ISON not weather but still something to watch

jamesmseitz

jamesmseitz

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Later this year Comet ISON is forecast by some that to pass so close to the earth and be so bright that it would rival a full moon or brighter. Ison is just inside Jupiter's orbit but already has a tail of 40,000 miles and still growing. Also on Dec 26th ISON is projected to pass about only 40 million miles from the Earth as well. If this happens that would be something to behold. Here is the link to the info if someone wants to read in full.

http://news.yahoo.com/nasa-probe-snaps-photos-potential-comet-century-115251441.html
 
Cool. I can't wait.

I'm not saying it couldn't be spectacular, but I'm always wary when a news service says anything will be as bright as the full moon. Or as large as the full moon, etc. (Ever had a friend forward those stupid mars emails that show up now and then?) My guess is they misunderstood what they were told about their comparative magnitudes.

But hey, prove me wrong, Comet ISON. Go nuts! :)
 
If I'm understanding this correctly, the comet is at its brightest when its extremely close to the sun, thus you see it at that brightness when the sun is up (or just below the horizon). It's going to look a lot more like a sun dog that's very close to the sun, maybe even like the sun has an extra lobe, than it is a huge glowing moon at the top of the night sky. Sun dogs are brighter than than the full moon, but during the day this is much less impressive than if it occurred at night. When the comet is visible in the middle of the night, it's going to be further from the sun and much dimmer. The brightness magnitudes may be correct, but I think folks are expecting to be able to read books at midnight under comet light, not realizing that the comet's brightness won't peak until the sun is up. Still, snagging a photo of it on the horizon before the sun comes up could be spectacular. I'll definitely be watching for it!
 
I think it all depends on where the earth is in it's orbit at the time the comet comes closest to the sun and how close it gets. It can be at it's closest and still be in the night sky. In this case, (somebody correct me if I'm wrong here), I think it may pass behind the sun at it's closest, but should emerge from the other side and have the potential for a great nighttime show.

But comets are notoriously hard to predict. Some that were predicted to be mediocre have had spectacular flareups. Some that were supposed to be awesome instead fizzled.
 
Orbit_comet_2012_S1_ISON.png


IAU's Minor Planet Center suggest that Comet ISON could peak at magnitude –10 or brighter at perihelion (when it will be just 1° from the Sun)
Click to expand...

http://www.skyandtelescope.com/comm.../A-Dream-Comet-Heading-Our-Way-171521041.html

There's so little separation there that it may be hard to even pick the comet out against the sun it sounds like. What could be really really cool is if the comet is still sporting a long tail when its outbound and closest to earth. We'll have quite the show then (even if it is much dimmer than when it peaks closest to the sun).
 
Skip Talbot said:
There's so little separation there that it may be hard to even pick the comet out against the sun it sounds like.
Click to expand...

Yes, you're right, but I wouldn't worry about it. That's pretty normal. It will be at it's brightest during the times we can't see it from the ground on Earth and dimmer when it is visible in the night sky. But hopefully it will still be good enough during those times. And it looks like the relative positions of Earth, Sun and comet could have been a lot worse.

Skip, do you have a telescope? It'd be real easy to blind yourself trying to get a glimpse while near the sun. I wouldn't even try it. I have a solar filter for mine that cuts out 99% of the light, but it's near impossible to see anything dim near the sun while using it.
 
Todd Renshaw said:
Skip, do you have a telescope? It'd be real easy to blind yourself trying to get a glimpse while near the sun. I wouldn't even try it. I have a solar filter for mine that cuts out 99% of the light, but it's near impossible to see anything dim near the sun while using it.
Click to expand...

Nope, if I did anything with this comet it might be to and try and snag a photograph of it just before dawn or just after sunset if it's still above the horizon. I don't have the best equipment for that, and I'm sure tens of thousands of other photographers will be going for the same shots, but it would be cool to attempt just for personal use or in a different context that others aren't getting.
 
That kind of shot should be easily achievable and would probably look better near the horizon than higher up in the sky. Go for it. (I don't think you need any spectacular equipment for that.) If the tails are really long, you can't capture it all using a telescope anyway.

And if this thing really turns out bright, maybe even a shot above a city skyline would work out great. If it doesn't live up to expectations, you might have to find a secluded dark sky away from any light pollution to make it work.
 
I may be repeating what has already been said, but predicting brightness of comets in advance is like predicting snowfall totals.....very hard to pinpoint with accuracy. These sun-grazing comets sometimes don't return from the other side, because they were essentially destroyed by the sun. Even though the brightness of a comet is at a maximum when it is nearest the sun, the glare will offset the max. brightness. Therefore, when the comet swings away from the sun, and is higher in a dark sky, it will be seen better, even though it is not as bright. (because of contrast against the sky). Comet ISON is not due until November, but we have 2 comets due to arrive quite soon.....Comet Lemmon at the end of this month, and Comet PANSTARRS in March. The latter could be naked eye visibility. One of the best sites for these events is Spaceweather.com, if I am allowed to mention this.
 
I know that the odds are greater that this might be a dud but still after Hale-Bopp Been hungry to see another comet like that. This one at least there is hope to see a tail in the night sky.
 
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