Pluto’s big comeback: Why it could be reclassified as a planet 

New research reveals the "trans-Neptunian object\'s" impressive planetary resumé

Topics: Scientific American, Science, Space, Pluto, Solar System, Innovation News, News

This article was originally published by Scientific American.

Poor little Pluto. In 2006 astronomers ganged up on it and voted to strip it of its planethood—but other astronomers signed a petition saying they’d ignore that vote.

Now Pluto itself seems to be fighting back. Thanks to the Hubble Space Telescope, we’ve learned that Pluto has at least five moons—pretty impressive for something that’s supposedly not a planet.

And new research suggests Pluto is just what we were taught long ago: the largest world orbiting the sun beyond Neptune.

In 2005 astronomers discovered Pluto’s greatest rival, Eris. It’s three times farther from the sun than Pluto. And Eris was thought to be bigger than Pluto, too. But that initial estimate may have been wrong.

Other astronomers have now analyzed methane in Pluto’s air. Yup, Pluto has an atmosphere—again, pretty impressive for something that’s supposedly not a planet—and the methane suggests Pluto is about 1,471 miles across, versus just 1,445 miles across for Eris. The new study appears in the journal 

Exploring the spatial, temporal, and vertical distribution of methane in Pluto’s atmosphere]

We’ll find out its exact diameter in July 2015, when NASA’s first spacecraft to Pluto zips by. It’ll take lots of pictures, probably find more moons and hopefully tell us whether Pluto is indeed the king of the underworld—I mean, of the solar system beyond Neptune.

Listen up, America: It’s time to starting making mass transit free!

This is your brain on racism: Inside the mind of modern bigotry

Listen up, America: It\'s time to starting making mass transit free!

Google\'s next plan: Collect medical data to create a detailed map of a healthy human being

The pill might change the way women perceive other women

A woman with deadly Ebola virus escapes quarantine, now loose in a city of 1 million

"I was probably laid off by a computer": Ex-Microsoft employee sounds off

by Apple\'s major iPhone plan" href="http://www.salon.com/2014/07/25/conan_is_not_impressed_that_apple_will_use_robots_to_build_next_iphone/" class="plain gaTrackLinkEvent" data-ga-track-json=\'["morerelatedstories", "click", "Conan is <em>not impressed</em> by Apple's major iPhone plan"]\' >

by Apple\'s major iPhone plan" data-source-standard="http://media.salon.com/2014/07/Screen-Shot-2014-07-25-at-9.53.28-AM-150x150.png"/> Conan is

WATCH: The technology of the future blows Stephen Colbert\'s mind

The plot to destroy education: Why technology could ruin American classrooms — by trying to fix them

Science according to Tara Reid: "There could be a sharknado"

Jimmy Kimmel pranks Apple lovers by showing off the new "iWatch"

Amazon to authors: Pipe down about publishing war

The new "menstrual activism": Young women on YouTube, talking about their periods

Stephen Colbert skewers libertarian scheme: "I\'m tired of the whole idea of a melting pot in America"

Twitter releases diversity report, admits "we have a lot of work to do"

Researchers: Our best shot for finding aliens is to look for their pollution

Education "reform\'s" new Ann Coulter: A reeling Michelle Rhee passes the lead to Campbell Brown

"Weird Al" gets his first No. 1 record after releasing his 8 hilarious videos in 8 days

"Roman Candle" turns 20: Secrets of Elliott Smith\'s accidental masterpiece (slideshow)

Elliott and the friends with whom he recorded in middle school in Texas (photo courtesy of Dan Pickering)

Heatmiser publicity shot (L-R: Tony Lash, Brandt Peterson, Neil Gust, Elliott Smith) (photo courtesy of JJ Gonson photography)

Elliott and JJ Gonson (photo courtesy of JJ Gonson photography)

"Stray" 7-inch, Cavity Search Records (photo courtesy of JJ Gonson photography)

Elliott with "Le Domino," the guitar he used on "Roman Candle" (courtesy of JJ Gonson photography)

Full "Roman Candle" record cover (courtesy of JJ Gonson photography)

Elliott goofing off in Portland (courtesy of JJ Gonson photography)

Heatmiser (L-R: Elliott Smith, Neil Gust, Tony Lash, Brandt Peterson)(courtesy of JJ Gonson photography)

The Greenhouse Sleeve -- Cassette sleeve from Murder of Crows release, 1988, with first appearance of Condor Avenue (photo courtesy of Glynnis Fawkes)

Make Summer More Poetic with These 10 International Works

8 Illustrated Books for Every Age and Every Summer Reading List

10 Great Science Reads That You Can Take to the Beach

Turn Summer into a Literary Field Day with these 9 Collections of Non-Fiction Sports Writing

Travel to Foreign Lands in 10 Newly Translated Novels

Get Lost in 8 Great Biographies – from Lawrence of Arabia to Margaret Fuller

Explore Diverse Cultures Through Varied Genres with These 8 New Works

8 Great Essay Collections for Your Reading Pleasure

Looking for Fresh Fiction for your Summer Reading?

Tough love: An intimate look at Mexico City\'s retired (and semi-retired) sex workers

The best and worst series finale music of all time

They\'re no "Divergent": Eight young-adult movie franchises that died untimely deaths

Space porn: These images are (quite literally) out of this world

Salon is proud to feature content from Scientific American, the longest continuously published magazine in the United States and the leading popular source and authority on science, technology and innovation. With a worldwide print and digital audience of more than five million people, fourteen local language editions, and a major new

blog network, Scientific American engages, educates and inspires current and future generations of science-interested citizens and public and private sector leaders.

The modern history of swearing: Where all the dirtiest words come from Melissa Mohr

I\'m the mom whose baby photos you\'re blocking on Facebook Kirsten Clodfelter

Paul Krugman: California proves the GOP\'s "extremist ideology ... is nonsense" Elias Isquith

Anal sex: Science\'s last taboo Debby Herbenick

5 reasons it\'s time for a 4-day work week Lynn Stuart Parramore, AlterNet

Texas gun nuts\' scary ritual: How hatred of a president turned profane Heather Digby Parton

5 vitamins and minerals that are actually worth taking Joseph Stomberg, Smithsonian.com

ESPN commentator: Women should take responsibility for "provocation" when they are assaulted Katie Mcdonough

Comedy vs. anti-science: 10 amazing videos that show how humor

A woman with deadly Ebola virus escapes quarantine, now loose in a city of 1 million Sarah Gray

5 countries that love America (and 5 that hate it) Sarah Wolfe, GlobalPost

The right\'s new enemy No. 1: How the Chamber of Commerce became toxic Jim Newell

Jack White Crashes Beck\'s Encore in Providence

Nicki Minaj Summons Her Superpowers as a Cartoon in \'Steven Universe\'

Take an Early Peek at the \'Simpsons\'-\'Family Guy\' Crossover Episode

Jack White to Throw First Pitch at Detroit Tigers Game

John Boehner Uses Billy Joel Puns to Blast Obama\'s Jobs Plan

The Jerk Thing Pet Owners Have No Clue They\'re Doing

An Admittedly Sexist Man Sent Her An Email ... She Was Happy To Respond

TV Host Loses His Sh*t After A Football Player Gets An Unbelievable Punishment For Beating His Wife

Everything That Was Wrong With \'We Are The World\' They Got Right In This Celebrity Music Project

2 Teenagers Destroyed Countless Families. So These Guys Tried To Understand Why.

SALON ® is registered in the U.S. Patent and Trademark Office as a trademark of Salon Media Group Inc.