Nineteen Years Later, the Pluto Resistance Continues

 

Nineteen years. That is how much time has passed since the controversial IAU vote in 2006. Planetary science has been in a long-term stalemate over the issue of planet definition. The IAU refuses to re-open the debate based on new information, including that returned by New Horizons. At the same time, a large number of planetary scientists are using the geophysical planet definition and ignoring the IAU altogether.

The conference “Progress in Understanding the Pluto System: Ten Years Since Flyby” focused heavily on the planetary characteristics of not just Pluto, but also Eris, Ceres, Makemake, Neptune’s moon Triton, Saturn’s moons Enceladus and Titan, and Jupiter’s moon Europa.

It also included presentations on the persistence of scientists in terms of Pluto’s discovery and in terms of getting the New Horizons mission off the ground.

The term “planetology,” now another name for planetary science, was first coined by the late Percival Lowell, who began the search for a planet beyond Neptune early in the last century.

In 1915, Lowell published “Memoir on A Trans-Neptunian Planet” outlining the reasoning behind his planet search—supposed anomalies in the orbits of Uranus and Neptune (later proven to be in error). Having founded the Lowell Observatory in 1894 to search for evidence of life on Mars, Lowell purchased an astrograph to capture wide-angle images of the sky and a blink comparator to switch back and forth between two images of the same part of the sky in an effort to find something that moved against the background stars.

Ironically, while Lowell died in 1916 thinking his search failed, Pluto appeared in photographic plates of the sky he took in 1915 but was not recognized and thought to be one of many background stars.

Twenty-four-year-old Clyde Tombaugh, hired by the Lowell Observatory in 1929 to continue the search, used the astrograph to image photographic plates and the blink comparator to compare images of the same parts of the sky taken several days apart. Within a year, he discovered Pluto.

It took until 1988, when Pluto was imaged using CCD cameras, for scientists to discover it has an atmosphere.

Similarly, getting New Horizons to launch was another protracted, long-term effort. Principal Investigator Alan Stern noted that the idea of a Pluto mission was first raised in 1989, after Voyager 2 flew by Neptune. Five separate mission proposals were made and subsequently canceled. But the scientists who advocated a Pluto mission, nicknamed the “Pluto Underground,” refused to quit. When the Johns Hopkins University Applied Physics Laboratory (JHUAPL) was finally awarded the mission, they were given only a few years to build the spacecraft and its instruments to fit the necessary launch window.

“Pluto is the story of perseverance, of not taking no for an answer, of saying, ‘yes I can,” emphasized Lowell Observatory historian Kevin Schindler at the conference. “This is one of the reasons that inspires so many people about Pluto.”

Today, we are in yet another situation that requires perseverance, both in terms of getting a better planet definition that restores Pluto and all dwarf planets to full planethood, and in the effort to return to the Pluto system with an orbiter.

Two days ago, the publication Morning Overview reignited hope by publishing an article titled, “Why Pluto Could Be Reclassified as A Planet Again.” The article cited recent scientific studies that reveal Pluto to share many characteristics with the solar system’s larger planets, including a complex atmosphere, geological activity, and varied surface features, such as mountains, valleys, and plains.

“Pluto is unique in many ways. Its size and composition are comparable to other planets in the solar system, albeit smaller. It has a rocky core surrounded by a mantle of water ice, and its surface is covered in nitrogen ice, with traces of methane and carbon monoxide. This composition is not unlike that of terrestrial planets, further blurring the lines between Pluto and its larger counterparts,” the article noted.

The article goes on to mention the possibility of Pluto having a subsurface ocean and the uniqueness of Pluto-Charon as a binary system, the only one in our solar system.

Acknowledging the efforts by so many, not just scientists, the article credits popular culture for keeping the notion of Pluto as a planet alive for close to two decades.

“Popular culture, through media and educational systems, has maintained Pluto’s image as a planet…Grassroots movements and public interest can significantly influence scientific decision-making, as seen in past scientific debates and reclassifications.”

