New Horizons Should Remain a Planetary Mission

 

A little-known proposal is threatening the future of NASA’s New Horizons mission, and for reasons unknown, the space press has not reported on this development whatsoever.

This needs to change, as the public has the right to know that one of this country’s most successful planetary missions is in danger of being shut down before its time.

Launched in 2006, New Horizons has captured breathtaking images of Pluto and its large moon Charon, as well as a Kuiper Belt Object (KBO) one billion miles beyond it.

From the beginning, New Horizons has been a planetary mission. Its exploration of not just Pluto but primitive KBOs that have remained unchanged since the solar system’s earliest days continues to reveal new insights into the solar system’s formation and evolution.

Now, New Horizons as a planetary mission is facing premature cancellation. For no clear budgetary or scientific reason, NASA’s Science Mission Directorate is considering ending it as a planetary mission and transferring control of it from the agency’s planetary science division to its heliophysics division.

Incredibly, this would remove the current New Horizons team, many of whom have dedicated decades to seeing it through from an idea to launch to Pluto and beyond. Instead, it would put the spacecraft under the control of a new heliophysics team.

When a similar move was done with the Voyagers once they ran out of planets to visit, the mission’s leadership and most of its team was allowed to remain in control. It makes little sense to remove New Horizons from the loyal, dedicated group who fought for it every step of the way and are now guiding it through the uncharted territory of the Kuiper Belt.

Such a move is nothing less than a slap in the face to a team that has poured their minds and hearts into one of NASA’s most successful planetary missions and still have so much more to give.

Eventually, when it leaves the Kuiper Belt, New Horizons will concentrate solely on the heliophysics of the outer solar system. But for now, it still has sufficient fuel to continue studying the Kuiper Belt for another five years. It is the only vehicle in place to conduct in situ study of this region. Arbitrarily ending the planetary mission half a decade early wastes a unique opportunity that neither NASA nor any other space agency is likely to have for decades.

Small KBOs like Arrokoth, which New Horizons flew by in 2019, contain the building blocks of the solar system. The New Horizons team has spent the last few years using very large ground-based telescopes to search for a third flyby target, for which the spacecraft has roughly as much fuel as for the Arrokoth flyby.

What sense does it make to throw away the chance to observe yet another KBO up close as well as many others from a distance?

Currently, no other missions to the Kuiper Belt, and none are even being planned. New Horizons is literally our only chance to explore this region of the solar system in situ for decades.

This proposal is not about money. The move would not save any money, replacing one team with another. Neither does it make scientific sense. It is a senseless step that wastes precious resources for no benefit.

New Horizons has had multiple scientific successes because of the hard work, dedication, and passion of its team. We should be rewarding these scientists and engineers, not throwing them away and forfeiting the chance to study this remote, fascinating region of the solar system for another five years.

Why hasn’t the space press reported on this senseless proposal? The public, who fund NASA, deserve to know that the agency is on the verge of making a wasteful, unnecessary move.

New Horizons thrilled children and adults around the world when it revealed the beauty and complexity of Pluto. Today, the public deserves to know that this mission faces premature termination for literally no reason. Space journalists around the world need to tell this story while there is still a chance of preventing this destructive move.

Hear Ye, Hear Ye! Carolyn Porco and Scott Tremaine are Wrong about Pluto!

In a Facebook announcement dated February 14, 2023, planetary scientist Carolyn Porco takes on the role of planetary town crier, stating, “Hear Ye, Hear Ye! Scott Tremaine, renowned celestial dynamicist & a founder (along w/ my thesis advisor Peter Goldreich) of the field of planetary rings, has written a textbook on The Dynamics of Planetary Systems. At my request of some time ago, he included in his book a discussion of the definition of a planet...And what did he find? Pluto is NOT a planet !! Reason has prevailed. Rejoice!

Porco is admittedly an accomplished scientist best known for her work on NASA’s Cassini mission to Saturn. But in this case, she is wrong.

Reason does NOT prevail when a person with an agenda specifically requests that a fellow scientist push that agenda in his book while refusing to acknowledge the ongoing debate and both sides in that debate.

Porco’s position on the planet definition issue is actually more extreme than that of the IAU. She opposes the use of the term dwarf planet because she claims Pluto and Ceres are both asteroids! She states in the comments, “Actually, I don't ever use, and won't, the name 'dwarf planet'. It's inconsistent. How can something be a dwarf member of a category it doesn't belong to?”

Regardless of their own position on this issue, most scientists acknowledge the ongoing debate between dynamicists and geophysicists over the question of defining a planet. Most show respect for the opposing position even if they don’t agree with it.

In my writings and public presentations, I always make the effort to present both views. While I am clear on the view I hold, I believe it would be a disservice to readers and/or audience members to pretend my view is the only one and that all others have been discredited when this is not the case. I would rather members of the public hear both sides of this issue and then make up their own minds than feed them my viewpoint alone.

