Saturday, March 17, 2018

Debunking an Urban Legend of Asteroidal Proportions - Philip Metzger

Planetary scientist and physicist Philip Metzger has written a very informative blog entry debunking misconceptions about the alleged past demotion of asteroids from planets to non-planets. Below is the link to his entry, which summarizes a paper he cowrote with fellow planetary scientists Mark Sykes, Alan Stern, and Kirby Runyon for publication in a science journal and for a public presentation, "Planetary Taxonomy: The Geophysical Planet Definition," which will be presented tomorrow, Sunday, March 18, 2018, at the Lunar and Planetary Sciences Conference 2018.

Debunking an Urban Legend of Asteroidal Proportions - Philip Metzger:

A pre-print of the whole journal article is available for download here:

Just how unscientific has the IAU been about planet definition over the years? Metzger tells this shocking story:

"I mentioned above about authorities 'imposing decisions on individual scientists.' Does that really happen? Well, the IAU tried to make it happen. A colleague who is on the editorial board of one of the major planetary science journals told me that the IAU wrote to the editors and asked them to deny publication to any manuscript that doesn’t bend the knee to accept the IAU’s definitions. My colleague says the editors decided to reject the request. Thankfully so! Scientific freedom lives to fight another day."

Saturday, March 10, 2018

Today: Pluto Discovery Telescope Grand Renovation at Lowell Observatory

Today, the Lowell Observatory in Flagstaff, Arizona, where Pluto was discovered 88 years ago, is holding a Grand Reopening celebration for the 90-year-old Pluto Discovery Telescope, which just completed a year of renovation.

Sunday, February 18, 2018

Pluto at 88: The Debate Continues

Pluto, known to humanity just since 1930, has been a solar system planet for four billion years but was discovered as one 88 years ago today, on February 18, 1930, by astronomer and planetary scientist Clyde Tombaugh at the Lowell Observatory in Flagstaff, Arizona.

An article published yesterday in TheWashington Post reports that six-year-old Cara Lucy O’Connor of Ireland, with the help of her teacher, wrote a letter to NASA asking the agency to reinstate Pluto as a planet. Based on Cara’s statements in the article, it is fair to say she knows more about the solar system than most adults and maybe even more than the 333 non-planetary scientists at the 2006 IAU General Assembly who voted for the resolution that says dwarf planets are not planets at all.

Especially interesting are the comments written in response to the article, many of which are replete with the same errors and misconceptions that have now been repeated for 11-and-a-half years.

While Cara cannot be expected to know this, the controversial vote to demote Pluto was not made by NASA but by four percent of the IAU. Contrary to some people’s comments, NASA does not formally accept or reject the IAU decision. Instead, the agency leaves that decision up to its individual scientists. This is why some NASA websites continue to include Pluto as a planet while others do not.

Most scientists on NASA’s New Horizons mission do consider Pluto and all dwarf planets to be a subclass of planets. Since this group actually flew a probe to Pluto, the last thing NASA is likely to do is tell them they are wrong. Thanks to the mission team, humanity has seen Pluto up close and has learned more about this geologically active world than was known prior to the 2015 flyby during the 85 years since its discovery.

Among the misconceptions repeated in the comments are that there are Kuiper Belt Objects out there that are larger than Pluto (there are none known though even if there were, that would not preclude all of them from being considered planets), that the “experts” of the world made a scientific decision that has broad consensus among scientists ( they didn’t, and it doesn’t), that being in a belt of objects is the primary determinant of what an object is (this completely ignores an object’s intrinsic properties), that the Lambda factor in Alan Stern and Hal Levison’s 2000 paper precludes dwarf planets from being planets (it doesn’t), that Stern alone has a personal interest in Pluto being classed as a planet (he is far from alone; most planetary scientists take this same position), and that the number of planets has to be kept small because people can remember only at most ten numbers in a sequence (this is erroneously based on the notion that memorizing a list of names is the way to teach kids about the solar system).

In many ways, the IAU vote is a lot like climate change science funded by oil companies and other industries with special interests in a particular outcome. Those working on these studies know where their money is coming from and set out to “prove” a foregone conclusion in favor of their funders. So, too, the four percent of the IAU who voted in 2006 had a prior agenda of excluding Pluto from the list of planets. They then crafted a definition that met the conclusion they had already decided on. That is where the orbit clearing “requirement” came in. What we have here is something that looks like science but is not the real thing.

Some writers mock Cara with condescending remarks about how scientists should not give in to the “whim” of a child. Others frighteningly buy into the notion that the IAU is the body of experts who have been “empowered” by the world to make such decisions.

