Posted on by Bob King

Hubble Looks but Finds No Trace of Comet ISON

On December 18, the Hubble Space Telescope slewed to Comet ISON’s expected position and found nothing down to the incredibly faint magnitude of 25. According to astronomer Hal Weaver, who planned the ISON search, that limit implies any remaining fragments would have to be smaller than about 500 feet (160 meters) in diameter. 

Composite photo of one of two Comet ISON locations photographed by the Hubble in a way that suppresses features not in the same place. No trace of the comet is visible. Credit: NASA/ESA
Composite photo of one of two Comet ISON locations photographed by the Hubble Space Telescope. No trace of the comet is visible. Credit: NASA/ESA

Nothing is visible in any of the images in the photo panel except trailed stars and galaxies, reflections and the occasional zap of a cosmic ray. After ISON was torn asunder by the sun, there existed the possibility that comet’s remains would follow a slightly different orbit. To make sure he was covered, Weaver photographed two separate comet positions, stacking several exposures together.

Comet ISON photographed at a second location. Again, nothing detected. Credit: NASA/ESA
Comet ISON photographed at a second location. Again, nothing detected. Credit: NASA/ESA

“The images have been combined so that features not at the same place in the various images are suppressed. Any comet fragments would show up more clearly in this composite, though stars still show up as faint streaks”, writes Zolt Lavay, author of the ISONblog at the Hubble site.

Again, nothing shows up in these either. While no one can say that ISON has completely disappeared, we now know that at the very least it’s broken into pieces too small for even Hubble to see. What was once a beautiful sight in binoculars has expanded into a vast cloud of gas and dust thinner than Ebenezer Scrooge’s gruel.

30 Replies to “Hubble Looks but Finds No Trace of Comet ISON”

    1. There is one way only, to find what you are looking for, of what remains. In two days, way more space. Counter-reflection -> slight change of angle, pt. + 01 up (is it still points?). It’s not going to hang around to make you happy. Basically, you stand no chance. Still, hubble it and be quick!

      For Dogov’s sake, dont just look, find it.

    1. Although, not convinced by what is described here as Scattered light, honestly, please review and get back to us.

  5. The comet of the century just gone like that. I was so looking forward to it’s pass on the way back. Thanks so much for the pics astroglide Bob.

  11. I have this incredible annoying 5 series of icons at the center left om my screen with the FB, Twitter, G+ Pinterest and email that screams for attention and even blocks my text of Universe Today.

    I did not have this a couple hours ago. It is really frustrating and you start to hate these 5 icons and what they represent.

      2. I understand that and I would not mind discreet ads on the side, like they have on the SpaceWeather.com website, but when the bloody ads encroach on the article that one is reading, it gets very annoying and is more likely to put off readers from reading the article.

      1. Ok in that case. I use Firefox 26.0
        Delete this post when you do not need the feed-back anymore.

        Screen 1920×1080
        When I resize the width about half then the panels dissapear.
        The panels are way too big in size to be useful.
        If you reduce them to 1/4 the and not in the horizontal centre then it would mind less. Lower bottom would be good I think.

        When the FF screen is a bit more than half the screen then the panel actually overlaps parts of the text. Especially when one of the mouse cursors is over it and the panel expanded a bit more to the right.

        What is annoying is that it gets your concentration away from the article. It screams like “look at me”. And when you move the mouse over it then the dynamic resized screams even harder. Getting attention is good but when it attracts so much attention then people stay away from your articles too.

        I do have the tendency to scroll the page to a point where any ads is off-screen. I have seen the ads, I have acknowledged the ads but did not follow it. But here we have a situation where the icons follows you even if I have decided that it is not for me. It feels like stalking.

        I actually think that right lower border and much smaller would be less intrusive. I doubt that people would follow links when they get the feeling that it stalks them. It actually makes people hate the icons associated with it.

      2. well, i mean, i’m happy they’re not covering the text. so i will leave the width alone.

  12. Looking for love (ISON…) in all the wrong places, perhaps? Could not the tumbling breakup seen after perihelion have caused the larger fragments to tumble outside of the predicted path for a surviving solid nucleus, like billiard balls or shotgun pellets always do? Sorry to say this, but seems that NASA is being less thorough than one would hope. Weren’t they also looking in the wrong spot during the perihelion live show, where they said nothing survived? Now move along citizens, nothing to see here, we’re in charge, no need for panic…

  13. I’d love to get some good estimates of some of the details not readily available to us mere mortals like distance from solar surface at perihelion, maximum velocity and tidal forces at perihelion and the temperature and density of the corona at perihelion.

    I’d also love to see a good computer simulation of ISON’s final few hours. I regret ISON not surviving to be a spectacular sight, but I think the disintegration of ISON was an incredible learning experience.

    I know STEREO and SOHO have a number of instruments that study the solar surface directly. Was ISON captured by any of these instruments as well, or was it just too dim and small?

    1. all the data that you ask about has been readily available for several months. SOHO, both STEREO’s, SDO, HST, MESSENGER, MRO, Swift, SST, Deep Impact and other spacecrafts took detailed pictures of ISON. computer simulations of the comet trajectory are also widely available. The prevailing discussions now are suggestions that the comet was possibly composed of a large volume of exotic ices that out gassed early and made it visible while still in a region of our Solar System where water is still in a solid state.

      1. I’ve seen a few estimates of size, speed and distance from the sun, but this was prior to perihelion. I’m guessing that the numbers we have now are more accurate but news about ISON after its becoming an ex-comet has been pretty sparse.

Comments are closed.