Porco goes on in subsequent comments to denigrate the geophysical planet definition by claiming roundness means nothing, adding, that the term dwarf planet “actually has no information in it besides 'sort of roundish'. On the other hand, ‘Pluto is a large Kuiper Belt Object’ tells you composition, location, relative size, approximate level of solar illumination, etc. Far more useful.”

To her, there is apparently no difference between tiny, shapeless asteroids and KBOs and objects large enough and massive enough to be rounded by their own gravity, in spite of the fact that the latter have complex processes not seen on asteroids and in some cases, seen elsewhere in the solar system only on Earth and Mars.

Just calling Pluto a large Kuiper Belt Object tells us nothing about its structure, its geology, its atmosphere, the interaction between its atmosphere and surface, its many varied terrains, its cryovolcanoes, its likely subsurface ocean, and its interactions with companion Charon as the solar system’s only binary planet system.

Pluto actually has far more in common with some of the larger, spherical moons in the solar system, considered by many planetary scientists to be secondary or satellite planets, than it does with tiny, shapeless Kuiper Belt Objects like Arrokoth. Today, planets such as Ceres; Jupiter’s moons Europa, Callisto, and Ganymede; Saturn’s moons Enceladus and Titan; Neptune’s moon Triton, and Pluto are the solar system’s top contenders for hosting microbial life due to the growing evidence that they harbor subsurface oceans.

Porco insists that gravitational dominance alone determines what is a planet without ever addressing the fact that this dominance depends on location and can lead to the same object being considered a planet in one location and not a planet in another one. If Earth were in Pluto’s location, it would not gravitationally dominate or clear that orbit.

Furthermore, she states, “But Mercury, Venus, Earth and Mars dominate their orbital corridors. If they hadn't, you wouldn't see them, you'd see a cloud of debris.

Does Mercury actually dominate its orbit, or does the Sun clear out debris there? The answer is unclear. Furthermore, there is no cloud of debris around Pluto. If there were, New Horizons would have had no trouble finding a second and even a third flyby target. The reality is the Kuiper Belt is vast, and most KBOs are nowhere near Pluto but much further out and very scattered.

She goes on to say, “'Round' is a perfectly useless criterion. It doesn't work for those distant bodies for which we don't, and won't for a very long time to come, if at all, have shape information for. So it fails as a metric for categorization...I mention ‘spherical’ but merely because it’s a side effect of (or proxy for) planetary properties and processes I am interested in with categorization in mind. E.g: a degree of planetary differentiation.”

But another commenter points out that gravitational dominance is much more difficult to detect at great distances than is roundness, and that time and the technological advancements that go with it will eventually answer these questions for distant objects, both in our solar system and others.

Additionally, planetary differentiation is very much related to roundness, as she admits in the sentence I bolded above. Active geology begins happening when objects reach the threshold of being rounded by their own gravity. Categorizing Ceres and Pluto as asteroids is bad science because it blurs the distinction between complex objects shaped by their own gravity and tiny ones that are often little more than rubble piles, held together only by their chemical bonds.

One commenter even repeats the false claim that Mike Brown discovered dwarf planets larger than Pluto despite the fact that no such dwarf planets have been found. Eris was initially thought to be larger than Pluto, but in November 2010, a team of astronomers led by Bruno Sicardy observed it occult a star and found it to be marginally smaller than Pluto though slightly more massive.

The persistence of this misconception after more than a decade is an example of why the IAU definition has harmed science by widely spreading confusion and incorrect information.

Unfortunately, the tone of the discussion in the comments takes a turn for the worse when Porco resorts to personal attacks against New Horizons Principal Investigator Alan Stern and other supporters of the geophysical planet definition, demeaning them by calling them “Pluto fanatics.”

Here are some examples of her inappropriate personal attacks:

“The Pluto fanatics were desperate to get a Pluto mission, and it was deemed of vital importance to maintain Pluto as a planet, so they would have more justification. They were practicing politics, not science.”

This is blatantly false. New Horizons was already approved and had already launched when the IAU vote took place. Most New Horizons scientists view Pluto as a planet because they favor the geophysical definition over the dynamical one. It is a purely scientific disagreement.

As New Horizons planetary scientist Cathy Olkin noted, "I naturally refer to Pluto as a planet because that seems like the right moniker. It has an atmosphere; it has interesting geology; it orbits the sun; it has moons. 'Planet' just seems right to me."

