Winnipeg Free Press - PRINT EDITION

In defence of Pluto

But what's better — being a runt or the king of dwarf planets?

  • Print

MELVILLE, N.Y. -- Pluto, a distant world on the frigid outskirts of the solar system, was downgraded eight years ago when scientists changed its status from full-fledged planet to planetary dwarf.

Scores of Pluto fans booed the decision and terminology -- dwarf planet -- imposed by the International Astronomical Union, which voted in Prague to reduce the number of planets to eight.

Controversy has yet to wane. There's a Face-book page devoted to reinstating Pluto. Elsewhere, a permanent online petition still invites the public to voice disagreement with the union. And the editor of a popular astronomy magazine is calling for a presidential-style debate to settle Pluto's status in the heavens -- once and for all.

The maelstrom mounts as Earthlings prepare for a first-ever rendezvous: An American data-gathering spacecraft will make a historic Pluto flyby next year. Ironically, the New Horizon space probe was launched the year the far-flung orb was demoted.

The spacecraft will hurtle breathtakingly close to the Plutonian surface, having traveled seven years and 4.5 billion miles to reach Pluto, deep in the icy Kuiper belt.

Astronomers are certain new insights will emerge from the mission, but that probably won't change Pluto's status, they say.

"Clearly, Pluto is a touchy subject," said Fred Walter, a professor of astronomy at Stony Brook University.

As Walter sees it, powerful scientific evidence undergirded Pluto's downgrade from planet to dwarf.

"It has the most extreme orbit of any of the planets, at least when it was a planet," Walter said, noting Pluto, about the size of Earth's moon, is highly dependent on a larger, full-fledged celestial body, a guardian planet in the cosmos.

"Pluto isn't gravitationally independent," Walter added. "It's gravitationally tied to Neptune."

But just as mystery has shrouded Pluto because of its multibillion-mile distance from Earth, semantics have affected it, too, Walter said.

"We haven't really fully demoted Pluto. The word 'planet' is still there," he said, referring to the term dwarf planet.

"But if you were Pluto," he asked, "would you rather be the runt among planets, or the king of the dwarf planets?"

Denton Ebel, who chairs the earth and planetary sciences department at the American Museum of Natural History in Manhattan, cringes at the thought of "the Pluto discussion."

Discord, he asserted, is inevitable when the subject is Pluto. He doesn't think it's a full-fledged planet, either.

He scoffs at Pluto proponents who say scientists are prejudiced just because it's small. "It's not in the same class of objects as Earth and Mars and the other bodies we think of as planets," Ebel said. "There's an object in the Kuiper belt that is larger than Pluto, and it isn't a planet.

"There are lots of objects out there and we are still finding new ones. But everything can't be a planet."

In recent years, space hunters have found hundreds of new objects in the Kuiper belt, Pluto's home, a region far beyond the solar system. Ebel refers to the area as the deep freeze, a vast expanse populated by comets and alien planet-like objects.

On Pluto itself, the average temperature is minus 380 degrees. And, it's not just dark, it's superdark: Sunlight is 1,000 times fainter than on Earth.

Scientists who oppose Pluto's return to full planetary status say it may have been misdesignated upon discovery in 1930 by Clyde Tombaugh at the Lowell Observatory in Arizona.

Tombaugh died in 1997, but a portion of his ashes was placed aboard the New Horizon probe and are en route to the world once called Planet X. In 1930, there were no official definitions of a planet.

Before 1996, Walter said, "no one ever sat down and determined what a planet is."

The astronomical union has three key criteria for a celestial body to make the cut. Dinky Pluto had trouble making the grade.

The union's rules say a planet must orbit the sun and be massive enough to exist in "hydrostatic equilibrium," which means having its own potent gravitational pull. Hydrostatic equilibrium is the reason planets are spherical.

The third criterion: A planet must "clear the neighbourhood" of smaller bodies within its orbit. This complicated wording means a planet must be dominant in its orbital zone, Ebel said, and Pluto isn't because it's in a complex dance with several satellites surrounding it.

Yet, Pluto's ban from the solar system still stokes powerful emotions in legions of fans.

"In my heart, I know that it really can't be a planet anymore," said Ken Spencer, an amateur astronomer and president of the Astronomical Society of Long Island. "I was really sad to see it demoted. But after reading why, it's hard to argue with those reasons."


-- Newsday

 

Republished from the Winnipeg Free Press print edition August 9, 2014 D6

Fact Check

Fact Check

Have you found an error, or know of something we’ve missed in one of our stories?
Please use the form below and let us know.

* Required
  • Please post the headline of the story or the title of the video with the error.

  • Please post exactly what was wrong with the story.

  • Please indicate your source for the correct information.

  • Yes

    No

  • This will only be used to contact you if we have a question about your submission, it will not be used to identify you or be published.

  • Cancel

Having problems with the form?

Contact Us Directly
  • Print

You can comment on most stories on winnipegfreepress.com. You can also agree or disagree with other comments. All you need to do is be a Winnipeg Free Press print or e-edition subscriber to join the conversation and give your feedback.

You can comment on most stories on winnipegfreepress.com. You can also agree or disagree with other comments. All you need to do is be a Winnipeg Free Press print or e-edition subscriber to join the conversation and give your feedback.

Have Your Say

New to commenting? Check out our Frequently Asked Questions.

Have Your Say

Comments are open to Winnipeg Free Press print or e-edition subscribers only. why?

Have Your Say

Comments are open to Winnipeg Free Press Subscribers only. why?

The Winnipeg Free Press does not necessarily endorse any of the views posted. By submitting your comment, you agree to our Terms and Conditions. These terms were revised effective April 16, 2010.

letters

Make text: Larger | Smaller

LATEST VIDEO

Key of Bart: NDP Self-Destruction

View more like this

Photo Store Gallery

  • Goslings enjoy Fridays warm weather to soak up some sun and gobble some grass on Heckla Ave in Winnipeg Friday afternoon- See Bryksa’s 30 DAY goose challenge - May 18, 2012   (JOE BRYKSA / WINNIPEG FREE PRESS)
  • A young gosling prepares to eat dandelions on King Edward St Thursday morning-See Bryksa 30 Day goose challenge- Day 17- bonus - May 24, 2012   (JOE BRYKSA / WINNIPEG FREE PRESS)

View More Gallery Photos

Poll

How much does the premier's apology mean to you?

View Results

View Related Story

Ads by Google