Nobody has so “empowered” the IAU. The organization appointed itself to do this, in spite of the fact that its true mission is to “safeguard the science of astronomy.” As I have noted many times, most of the 424 IAU members who voted in 2006 were not planetary scientists but other types of astronomers—hardly the ones who should be telling the world what is and is not a planet. IAU definitions are intended for internal organizational use, not meant to be imposed on the entire world. And no one raises the issue that science is not dictated by decree of “authority.” Galileo addressed this notion 400 years ago, yet it seems some have not learned the lessons of his experience. Like today’s planetary scientists, he observed phenomena that contradicted the decrees of the “authorities” of his day. He saw that Jupiter has moons, that Venus has phases, that the Moon has craters and diverse features, that the Milky Way is made up of numerous individual stars—and was not afraid to publicly present his findings in contradiction to those “authorities.”

Other comments include the old staples about how “Pluto doesn’t care” what it is called, a need to accept change based on new discoveries, claims that Pluto is fundamentally different from the larger planets, and even political statements regarding Barack Obama and Donald Trump.

I have no idea what position, if any, these politicians and others take regarding Pluto’s status. What I do know is that whether or not Pluto is viewed as different from the other planets is largely based on the criteria people choose for basing their decisions. Pluto has active geology, cryovolcanism, an atmosphere, interaction between that atmosphere and its surface, and a possible underground ocean. It is geologically layered into core, mantle, and crust. As for its eccentric orbit, Mercury also does not orbit on the same plane as most solar system planets, and many giant exoplanets in individual systems all orbit on different, far more eccentric planes than Pluto.

The argument that “Pluto doesn’t care” what it is called is a straw man. No one is saying Pluto does care. Instead, the point is that we should care because the public is being sold a bill of goods by being taught that one view in an ongoing debate is gospel truth. This is the tremendous disservice to the public caused by the IAU vote.

Why do so many textbooks, media outlets, websites, and educational materials report nothing about the ongoing debate over the status of dwarf planets, instead blindly falling in line with the IAU position? Why did Encyclopedia Britannica wait for the IAU vote to publish its 2006 edition? Both children and adults are being taught a falsehood as truth. They are being led to believe there is consensus on one specific interpretation of the solar system when this is far from the case.

The IAU has had its chance to rectify its mistake of determining what Pluto is before any spacecraft ever visited it and has repeatedly refused to do so. Apparently, only some new discoveries merit reopening the debate. Eris’s discovery does, but New Horizons’ findings of planetary processes on Pluto apparently do not.

Instead of giving this organization a degree of power it has never earned, it is time to look elsewhere for insight into what constitutes a planet. While this is an ever-evolving question that will always change with new discoveries, those we should look to for guidance are the scientists who actually gave us a first-hand view of Pluto, not a group of bureaucrats concerned largely about preserving their own power.

Finally, we often hear the argument that if Pluto were discovered today, it would not be considered a planet. This, too, is an interpretation. As we can see, the status of Eris, discovered in 2005, set off the latest round of this debate, which continues to this day. If Pluto had been found today, scientists would quickly be able to view it with the Hubble Telescope and determine it is spherical. They would be able to tell it is part of a binary planet system with Charon that also has four more tiny moons. They would be able to determine Pluto has an atmosphere and even visit it up close with a probe. It is fair to say that if Pluto were discovered today, the same debate over its status would occur.

Cara’s precociousness is reminiscent of that showed by another young person, who built his own telescopes, observed Mars and Jupiter, and drew very accurate depictions of those planets that earned him the job of searching for a new planet at Lowell Observatory—a planet he discovered 88 years ago today. Clyde Tombaugh never wavered on his position that Pluto is a full-fledged planet. Neither should Cara, and neither should we.

Thursday, December 21, 2017

The Winter Solstice

Four months ago, Americans watched in wonder as a total solar eclipse traversed the nation, and, as many described, “turned day into night.” To many who experienced it, the eclipse was a sublime, even spiritual experience beyond anything words can describe.

Every year during the autumn, day, at least in some sense, turns to night, as the Sun sets earlier and earlier, to the point where, as I often note in frustration, “It gets dark in the middle of the day.” We know this is natural, that it is part of an annual cycle, yet it inspires a range and depth of emotions, from sadness to fear and for some, even fascination.

Those who spend time outdoors during this period can sense the Earth going to sleep and see what is left of life being pulled back into her.

The Winter Solstice, at its core, is about hope. What looks like death is just a period of dormancy. Nature needs the power to restart, and the great generator we call the Sun begins recharging on this day, slowly growing in strength until it opens the slumbering seeds underground and warms the Earth’s frozen surface, drawing the baby plants out into the light.