And there we have it. Our efforts have kept this debate and Pluto’s status as a planet alive in both culture and science. Though it may not always seem that way, our efforts are making a difference.

The article goes on to list the benefits of Pluto being recognized as a planet, which include more scientific research and funding to study Pluto and similar objects as well as renewed searching for hard-to-find planets both in our solar system and others.

“As discussions continue, the potential reclassification of Pluto as a planet remains an intriguing possibility that could reshape our understanding of the Solar System,” the article concludes.

Pluto’s story is one of perseverance, and that continues today. Regardless of how much time has passed since the IAU vote, we today need to call upon that perseverance and stick with the effort to undo the travesty of 2006 and gain a better planet definition. Never give up. Never, never, never give up.

Pluto's Hazes and Charon's Geology: Notes from the July Conference

 

The conference “Progress inUnderstanding the Pluto System: Ten Years Since Flyby” covered a wide range of topics regarding Pluto, Charon, other KBOs, ocean worlds, and more. With apologies for the delay in this entry, I will focus now on two of these topics: Pluto’s atmospheric hazes and Charon’s geology and history.

Launched in late 2021, the James Webb Space Telescope (JWST) observed Pluto’s atmosphere in infrared wavelengths. Other than New Horizons, no instrument has been able to study Pluto’s atmosphere because it is so cold. These hazes, which likely have a high ice content, likely control Pluto’s climate and keep its upper atmosphere cool.

While the spectrum of Pluto’s hazes somewhat resembles the spectrum of the atmosphere of Titan, Saturn’s large moon, Titan’s atmosphere has much less ice than Pluto’s. The sublimation and condensation of ices plays a significant role in Pluto’s atmosphere but not in Titan’s.

New Horizons observed layered hazes covering all of Pluto. While both Pluto and Titan have nitrogen in their atmospheres, Pluto’s also contains carbon monoxide. Given that Pluto is farther from the Sun than Titan, it is understandable that the former’s atmosphere is colder than the latter’s.

Several of New Horizons’ instruments observed Pluto’s atmospheric hazes, which are believed to form through photochemistry of methane and nitrogen. These hazes vary with Pluto’s seasons and during its elliptical solar orbit, as well as with the Sun’s 11-year cycle. When Pluto gets closer to the Sun, Pluto’s volatile ices sublimate and are lifted into its atmosphere.

For Charon, New Horizons’ LORRI, MVIC, and LEISA instruments were used to image the planet and create a mosaic making up 80 percent of its surface. Topographic features were best seen when the Sun was low in Charon’s sky while reflectivity features were best seen when the Sun was high.

Though Charon’s non-encounter hemisphere was imaged in low resolution, topographic features such as massive canyon systems, moated mountains, mottled terrain, and alternating areas of smooth and rocky terrain could still be seen. There are many impact craters but not enough to saturate the surface. Patterns of bright and dark ejecta not seen anywhere else in the solar system are visible on Charon’s surface.

These features suggest Charon has a volatile crust as well as strong layering beneath its surface. All of them indicate a long ago freezing of the planet’s ice shell. This freezing of what was once a subsurface ocean happened very early in the system’s history, before Pluto and Charon became tidally locked to one another.

Charon has about 200 scarps or steep cliffs that are taller than the Grand Canyon on Earth. These might be the largest canyons relative to planet size in the entire solar system.

While Pluto has both young and old surface terrain, Charon’s surface is approximately two billion years old. Large craters on both objects were likely created by ancient impacts of KBOs approximately the size of Arrokoth. Charon’s craters contain a record of impactor populations, which created its large craters. Few small craters have been seen on Charon’s surface. Impactors that hit Charon excavated material from its subsurface.