Porco went on to comment, “Stern has admitted he wanted Pluto to be a planet because he was afraid New Horizons wouldn’t be chosen if it wasn’t. He DOES appeal to emotions. You want to compare our respective domains of expertise? Stern did a mission to Pluto. I ran an experiment and published papers that required knowledge on my part in atmospheric meteorology, the kinematics and dynamics of planetary rings including faint rings of tiny micron-sized particles, the geology, geophysics and geodesy of planetary satellites, the tidal interactions between planetary bodies, the geysering eruptions of Enceladus, and a lot more. So, a body like Pluto is NOT outside my field.”

Again, her first statement is false. And while Porco did accomplish everything she states, Stern has also published numerous papers on many of these same subjects and is the world’s leading Pluto scholar. And his advocacy and leadership of the New Horizons mission essentially unveiled Pluto to the entire world.

Porco should feel secure enough in her own accomplishments to not belittle another scientist who clearly made extensive contributions to planetary science just because he disagrees with her on planet definition.

In one remark, she responded to a commenter by saying, “You are clearly an ignoramus and should keep your mouth closed.”

She even goes as far as comparing opponents of the IAU definition to climate deniers!

Ad hominem, or personal attacks, are a sign that someone is losing the debate.

Significantly, Porco blocks me on Twitter, and I could not comment on her Facebook page because it only allows those she permits to comment.

But I will not keep my mouth closed. I will not be silenced, and neither will advocates of the geophysical planet definition.

If someone has to resort to censorship to force their view on the world and disallow any comments that disagree with their view, they are NOT causing reason to prevail. They are enforcing tyranny. And that is anything but a reason to “rejoice.”

New Horizons: NASA’s Mission to Pluto and the Kuiper Belt, by Alice Bowman: I Heart Pluto Festival 2023

The Future of New Horizons: An Interview with Dr. Alan Stern | I Heart Pluto Festival 2023

Planet Pluto Discovered 93 Years Ago Today, February 18, 1930

 

On February 18, 1930, exactly 93 years ago today, 24-year-old Clyde Tombaugh discovered Planet Pluto while blinking between two photographic plates of the same part of the sky taken six days apart at the Lowell Observatory in Flagstaff, Arizona.

He found a tiny dot that moved against the background stars from one plate to the next and thus succeeded just over a year after arriving at Lowell Observatory to take up the search for a new outer solar system planet, begun many years earlier by observatory founder Percival Lowell.

Now close to 130 years old, the Lowell Observatory is today holding its annual “I Heart Pluto” celebration to commemorate the discovery. The 13-inch Lawrence Lowell telescope Tombaugh used to take the photographic plates, recently restored, still sits within its original dome and is viewed by visitors every day.

Discoveries are not always well understood at the time they are made. In Pluto’s case, the new planet was too small to be resolved into a disk, leading some scientists to speculate that it might be a moon of a not-yet discovered larger parent planet.

Eventually, telescopes became powerful enough to resolve Pluto into a disk, but even Hubble images taken during the 1990s were fuzzy. The real revelation of Pluto in all its glory happened in 2015, when the New Horizons spacecraft flew by that world, imaged its varied terrains, and returned data that is still being studied and analyzed today.

Tombaugh and his fellow astronomers in 1930 had no way of knowing that they had found the first of many small planets in what is now known as the solar system’s third zone. They certainly had no inkling that the newly discovered world was one of many solar system objects that has a subsurface ocean possibly capable of hosting microbial life.

With the recent renewed interest in UFOs, it is important to remember that as of today, we have not even determined whether any other place in our own solar system harbors life. What we have discovered is that small planets Pluto and Ceres, as well as various moons of the gas and ice giants, likely have oceans beneath their surfaces that could potentially host microbes. Among that growing list of worlds are Jupiter’s moons Europa, Ganymede, and Callisto; Saturn’s moons Enceladus, Titan, and possibly even Mimas; Neptune’s moon Triton, and possibly Pluto’s binary companion Charon.

Distant planets like Eris and Sedna could also potentially host such oceans, but we won’t know until we send probes to study them up close.

On February 18, 1930, Clyde Tombaugh had no way of knowing that he had not only unlocked a third zone of the solar system, but also discovered a new class of ocean worlds that could be the prime locations for life taking hold beyond the Earth.

While it is clear that any extraterrestrial life in our solar system is limited to microbes, finding evidence of such life on any world would be one of the most significant scientific discoveries in history, as it would confirm life got started on worlds other than Earth.

Tombaugh also could not have known that the world he discovered was not a dead rock, but a geologically active planet that appears to have an internal heat source. No one expected something like this so far from the Sun. Today, the discovery of Pluto’s complexity and activity raises the possibility that other, even more distant worlds, could also be active planets.

Our technology is not yet at the level of being able to discover Pluto-sized planets in other solar systems, but the ability to do so is likely just a matter of time. While his search was for a gas giant planet, Tombaugh discovered the first in a new subclass of planets, the dwarf or small planets, largely but not solely present in the outer solar system. It is reasonable to hypothesize that other solar systems could also have regions like this, with scattered small planets that might be hiding subsurface oceans.

