Comets are like cats. They both have tails, and they both do whatever they want to. ~ Francisco Diego
ISON has come and fizzed out, which is a shame. It was dubbed the potential “Comet of the Century” because it was seen to be so bright when still a long way off. Unfortunately, it was a sun-grazer, which means that it got very, very close to the sun. As it turned out, it got too close and broke apart, evaporated, or both.
Because of all the hoopla, The Science Channel stopped showing Survivorman long enough to do an interesting program about the comet and the efforts of scientists to study it. The program was actually reasonably well done, considering they were counting on a big display from ISON and had to scramble a little when they couldn't talk about how it was going to look on the return trip.
So, having enjoyed that program, I was looking forward the other night to a NOVA production on the same subject. I mean NOVA used to be one of the flagship programs of PBS, with beautifully polished programs that presented facts and theories in an entertaining fashion. Well, based on their ISON mashup, the flagship is sinking.
I was suspicious that the show might be less than excellent when they showed a picture of Comet Hale-Bopp and identified it as ISON. In fact, they showed several different comets and called them ISON. Honestly, guys, if you needed pics, you should have contacted Space.com; they've had quite a few.
The Science Channel program consisted mostly of scientific attempts to study ISON. Unfortunately, as is sometimes the case, the attempts they covered kind of fell flat. The first was a balloon launch of a telescope to get it over the main atmosphere. Unfortunately, a latch messed up and the telescope was never usable during its flight. The other biggie was an aircraft-mounted telescope. The plane was absolutely crammed with equipment, apparently a bit too crammed. During two attempts to make observations, a breaker blew out which, after the second attempt, refused to be reset. Even with that mess, the scientists got a little data which they communicated on the show.
Fortunately, for both programs, good old Hubble and SOHO were able to get some terrific pictures and data. SOHO, in particular, followed ISON as it went around the sun. Part of the image was blocked by a disk which covers the sun so you can see what's going on, but the pictures were amazing nonetheless.
I don't know if NOVA had been expecting some more data, but what they presented could be called old-fashioned filler. Comets used to be predictors of doom; in 1910 everyone panicked about the Earth passing through the comet's tail; and that good old standby, there's a chance ISON might hit the Earth. That last item came when the only person on the planet who calculates cometary orbits (that's basically what they said), decided that there was a possibility of a collision with Earth—based on two data points. Oh, and that was one outcome of a possible 600 orbits. After a few more observations, he decided to call off the apocalypse.
And yes, there was footage of the Russian meteor (which wasn't even a cometary object, for crying out loud).
Then came this doozy. Seems Isaac Newton developed his theory of gravity because of a question Edmund Halley asked him. Seems Halley was interested in comets and asked Newton what orbit one would take. Newton immediately said it would be an ellipse but he hadn't rigorously worked it out yet. In a few days, though, he whipped out the formulas. So Newton's theory of gravity never would have happened without a comet.
T'warnt the way I heard it. The way I heard it, Halley asked Newton what sort of orbit a planet would take when subjected to an inverse-square force. Newton gave the same answer: An ellipse, but he hadn't worked out the details yet. Newton then spent 18 months creating the Principia Mathematica, which Halley had to pester him to publish (in fact, Halley footed the bill). NOTE: The link notes some issues even with this story and has a lot of math, but the point is that the discussion wasn't about comets.
But the capper came when the programs turned to makeup and mechanics of a comet. On NOVA, one scientist placed a little piece of frozen carbon dioxide in a pan of water so it could fizz around like an Alka-Selzer. That, she explained, is what happens to a comet as the CO2 outgasses in space. Then another scientist through a bunch of stuff in a little bucket, pulled out a baseball-sized hunk of snow and dirt and told us this is what a comet looks like.
Okay, accurate as far it goes, but not very impressive. What did Science do? They built a comet. In an industrial ice-cream facility with a freezer the size of a hangar, a scientist (one of the Deep Impact guys) put together a three or four foot irregular glob of dirt, carbon dioxide, water and whatever else he needed to make a mini-comet. It showed the kinds of icing features one would expect which was climaxed by getting a short but impressive burst of gas from the inside which is exactly how CO2 jets out of a real comet.
So kudos to the Science channel for actually doing some science reporting. This was a program about comet ISON, why it could have been an amazing comet, and what its ultimate fate was.
And brickbats to NOVA for creating a canned mishmash that was a standard How the Universe Works sort of show. There's nothing wrong with that sort of thing (at least HTUW usually gets it science history right), but it is most certainly not an in-depth look at a particular astronomical event. All that was missing from the NOVA program was Michio Kaku telling us they were “going to have to rewrite the textbooks” once ISON came by.
So it could have been worse.