New Horizons’ instruments showed that water ice is ubiquitous on Charon’s surface. Observations by JWST revealed the presence of carbon dioxide, hydrogen peroxide, and ammonia diluted in water on Charon’s northern hemisphere. Significantly, Jupiter’s moon Europa also has carbon dioxide in its spectrum. Impactors that hit ancient Charon appear to have exposed what had been subsurface carbon dioxide.

What is especially significant is that Charon’s surface appears to have accurately preserved its formation and impact history.

The red spot visible on Charon’s north pole is comprised of tholins, complex organic molecules found in space created by the interaction of ultraviolet sunlight with methane, nitrogen, and water on an object’s surface or in its atmosphere. These tholins originate from methane that escapes Pluto’s atmosphere that is then gravitationally captured by Charon. Only Charon’s nighttime temperatures are cold enough for methane to condense on its surface. Most of this methane is converted to ethane; only ten percent is processed into sticky surface materials.

Like Pluto as well as Titan, Europa, and other solar system bodies, Charon may have once been an ocean world. The freezing of that ocean likely caused expansion of surface features once the planet’s internal heating shut down. Features such as canyons, rifts, and fractures, all seen on Charon, have also been observed on other icy moons that may have subsurface oceans.

There is some evidence Charon may once have experienced cryovolcanism, such as shallow fractures and landslides, which are seen on elsewhere in the solar system on Ceres, Europa, and Uranus’s moon Ariel. Charon’s north appears to be heavily cratered while other areas are composed of smoother cryovolcanic planes.

These factors reveal Charon to have once been one of a growing number of ocean worlds in the solar system. While Charon’s ocean has since frozen, Pluto’s, like those of Europa, Titan, Ceres, Saturn’s moon Enceladus, Jupiter’s moon Ganymede, and Neptune’s moon Triton could still exist in liquid form. While no signs of microbial life have yet been found on any of these worlds, the presence of liquid water and organic compounds raises the possibility that these oceans could harbor such life. This is one of many reasons we need further exploration, especially by instruments that can drill through the ice layers and study the liquid below.

 

 

 

 

 

Pluto and Charon Geophysics and Climate: Notes from the Conference

“Progress in Understanding thePluto System: Ten Years after Flyby” was a focused, informative conference in which scientists spent four-and-a-half days discussing Pluto in detail, comparing it with other, similar solar system bodies, and celebrating the milestone 10^th anniversary of the 2015 New Horizons flyby.

Alan Stern, New Horizons principal investigator, opened the conference by describing its goal as “bringing together everything we’ve learned about the Pluto system since the flyby.”

Because so much ground was covered during the weeklong, conference, it would be impossible to discuss everything in one entry, which is why I plan to write several for this site.

In the first session, “Pluto after Ten Years: A Holistic View,” discussion centered on Pluto’s climate, geological history, atmosphere, and chemistry. A second session focused on the geology and composition of Pluto’s largest moon and binary companion, Charon.

Throughout the conference, Pluto and its system of moons were compared and contrasted with Ceres, Haumea, Eris, Arrokoth, other Trans-Neptunian Objects and small planets, Neptune’s moon Triton, Saturn’s moons Titan and Enceladus, and Jupiter’s moon Europa.

While little is known about Haumea and Eris, every other one of these worlds is either an ocean world or a world suspected of having a subsurface ocean. This class of objects was relatively unknown just decades ago, but today, these worlds are front and center in the search for microbial life in the solar system.

In the lead up to the flyby, some scientists expected Pluto to be revealed as a geologically dead world, like our moon. Instead, many were surprised to find it, in the words of presenter Oliver White, “a geological wonderland at the edge of the solar system.”

Much focus was placed on Sputnik Planitia, the floating glacier that comprises the left side of Pluto’s “heart” feature, and the repository of the planet’s nitrogen ice. We know Sputnik Planitia is geologically young, has nitrogen ice flowing on its surface, and has no craters.

The flow of ice on Sputnik Planitia is similar to processes on Earth, but with nitrogen ice instead of water.