Some in the astronomy community did not give Tombaugh sufficient credit for his discovery back in 1930. His name was not even mentioned in Lowell Observatory’s press release announcing the discovery. Some astronomers of the day even looked down on him because he was a 24-year-old with just a high school education, not an astronomy PhD.

Yet even here, Tombaugh set a new trend though it would not become a “thing” until many decades later. This trend is that of astronomical and planetary discoveries being made by ordinary citizens, amateur astronomers, and even kids, who don’t have PhDs, but are passionate about the universe. Internet and telescope technology have opened the discovery process to interested citizens around the world, who have discovered exoplanets, brown dwarfs, supernovae, etc.

In so many ways, Tombaugh was far ahead of his time. This is also true of his staunch support of Pluto’s planethood. Doubts about that began not in 2005 but in 1930, soon after its discovery. Yet Tombaugh never wavered in his position even though he did not live to see the New Horizons flyby. Today, we know that Pluto is actually part of a binary system with Charon, meaning it is not one but two planets! The system’s four smaller moons orbit not Pluto itself but the center of gravity between Pluto and Charon.

This is a day to celebrate Planet Pluto and its opening of new frontiers in solar system and planetary studies. I personally wish I could be at Lowell Observatory’s I Heart Pluto celebration and hope to to be there for the centennial in 2030.

This year’s celebration will conclude with two talks that will be livestreamed online. The first, “The Future of New Horizons,” will be presented by Alan Stern on Sunday, February 19, at 7 PM Mountain Standard Time, which is 9 PM Eastern time. The second, “New Horizons: NASA’s Mission to Pluto and the Kuiper Belt,” by New Horizons engineer and mission operations manager Alice Bowman, will be presented on Monday, February 20, at 7 PM Mountain time/9 pm Eastern time.

Happy Discovery Day, Planet Pluto!

I Heart Pluto Festival Returns to Lowell Observatory

It is almost the 93rd anniversary of Pluto's discovery on February 18, 1930, and that can mean only one thing--Lowell Observatory's annual I Heart Pluto celebration is back! Find out more here! While celebrations on February 18 will be in person at Lowell Observatory, there will be two talks livestreamed online on YouTube, one on February 19 and the other on February 20, as follows:

Sunday, Feb. 19, 7 pm: The Future of New Horizons: An Interview with Dr. Alan Stern

Monday, Feb. 20, 7 pm: The Latest News from Pluto and Arrokoth, with Alice Bowman, Engineer/New Horizons Mission Operations Manager, Johns Hopkins University Applied Physics Laboratory

Winter Solstice 2022

 

We have once again reached that noteworthy milestone—in the Northern Hemisphere, it is the Winter Solstice, the shortest day and longest night, the turning point of the year when darkness stops advancing, and the Sun appears to stand still in the sky before reversing course.

It’s been quite a year for space exploration. The James Webb Space Telescope successfully launched just about a year ago in spite of endless delays and repeatedly going over budget. It performed flawlessly in unfurling its sunshield and mirror, reaching its Lagrange Point position, and returning stunning images that open a new era of exploration for astrophysics, planetary science, and cosmology.

Another long delayed project, our return to the Moon, also finally launched this year. Artemis I sent back beautiful close up photos of both Earth and Moon, reminiscent of the famous Apollo 8 image captured at this time of year back in 1968—a picture that had a profound impact on many and played a key role in launching the environmental movement.

While 2022 has certainly had its share of challenges, it brought to fruition projects some doubted would ever launch, revealing that late does not mean never and reminding us that if something really matters, giving up should never be an option.

People who have had the good fortune to travel to space note it brings a life-changing perspective. From there, no borders are visible, just one fragile planet, now home to 8 billion people and numerous other life forms.

We all, not just world leaders, need that change in perspective because the problems our home planet faces cannot be addressed by just one group of people or one country. The only way we have any hope to stabilize our climate, mitigate the worst effects of climate change, and clean up our air, land, and water, is to come together as one people on one planet.

Too often, people look at the year-end holidays in ways that divide us, at a time when, more than ever, we need to unite to preserve our planet’s habitability for future generations—so we can one day explore the solar system and eventually the stars.

This day, at its core, is about hope. It is about light and life, known by the Romans as the Birthday of the Unconquerable Sun. This makes it an ideal time to treasure the gift of our planet and affirm the amazing things we can accomplish when we come together for a common goal—like launching JWST and sending astronauts to the Moon.

If we can do those things, we can save our planet for future generations. May the year that starts with the return of the light inspire us all to come together and choose a future of light and life.

“We are the power in everyone

We are the dance of the Moon and Sun

We are the hope that cannot hide

We are the turning of the tide!”