Comet ISON: Pop or Fizzle?

In this Hubble Space Telescope composite image taken in April 2013, comet ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Will the much talked about comet ISON, discovered by Russian amateur  astronomers last year, turn out to be what some are calling the ‘comet of the century’ ? Not likely, says one researcher who has just concluded a preliminary study using the latest observations of the icy interloper. (Related: “New Comet Discovered.”)

Astronomer Ignacio Ferrin, from the University of Antioquia in Medellin, Colombia, believes that comet C/2012 S1 ISON may possibly  fall apart before even reaching its closest encounter with the sun later this fall.

Stargazers were initially very excited when astronomers calculated the comet’s orbit and they realized it would be skimming the sun’s surface by only 700,000 miles (1.1 million kilometers) on November 28, 2013. But continual observations by both professional and amateur telescopes, including Hubble, have since shown that the comet has not brightened as expected.

“Comet ISON has presented a peculiar behavior,” said Ferrin in a press statement.

“The light curve has exhibited a ‘slowdown event’ characterized by a constant brightness with no indication of a brightness increase tendency. This slowdown took place around January 13, 2013. For 132 days after that date, and up to the last available observation, the brightness has remained constant.”

Ferrin interprets this lackluster behavior as meaning that the comet may not live up to all the hoopla.

That’s because during its closest encounter with the sun, the comet’s three-mile (five-kilometer) wide icy core – in the worst case scenarios- will either be torn apart by intense solar gravitational forces, or simply melted away by the scorching 2,700 degree temperatures, Ferrin says.

The consensus in the astronomical community is that it is especially unlikely that ISON will flare up to be as bright as the full moon, as some media accounts have reported.

For now, however, the comet is still currently out between the orbits of Mars and Jupiter, hurtling towards the Sun at 48,000 miles (77,000 kilometers) an hour. The latest infrared views from NASA’s Spitzer Space Telescope—taken in June—shows ISON’s nucleus spewing out a healthy 186,000-mile-long (299,000-kilometer-long) tail of carbon dioxide and dust as it melts due to the sun’s heat.

Will comet ISON blossom into a naked-eye comet, sporting a long, beautiful tail across the sky? Comets are notoriously unpredictable and can surprise even experts. Unfortunately, it’s now a wait-and-see game since the comet is currently lost in the glare of the sun and will only be visible again in early September.

One thing is for sure, ISON will make an uncomfortably close approach to the sun in just a few months. Thanks to an armada of telescopes on Earth and in space trained on this cosmic event, we will be witness to a rare spectacle no matter what’s in store for this sun-grazer.


Follow Andrew Fazekas, the Night Sky Guy, on Twitter and Facebook.

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.
  • william cook

    i’m interested pls keep me posted

  • włochaty

    The best comet ISON flyby simulation there is:

  • Comet C/2012 S1 ISON Facebook Page

    Comet C/2012 S1 ISON Facebook Page – http://facebook.com/C2012S1

  • Lea Beckman

    I hope this is not super massive armagedon, if it is we are doomed. it’s kinda like the movie Knowing.

  • Stephen Y

    If you continue to hold that it a gravitationally controlled universe/solar system instead of all of the evidence pointing to the stronger electromatic model, you won’t understand that the “brightness” is dependent upon the relative charge between the sun and the comet.

  • spinning star

    I don’t give a dime to the doomsday theorists. But I see the story of Nibiru is mentioned anywhere in the anctient worlds, maps (space cartography) we don’t believe are anctient and not “just” centuries or milenias old.
    We have a crashing moon loose outhere … and we all know there’s between Mars and Jupiter a thick, some refere as “too much material for a single planet” asteroid field (or inner belt), and an external icy comet also field or belt)…
    I think Celes, the planet of the angels and it’s twin planet orbiting togheter turnning each other had an anctient “ball 8 pull crash” terror act, from “big, big enemies men always had”… hidden in power positions, infiltrated… nets…

  • anthony

    the knowing was a film about the suns super flares.


    interesting way to follow ISON – real-time visualization

  • syney

    Comet ison is the coolest comet on earth i cant what till Nov.28,2013

About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (dbraun@ngs.org)

Social Media