Pluto’s annual cycle is driven by the planet’s high obliquity or tilt toward the plane in which most but not all of the solar system’s planets orbit. Its north-facing slopes all have small deposits of methane ice. Over thousands of Pluto years, its equatorial regions have received less sunlight than its polar regions.

Pluto’s diverse geology, including bladed terrains, dunes, pitted regions, and even likely cryovolcanoes are the result of both endogenic, or internal, processes, and exogenic, or external ones.

The New Horizons team did not even know that Sputnik Planitia was there when the flyby was planned. Since this region controls almost everything that occurs on the planet, the opportunity to image it in high resolution was extremely fortuitous.

Not being a satellite of a giant planet, Pluto experiences no tidal heating. Its biggest source of energy is radioactive decay of rock.

The ancient impact that formed Charon melted ice, fractured terrain, and created Sputnik Planitia.

While the presence of a subsurface ocean on Pluto remains hypothetical, it is supported by a lot of evidence. Presenter James Tuttle Keane noted that a structure like Sputnik Planitia cannot have been created without an ocean.

Computer models are frequently used in studies to simulate conditions on remote objects like Pluto. Keane noted that “New Horizons triggered a wave of new theoretical models reshaping our understanding of Pluto and worlds beyond.”

Its axial tilt and eccentric orbit give Pluto extreme summers and winters. Its lower latitudes get at least some sunlight every day while its higher latitudes can go for long durations with no sunlight at all. These differing climates produce a variety of landscapes on Pluto’s surface.

But sunlight is not the only energy source on Pluto, which obtains a higher fraction of its energy from internal sources than the Earth does.

New Horizons found that Pluto’s atmosphere is escaping into space at a much lower rate than expected.

Much discussion centered on early migration of solar system planets. Neptune is believed to have formed closer to the Sun only to subsequently migrate outward. Now located at 39 AU (astronomical units, with one AU equal to 93 million miles or the average Earth-Sun distance), Pluto may have formed at 25 AU and then been pushed outward by Neptune.

Data obtained when various small planets occulted (passed in front of) a star indicate that Pluto, Charon, Haumea, Triton, and Quaoar all have similar densities.

“These objects are not iceballs,” emphasized presenter Bill McKinnon, a point that supports their classification as small planets. This is significant in light of the fact that the media often erroneously lump dwarf planets and tiny Kuiper Belt Objects (KBOs) in one broad category.

And KBOs, even those too small to be round, are not just giant comets—they are far more active than comets are.

Pluto’s atmosphere is similar to that of Saturn’s moon Titan, which itself is sometimes viewed as an analogue of early Earth. Its surface ices are methane, nitrogen, and carbon monoxide. Photochemical organic aerosols in Pluto’s atmosphere create its layered hazes, which extend to an altitude of more than 217 miles.

 Both Pluto and Triton, Neptune’s large moon that is believed to have once orbited the Sun on its own only to be captured by Neptune, look very different from comets. Rather than being frozen relics, both have interior energy sources. Because Triton orbits Neptune, a giant planet, it experiences far more tidal heating than Pluto.

Pluto and Triton have low levels of carbon monoxide in their surface ices. Data collected by the James Webb Space Telescope (JWST) show Eris and Makemake also lack surface carbon monoxide. As neither orbit a giant planet, their surfaces may be more like that of Pluto than that of Triton.

Since Triton is believed to have originated in the Kuiper Belt, all of this is evidence that supports classing these objects as a new subclass of planets, similar to one another but different from comets.

The distribution of ices on Pluto’s surface varies with its terrains. Nitrogen frost is found at the bottom of craters. Bright and dark regions on Pluto have different ice compositions.

Data collected by New Horizons’ MVIC and LEISA instruments was used in 2023 to create spectral maps of Sputnik Planitia, Cthulhu Macula, and Lowell Regio, regions on Pluto’s surface.

A global topography map of Pluto created in 2018 used data from New Horizons and stellar occultations to depict the distribution of volatiles, chemical elements and compounds that can be easily vaporized.