In an email message today, Sarah Rasmussen of Greenpeace wrote, “There is so much darkness in our world right now, from environmental disasters to climate change…But light is coming to push out the darkness, and we are fighting as hard as we can to ensure that it shines where it will do the most good…The darkest hour is just before the dawn.”

In the natural world, all the major action at the Winter Solstice is beneath the surface, unseen. It isn’t obvious. It can only be felt. Yet this invisible miracle, which from our perspective happens solely because we live on a planet with a 23.5 degree axial tilt, is as real, as profound, as intense as anything can be.

These words, put as a voiceover to a Gaelic version of “Silent Night” by Enya, capture the awe and wonder of this day.

“Yule—the Winter Solstice
Cold and bleak—
The longest night of the year
Though we are in darkness,
We know the Winter Solstice is near.
We light up the long nights with candlelight and evergreens.
We deck the halls with beautiful things.
The Earth is in a deep slumber…
The light is growing dimmer…
But, almost unnoticed,
The Solstice brings its miracle.
There is stillness,
Beautiful and serene…
Peacefully, quietly, the Sun is reborn.
In this small, still moment, the light returns again,
The promise kept
That death is not the end.
From this day, forward, the light and the warmth grow stronger.
But we remember this moment that brings the greatest gift of all.
The light brings with it not only the promise of rebirth,
But (the knowledge that) even in our darkest hour,
The light will always return.
It is the spirit of goodwill,
The warmth of our hearts.
It is peace and joy
That bring us out of the dark.
Give freely of yourself;
Help someone in need;
Bring light to the darkness.
Give hope, and offer peace.
Sending you warm tidings this Yule season.
May your biggest wishes come true!
Eat, drink, and be merry!
A blessed and happy Solstice to you!”

Enya, “Yule, The Winter Solstice,”

It isn’t over. Darkness hasn’t won.

Keep hope alive!

Saturday, November 18, 2017

Help Nickname New Horizons' Second Target

NASA's New Horizons mission to Pluto and the Kuiper Belt is looking for your ideas on what to informally name its next flyby destination, a billion miles (1.6 billion kilometers) past Pluto.

On New Year's Day 2019, the New Horizons spacecraft will fly past a small, frozen world in the Kuiper Belt, at the outer edge of our solar system. The target Kuiper Belt object (KBO) currently goes by the official designation "(486958) 2014 MU69." NASA and the New Horizons team are asking the public for help in giving "MU69" a nickname to use for this exploration target.

"New Horizons made history two years ago with the first close-up look at Pluto, and is now on course for the farthest planetary encounter in the history of spaceflight," said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate in Washington. "We're pleased to bring the public along on this exciting mission of discovery."

After the flyby, NASA and the New Horizons project plan to choose a formal name to submit to the International Astronomical Union, based in part on whether MU69 is found to be a single body, a binary pair, or perhaps a system of multiple objects. The chosen nickname will be used in the interim.
"New Horizons has always been about pure exploration, shedding light on new worlds like we've never seen before," said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.

"Our close encounter with MU69 adds another chapter to this mission's remarkable story. We're excited for the public to help us pick a nickname for our target that captures the excitement of the flyby and awe and inspiration of exploring this new and record-distant body in space."

The naming campaign is hosted by the SETI Institute of Mountain View, California, and led by Mark Showalter, an institute fellow and member of the New Horizons science team. The website includes names currently under consideration; site visitors can vote for their favorites or nominate names they think should be added to the ballot. "The campaign is open to everyone," Showalter said. "We are hoping that somebody out there proposes the perfect, inspiring name for MU69."

The campaign will close at 3 p.m. EST/noon PST on Dec. 1. NASA and the New Horizons team will review the top vote-getters and announce their selection in early January.

Telescopic observations of MU69, which is more than 4 billion miles (6.5 billion kilometers) from Earth, hint at the Kuiper Belt object being either a binary orbiting pair or a contact (stuck together) pair of nearly like-sized bodies – meaning the team might actually need two or more temporary tags for its target.

"Many Kuiper Belt Objects have had informal names at first, before a formal name was proposed. After the flyby, once we know a lot more about this intriguing world, we and NASA will work with the International Astronomical Union to assign a formal name to MU69," Showalter said. "Until then, we're excited to bring people into the mission and share in what will be an amazing flyby on New Year's Eve and New Year's Day, 2019!"

To submit your suggested names and to vote for your favorites, go to:

Media Contacts:
Rebecca McDonald, SETI Institute
(650) 960 4526,
Michael Buckley, Johns Hopkins Applied Physics Laboratory
(240) 228-7536,
Laurie Cantillo, NASA Headquarters
(202) 358-1077,

Atmospheric haze makes Pluto colder than previously thought

Atmospheric haze makes Pluto colder than previously thought