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Using Shadows To Measure the Geysers of Enceladus
The Bad Astronomer writes "A lot of folks are posting about the amazing new pictures of the icy moon Enceladus returned from the Cassini spacecraft. However, one of them shows the shadow of the moon across the geyser plumes. This has been seen before, but I suddenly realized how that can help determine the geysers' locations, and I thought Slashdot readers might be interested in the general method."
http://www.ciclops.org/view_media/36124/Tethys_Rev_164_Raw_Preview_1
That's no moon. It's a space station!
I'm a dreamer, the world is my playpen. But hey, I'm a serious person, I can't dream all the time.
by nerds... " I’ve written about Enceladus about thirty two bajillion times, because it’s fascinating, and photogenic as heck" given just how nerdy this is no doubt it will have fewer responses than more mainstream non nerdy articles on slashdot.
Users... the only thing keeping 1st level support from being the bottom feeders.
Icons of this. It shall be done.
Gorgeous, gorgeous.
You want to know how to help your kids? LEAVE THEM THE F*&K ALONE. --George Carlin
Here's your five minutes back. The balance of eternity is for people that understand how wondrous this is.
By the way, you are wrong about the "Slashdot whore" part, just so you know. Sites like "Bad Astronomy" qualify as being one of the main reasons Slashdot was created.
Seeing the images, running us through the thought process - lovely. More stories like this, please. It was fascinating and wonderful.
2) Unrelated, but what the hell are those things at lower left (and two of them crossing in upper-mid-to-upper-right)this pic from a more more sane 17000 km? Ridiculously long crater chains from ejecta, or something rolling/bouncing "downhill"? Seems weird that it could roll "downhill" through a crater without altering its path, so I'm leaning towards crater chains from ejecta, but they seem pretty wildly extended for crater chains, yet are too varied in direction to suggest faults. Where was this relative to the "tiger stripes"?
Do we have enough photos of Enceladus' surface (illuminated, from different angles) so that we can look at these locations and see what lies there? Now that could be interesting.
Have gnu, will travel.
This article has the least comments I've ever seen for an article on the homepage. Only 16 comments after 7+ hours. What's happening with Slashdot??
No, he CAN'T have his five minutes back - you know the rules, no refunds on Slashdot except through the complaints department.
"The Bad Astronomer" has been around long enough, and has enough credibility, that anyone who claims he's a karma whore is de-facto neither a nerd nor a geek and should gerroff our collective lawns.
Obvious Geometry is indeed Obvious. This guy, Euclid, wrote some of the Obvious Geometry down and used it as a teaching manual. Nobody had done that before. Everyone in his time knew the rules he was describing (Archimedes regarded them as insultingly simple), but few had understood the fundamentals (what was axiomatic, what was derivative) and absolutely nobody had thought of actually explaining things before. The result of him doing so caused the number of mathematicians and their skills to explode. The learning curve had become dramatically shallower.
This is really no different. Sure, it's basic but the learning curve of WHY it works, HOW it works and WHEN/WHERE it can be used is NOT common knowledge. This makes teaching the relationship of maths and astronomy a cakewalk. I have no objections to more people seeing why geometry and maths are relevant (a common complaint is that they aren't ever used anywhere, but that's because nobody explains why, yes, they are). I regard it as the sole opportunity for turning the world into people who can think for themselves.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
"The Bad Astronomer" has been around long enough, and has enough credibility, that...
...my 78yo dad sends me links to his articles. As for this article the explaination is easy to grasp, invariably the hardest part is spotting what is right under your nose and thinking "That's odd?".
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
The result of him doing so caused the number of mathematicians and their skills to explode.
I read that as "The result of him doing so caused the number of mathematicians and their skulls to explode."
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
So now that we know all this stuff the Bad Astronomer said, I want to lay down a challenge. I noticed the Bad Astronomer included no actual plume information. How tall ARE the plumes? How far away are they from each other? How did you calculate your figures? I won't be able to work on it until after my real work, but lets see if any enterprising Slashdot aficionado can come up with the info, preferably using math, not an online source. Don't make me break out my TI-86 and be the first to come up with the data!
A girl in my highschool back in 1988 was used voyager I or II photos (I can't recall which) to calculate the depth of craters on a couple of Jupiter's moons. Which is little different than what the article is describing, but it seems shadows have a lot more information encoded in them. This girl and I ended up winning the science fair and going on to the International science fair, where I felt a bit out of my league. She won a few awards. Apparently at that point no one had thought to do that up to that point. (for those interested, I wired up a photometer to an Apple II and wrote some software to automate variable star photometry, which measures the light from light sources through a telescope over time. It can be used to find the rotation of asteriods, or with a sensitive enough instrument, the change in light from a large planet orbiting a star, stuff like that.)
Had the Vikings invented geometry.....
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)