Three regions on Pluto—Kiladze, Viking Terra, and Virgil Fossae—could be cryovolcanoes. These resemble structures on Mars known to be cryogenic caldera, or depressions formed by cryovolcanism.

While Pluto’s topography is current, Charon’s is ancient. Charon may have experienced tectonics, processes that shape and create a planet’s crust, early in its history. While it may have once had a subsurface ocean, that has long since frozen solid.

Progress in Understanding the Pluto System: Ten Years After Flyby

 

It is almost impossible to believe, but tomorrow marks the 10^th anniversary of New Horizons’ historic Pluto flyby. To commemorate the anniversary and reflect on what has been learned about Pluto in the decade that has passed, the Universities Space Research Association’s (USRA) Lunar and Planetary Institute (LPI) is holding a weeklong conference titled “Progress in Understanding the Pluto System: Ten Years Since Flyby” from July 14-18 at the Johns Hopkins University Applied Physics Laboratory (JHUAPL), mission headquarters, in Laurel, Maryland.

The four-and-a-half-day conference offers an option to attend virtually, which I will be doing this week, and reporting here on the talks. Topics to be addressed include Pluto’s volatile ices, its geology and geophysics, its climate history, its atmosphere, Charon’s geology and craters; the comparative planetology of dwarf planets and Kuiper Belt Objects; history of the New Horizons mission; future exploration of Pluto and the Kuiper Belt; the origin of Pluto and its moons, and more.

On the afternoon of Thursday, July 17, presentations will address possible return missions to Pluto, including Persephone, a proposed Pluto orbiter and Kuiper Belt explorer, and the Gold Standard Mission, also a Pluto orbiter proposal and extended Kuiper Belt exploration mission.

While these are currently only in the concept stages, they matter because the New Horizons flyby raised more questions than answers, leading scientists to recognize the need for a follow up orbiter mission.

A Pluto day, one rotation of the planet on its axis, takes 6.4 Earth days. As a flyby mission, New Horizons did not have the time to study Pluto for a full rotation, as the spacecraft could not brake and slow down to observe the planet. Therefore, only one hemisphere of Pluto was imaged and studied in high resolution. The other hemisphere was imaged only on approach in low resolution, meaning less is known about it. An orbiter would reveal the secrets of that hemisphere as well as provide additional data about the side of Pluto that was explored in high resolution.

While the current political climate may not be conducive to spending money on new planetary missions, this could very well change with a different administration, so it is important to develop and study possible plans for a follow up mission.

Here, you can find a program of the conference talks along with links to the abstracts of those talks.

Oppose cuts to NASA missions: Call your representatives and senators now

 

                                           This image shows NASA missions that are cancelled in this bill

The proposed US budget reconciliation bill, which many of us refer to as the Big Ugly Bill, is a huge disaster for NASA and its space programs, including New Horizons, and anyone who values our space program must do everything in our power to make sure it does not pass.

Well known for its disastrous proposed cuts to Medicaid, , SNAP, social safety net programs, and environmental protection, this bill proposes huge cuts to NASA, including cancellation of the New Horizons mission, the Mars Sample Return mission, Juno, OSIRIS-Rex, MAVEN, various Earth science projects, the Chandra X-ray Observatory, the Nancy Grace Roman Space Telescope, the Lunar Gateway program, the Space Launch System, the Orion spacecraft after the Artemis 3 mission, and many others, for a total reduction of agency funding by 25%.

No reasons are given for the proposed termination of these programs, but presumably, the cuts would be done to fund yet another tax break for the wealthy and large corporations—the last thing this country needs.

Personally, I am a Democrat and a progressive, though I have tried to keep these views out of this blog and focus on Pluto’s planethood, planetary science, and our space program.

However, one does not need to be a Democrat or progressive to recognize how disastrous these cuts to NASA would be for our country and for science.

