The Comet PanSTARRS has been within view for about a week now, but the Kalamazoo Astronomical Society has been waiting for a weekend to plan their public watch party. K.A.S. President Richard Bell says a comet is basically a piece of ice and rock leftover from when the planets were formed.
Former president Mike Sinclair describes it this way:
“Like a dirty snowball. Carbon dioxide, there’s a fair amount of that. Lot of outgassing, which is one reason you see the coma and the tail.”
The coma is the cloud of gas around the center of a comet.
“Water, they found organic compounds in the tails and around the comas—generally by spectroscopic analysis," Sinclair says. "Dirt, rock, you name it. It’s just a mixture of everything.”
The comet will be very low in the sky at sunset and hard to see without a good, open area. Bell says with the naked eye, at best the comet will look like a fuzzy patch in the sky with, possibly, tail. He says there’s a lot more to see with a small telescope or even a pair of binoculars.
“Cause everyone could enjoy Hale Bopp and Hyakutake, those are the bright comets in ’97 and ’96 respectfully. And close up you could see a lot of detail around the nucleus—like the actual comet, the actual ‘dirty snowball’ as we them. And so yeah, You definitely get a different view when you see these things up close," Bell says. "You can see a lot more structure in the inner coma, which is the comet’s sort of ‘head’ and you can even see some filamentary structure in the tail if it has a nice tail.”
“One of the examples you could see in Hale Bopp in ’97 is was that the leading edge of it you could see bow shock," Sinclair adds. "You could actually see…it looked like little wave forms in front of it. Kind of like a wave…like little wave shock you get in front of a ship as you’re kind of riding them on rough water you can see this kind of form in front of it. And astrophotographs showed three distinctive tails in Hale Bopp. We could see two pretty clearly, but you could actually see a third one that was kind of in between in astrophotographs. And I think that may be one of the things we’ll be looking for is, ‘What will the pictures reveal?’”
At first, Comet PanSTARRS was predicted to be about as bright as Venus, but that doesn’t seem to be the case anymore.
“Comets are very unpredictable," says Bell. "They could either suddenly experience a massive outburst and, you know, brighten rapidly—which of course is good—or it could just fizzle out.”
“It’s all just guesswork," Sinclair says. "They look at brightness curves. They look at their light curves as they approach from six to eight months behind us and they are trying to estimate how bright it’s going to be. And they make these kind of reasonable…what they believe is a reasonable prediction. And then about half the time it’s not as bright as they predict, and once in a while you get a really bright one out of it. And PanSTARRS is one of the ones they had high hopes early on and it seems to have kind faded a little bit. A lot of it, I think, has to do with its position in the sky.”
PanSTARRS may be a pretty ‘average’ comet. But if astronomy were football, this would just be the playoffs. Bell says there is a brighter, more spectacular comet on its way.
“This is the warm-up for Comet ISON which will be at its peak hopefully in late November and December of this year," he says. "And at maximum, the upper limits are this comet will be as bright as the full moon, although it will be very close to the sun at this time. So it’ll be able like a little fuzzy patch near the sun. But of course, you should be very careful looking at it like that. You have to kind of block the sun out with building or something like that. But it’ll move into the both morning and evening sky in December. And it might be as bright as Venus then. And it might be the brightest comet in centuries or maybe ever.”
You can join Richard Bell, Mike Sinclair, and other members of the Kalamazoo Astronomical Society to see Comet Pan-STARRS. The event will be held Friday and Saturday night at 7 p.m. in Richland Township Park. If you miss it this weekend, Bell says the comet should still be visible until Wednesday.
