* Quake (well, original Quake with software rendering)
and on and on, but I really wanted to get "Multitasking" in there.
the only thing you have going for your clinging to pluto is adherence to tradition.
If this is addressed to me, I think you misunderstand me. I fully agree that there's no more reason to call Pluto a planet than Quaoar, Sedna, Ceres, and lots of other stuff. Tradition (of the last 75 years) would call Pluto a planet but not Sedna, and I agree that makes no sense. I think, though, that the thing to aim for in a definition of "planet" (if it needs to be defined at all) is "the sort of thing that planetary scientists study", and that category definitely includes asteroids and TNOs and comets, and is starting to include extrasolar planets. I also believe that a definition that includes them would be less arbitrary and ambiguous than the IAU's current one.
Ultimately, it's just semantics. However, if the categories we use slow down discovery by making it harder to take seriously, fund, and disseminate the work of people studying TNOs and asteroids than to take seriously the work of (much better understood, by and large) classical terrestrial planets, then I don't think the categories are well chosen.
Now, I don't think planetary scientists, for the most part, make their decisions based on arbitrary terminology. But to take a concrete example, given how precarious its funding seemed from time to time, I suspect New Horizons would not have gotten funded if Pluto had never been considered a planet. And that would have been a shame. It will similarly be a shame if in 2035 a probe to Haumea doesn't get funded because Congress or the Duma or the National People's Congress thinks it doesn't make sense to spend that kind of money on something that isn't even a planet. Planetary scientists know the IAU definition is just one arbitrary place to draw the line, and that Pluto (and Eris and Makemake and Haumea) are probably going to be just as rewarding to study as Mercury, but to the extent that the terminology stands in the way of the wider culture understanding that, it's kind of unfortunate.
I have to say, I'm kind of fond of the "four planets and some rubble" definition, though.
your choice, but the third graders of 2080 who have to memorize 80 planets might not be too happy with you
Once upon a time, students had to memorize only four elements (earth, air, fire, and water). Nowadays we recognize over a hundred, and there are a bunch of theoretical ones we can predict but have a hard time detecting. I don’t think “but people will have a hard time remembering them all, so we have to add arbitrary limit so that we don’t have so many” is a very good way of defining terms.
I can see a good argument for saying that the solar system contains four planets and some rubble. I can see an argument for saying that it contains over a dozen planets, probably way over. I can see a good argument for saying that it consists tens of thousands of planets. I can see a good argument for saying that “planet” is not a piece of scientific terminology and letting lay usage define it.
I can see an argument, although not a great one, for coming up with a definition that keeps the number down to a dozen, but I think the definition the IAU came up with is pretty ambiguous, since “cleared the neighbourhood around its orbit” is clearly relative, and you could define “cleared”, “neighbourhood”, and “around” in such a way that Ceres has done it (admittedly a stretch), or that Jupiter hasn’t. (There’s also the matter of “has” — do things that weren’t planets early in the history of the solar system become planets as time passes and they collect impacts?) And the IAU definition explicitly excludes anything that orbits around any star other than our sun, which to my mind makes it just silly, and means that a sizable fraction of the astronomical community is concerned with studying planets (and publishing papers calling them planets) that do not meet the IAU definition.
Incidentally, once upon a time, any new thing discovered in orbit in the solar system other than the sun was considered a planet, so the moon, the moons of Jupiter, and the asteroids (the few then known) would all have been considered planets. If you exclude dust particles and the like, that’s still a reasonable definition for the sorts of things that “planetary scientists” study, and personally I kind of like that approach.
First of all you're going to need a stable tripod, probably costing as much as the telescope itself.
It's designed to work with a camera tripod, which works well since it's so light. But the other night I was able to get a pretty good (if very small) view of Jupiter and a couple of its larger moons just bracing my elbows on a porch railing. When Saturn's inclination with respect to the earth is such that its rings are easy to see (not the case right now), I'm sure you'll be able to see them (meaning see that they exist, not necessarily get a good clear view) without a tripod.
(I got one for myself and one for my girlfriend, and I think it was a great purchase. The instructions that came with the kit were ambiguous and incomplete, but there's a good thorough PDF with photos on the web site.)
Tomorrow's computers some time next month. -- DEC