It is fair to say that the US space program has been a key player in American greatness since the 1960s. To this day, the US is the only country that has ever landed astronauts on the Moon, and it is the only country to have robotically explored all of the solar system’s planets, with the exception of newly-discovered remote dwarf planets such as Haumea, Makemake, Eris, Sedna, Orcus, etc.

In 2019, New Horizons conducted the most distant flyby of any solar system object when it visited KBO Arrokoth, located four billion miles (6.4 billion km) from Earth. Mission team members are still searching for a third, even more distant KBO flyby target.

Today, New Horizons is studying the solar wind, studying the Kuiper Belt far beyond Pluto, and even contributing to heliophysics, and the study of structures and processes in the Milky Way galaxy.

Every one of the NASA missions targeted for cancellation has contributed to our understanding of the origins and formation of the solar system, the study of astrophysics and cosmology, and the workings of Earth’s climate.

These missions have made the US a worldwide leader in science and have even led innovations in technology and robotics with far ranging implications, including new ways of assisting people with disabilities.

It is inconceivable that an administration whose stated goal is to make America “great” would propose to cancel so much of exactly that which makes us great.

Needless to say, cancellation of these missions will result in many scientists losing their jobs and thereby will increase our country’s unemployment rate. We are already experiencing a “brain drain” of scientists in other fields leaving the country due to other cuts being enacted to government programs in science, technology, and health.

I urge everyone, regardless of party affiliation, to contact your Senators and Congress members and urge them to vote against this bill and against these cuts. They amount to a giant step backwards, the exact opposite of the direction toward which we should be moving. If anything, NASA’s budget should be increased to the levels it was during the Apollo missions.

To contact your U.S. Senators and Representatives, you can visit the official websites of the House of Representatives and the U.S. Senate (.gov). You can find their contact information, including website links and online contact forms, by searching for your representatives based on your zip code or by browsing the directory of members.

This bill may be voted on within the next few days, so please call now to save these crucial missions and our space program!

Scientists Make Groundbreaking Discovery about Pluto's Formation

 This sounds similar to the formation theory for Arrokoth.

https://www.msn.com/en-us/news/technology/scientists-make-groundbreaking-discovery-about-pluto-s-formation/ar-AA1Em10J?ocid=nl_article_link

Pluto at 95

 

Happy International Pluto Day! Ninety-five years ago today, on February 18, 1930, 24-year-old Clyde Tombaugh discovered Planet Pluto while blinking between photographic plates of the sky taken on two separate nights in January of that year.

The goal was to find anything that moved against the background stars between nights. That object would not be a star but a planet within our solar system.

The announcement of Pluto’s discovery was not made until a month later, on March 13, 1930 by the Lowell Observatory, which chose this date because it was the birthday of its late founder Percival Lowell as well as the anniversary of the discovery of Uranus in 1781.

Incredibly, Tombaugh was not even credited in initial announcements of the discovery. He was described as a “junior astronomer” and not named, as the observatory wanted to focus the credit on Percival Lowell, who had predicted the existence of a planet beyond Neptune but had not actually found it.

Ironically, given that Lowell died despairing about never having discovered the planet, Pluto does appear on what are called “precovery” images he took around 1905 and 1906. It is not unusual for scientists to search earlier images after the discovery of a celestial object to determine whether that object appeared in a photo but remained unrecognized.

That was the case with Lowell and Pluto. He had photographed Pluto, but he didn’t recognize it for what it was, likely because he was looking for a giant planet like Uranus or Neptune rather than a small one, which Pluto turned out to be.

Celebrated annually at the Lowell Observatory to this day with an I Heart Pluto festival, Pluto’s discovery remains in many ways a triumph of underdogs. Tombaugh had only a high school diploma when he made the discovery. While searching for the planet, he was told by a professional astronomer that he was wasting his time, that if there were any more planets to be found, they would already have been found.

