story.
The western lobe of the Tombaugh region is named Sputnik Planitia and is an Ice filled basin that covers an area of 1050 kilometres by 850 kilometres in size. It is devoid of impact craters which imply that the formation could not be more than ten million years old which is relatively young on the geological time scale. Some models based on sublimation give an approximate surface age ranging from 140,000 years ago to 270,000 years ago.
Though there are alternative propositions regarding its formation, the most accepted explanation is that the basin was probably created by an impact caused by a hypothetical impactor of a size ranging from 150 to 300 kilometres. The Impact basin would have collected the ice volatiles slowly filling the depression,. Sputnik Planitia is an effective cold trap, the colder air strengthens while circulating in the basin and the higher pressure noted at the surface is partly due to the accumulation of kilometres (some estimates put a depth of 3 kilometres but at least 1kilometre) of ice in the basin. It seems that Sputnik Planitia adds more complexity than otherwise suspected to the atmospheric dynamism of the dwarf world. A thin layer of the nitrogen Ice covering Sputnik Planitia sublimates passing without transition to its gaseous state, then during the night condensation occurs thus causing a cycle of nitrogen winds around the planet. Not content to play the role of atmospheric regulator, the center of the formation is situated very close to the tidal axis (an imaginary line linking Pluto to Charon) which could have played an important role in the extreme mutual tidal locking between Pluto and Charon.
Another mind boggling feature which occurs on Pluto is a belt of sharp shreds, evenly spaced apart by a few kilometres sometimes as lengthy as 30 kilometres, made of nitrogen ice which go around the whole planet, some of them cumulating at 1 kilometre high and rising in the sky as drawn blades. Pluto is simply a festival of geological features and some are on a gigantic scale and more importantly, it has active geological features like cryovolcanism.
[28] Pluto Facts
The Whole Mission New Horizons
Eris, Sedna, Scattered Disk
For the partisan or reintegrating Pluto, the fight is far from over but they know that like Laurel Kornfeld says, science matters take time. As for the IAU decision even though they have at many times explained their procedures, one cannot help think that this decision was more around how to make Pluto and its kind not a planet rather than find a proper definition for a planet. Worse, if it was in their intention to make the matter simple, then adopting this anthropomorphic definition of planet made the matter worse for the educator creating confusion and who now has to battle between definitions to effectively deliver the information. At a moment in our interview Laurel remarked “Neil de Grasse Tyson is not a planetary scientist” which we think relevant, Wikipedia in its page on dwarf Planets says “Thus Stern and other planetary geologists consider dwarf planets to be planets, but since 2006 the IAU and perhaps the majority of astronomers have considered them to be a different category of object.” Any one having any brain cell working and capable of some logic can decide from this simple sentence as it is easy to decrypt, much as one should take advice from a dentist when having issues with his teeth and not from his cardiologist even though the latter may have excellent insights in the matter.
Though the world of science is like any other human activity shaken from time to time with disagreements, that is how progress works, eventually scientific truth and reason will prevail but it may be not for a long time before the small planet makes a come back in the big boys cosmic playground. Unless we get some help from ….. the cosmic joker as the hunt for planet X is on again lead by Mike Brown. The proposition for an unaccounted massive planetary sized object in the Kuiper belt was put on the table many times notably to explain the low amount of sizable objects in a dynamically unstable region of the Kuiper belt called the scattered disk where short term and periodic comets originate from. The scattered disk overlaps the Kuiper belt and extends to beyond 100 AU. Eris which contributed to the downfall of Pluto and was thought to be larger than the latter was finally found to be smaller but still denser and is considered to be part of the scattered disk. It is possible that we will discover objects of such larger sizes than Mercury or Mars in this sparsely populated region that it will again raise the question of the reclassification of Pluto and most generally of all dwarfs planets even though a survey by Mike Brown in this region has not revealed objects of one Earth mass. But Mike Brown is after another fish, a far bigger one.
[29] Planet 9 Batygin.
Planet 9 Is It out There?
Planet X
Sedna is a dwarf planet with an exceptionally long and elongated orbit, taking approximately 11,400 years to complete a revolution round the sun. Sedna at its furthest is at an insane 937 AU. Discovered by Mike Brown, Sedna is currently placed by The Minor Planet Center in the scattered disc . Perturbation in the orbit of Sedna and other objects discovered afterwards and presenting the same anomaly (19 to this date) has lead Mike Brown and his colleague Konstantin Batygin to conclude that an object five to ten times more massive than earth is pulling gravitationally on Sedna and its consorts. Is this planet X real? And will it be found? Only the future will say. In the mean time, the Mythology student will may well explain to you that Brown like Sisyphus or Cassiopeia has angered the gods by diminishing the role of Pluto and has thus been cursed to the never ending search to find planet X.
[30] Sedna Dwarf Planet [31] Why No One Saw Planet 9?