When Lowell Observatory director Vesto Slipher published an article about the discovery in Science News-Letter, he credited Lowell without even mentioning Tombaugh. Similarly, in the same publication, Harvard astronomer Harlow Shapley and Yale astronomer Frank Schlesinger wrote, “to Professor Lowell…belongs the credit.”

A certain elitism among astronomers of the time led them to have trouble accepting that a “kid” without an advanced degree had discovered a planet. Citizen science was not yet a “thing,” and the notion that an ordinary person could make the type of discovery for which those with PhDs worked hard for many years appeared to make those scholars uncomfortable.

After falling into obscurity for decades as the planet the least was known about, Pluto began to regain popularity during the 1960s and 1970s. Its largest moon, Charon, really a binary partner, was found in 1978.

Tombaugh himself described feeling like an outsider, someone who did not quite measure up to others in his field. This is evident from his sense of genuine surprise at his burgeoning popularity following the 50th anniversary celebrations of Pluto’s discovery, in 1980.  Biographer David Levy quotes Tombaugh’s ironic reaction. “I misjudged the attitude of astronomers. I thought I was a nobody. I thought they had contempt for me”

For almost a century, Pluto and its discoverer have shared this underdog quality, from some, a sense that they weren’t good enough and didn’t measure up, but from others, the sense of being a folk hero and a rock star.  Both were seriously underestimated—Tombaugh as a professional astronomer and Pluto as a planet.

Pluto may be smaller than most solar system planets and have an eccentric orbit, but those things do not preclude it from being a planet. They just make it a different type of planet. In the last 30 years, exoplanets have been found with orbits around their stars that are far more eccentric than Pluto’s path around the Sun. Some of these exoplanets are giant, Jupiter-like worlds.

New Horizons surprised scientists and ordinary people worldwide, who had expected to see a dead world but instead were treated to images of one that is geologically active and has some planetary processes seen elsewhere in the solar system only on Earth and Mars.

Yet even now, misinformation about Pluto is rampant. An article about the I Heart Pluto celebration stated that Pluto’s “reclassification” was done because objects larger than Pluto were discovered in the outer solar system. This is not true and is based on information that was proven wrong close to 15 years ago.

Eris was initially thought to be larger than Pluto, but a team of astronomers led by Bruno Sicardy observed it occult (pass in front of) a star in 2010 and found Eris to be marginally smaller than Pluto yet slightly more massive. It is disappointing that so many years later, the initial error about Eris being larger is still being spread in the mainstream media.

With time, Tombaugh has been recognized and fully credited for his discovery. Similarly, as time passes, I believe Pluto will be recognized for and credited as the planet it is. It may be different from the solar system’s four terrestrials and four jovians, but it is far from the only planet of its kind. And it is only a matter of time before similar small planets are discovered orbiting other stars.

Meanwhile, the same persistence and perseverance that led to Pluto’s discovery will motivate those of us who fight for its rightful recognition as a planet. Dwarf planets are planets too!

I Heart Pluto Festival at Lowell Observatory This Weekend

 

Lowell Observatory’s annual I Heart Pluto festival is back, celebrating the 95^th anniversary of Pluto’s discovery on February 18, 1930.

This year’s celebration, held in Flagstaff, Arizona, features a Pluto Pub Crawl with Pluto-themed drinks and talks with Lowell astronomers; various science talks including a keynote Night of Discovery featuring Alan Stern, David Levy, and Adam Nimoy, son of Star Trek actor Leonard Nimoy; various festival activities, and a children’s choir performance of “Ode to Pluto,” the song by Mark Burrows that I sing at my annual birthday party.

There will even be a “Shakespeare on Pluto” performance, a comedy with music celebrating both Shakespeare and space exploration.

For more on these events, which take place tonight and this weekend, visit Lowell’s I Heart Pluto page.

Even if you can’t make it to Flagstaff, this is the time to celebrate Pluto’s discovery 95 years ago and learn more about this small but amazing planet.

I hope some of the talks will be recorded and put online and will keep everyone informed if and when this happens.