From NASA.gov:
I overheard on NPR that Bill Nye was going to do a web series for NASA talking about the Juno mission. So I went to NASA’s website. What a turd, its down due to the whole budgety thing. Does anybody know anything about the web series? I would really like to watch. I like Bill Nye.
Nothing about the web series, but I really want to re-title your thread “the Shutdown is Nye!”
(as in “nigh”)
Here you go. No functioning government necessary.
I swear to Jeebus I Googled it like twenty times, and search Youtube. You are a genius, armedmonkey!
Yes, grasshopper, I am a true master of Google-Fu.
But seriously, I didn’t even know these things existed until your thread. I sincerely thank you for that. I love me some Nye, so I went looking.
Ok…now it’s question time!
I watched the one about trying to figure out what’s inside of Jupiter. They plan to have Juno orbit Jupiter and then measure the distance between Juno and Earth to plot it’s course around Jupiter. Why not send radio waves down to Jupiter and measure it’s height directly? Is it just because it’s gaseous? I assume that’s the reason, I just would have guessed there’d be an easier way then crunching all the numbers involved in mapping the orbit or a satellite around a planet by using Earth as a reference point. That’s a lot of moving objects. If we take a measurement now and another one a few seconds later, Earth, Juno and Jupiter have all moved and that all has to be taken into account. Don’t get me wrong, I’m a Math major (and was planning to be a physics major) so I’m no stranger to this, it’s just to bad they couldn’t fix at least some of these points.
It’s simple triangulation. Juno can measure its distance from Jupiter, but it can’t measure it’s exact location without two reference points. Without location measurements of location, measurements of distance are meaningless. Jupiter and Juno are obviously two points of the triangle, but you need another. That’s where Earth comes in.
I suspect you’re over thinking it. Don’t think calc - think trig.
A)How do airplanes figure their height? I just assumed they bounced a radio wave off the ground. They don’t need a third point if they just send it straight down…wait, that’s the confusion. I thought it was just measuring distance. I guess they’ll want location data too huh.
B)Jupiter has 67 moons, they can’t use one of them? I had a whole big post written out here with reasons for and against using Jupiter’s moons vs NASA, but I really don’t know the answer here.
My rusty brain reveals three types of height measurements for planes:
Barometric
Radar Altimeter
GPS
I’m sure there are others, but my Google-fu is in hiatus.
They could conceivably use the moons, but why? Juno has to communicate with Earth to send the data back anyway, so use that signal to measure one side of the triangle.
However, it occurs to me that since we are dealing with three dimensional space, they probably need a fourth point to nail down the location. Three points works fine in two dimensions, but you mentioned airplanes, and they need four points, too. Altitude takes two points (ground and plane), distance to destination would be the third, but a fourth is necessary otherwise the pilot wouldn’t know if he was North, South, East, or West of where he was going.
Location is obviously important if the idea is to map Jupiter’s surface (if it even has one). They could use one of the moons there as another reference point, but moons aren’t fixed - they’re in orbit. You can correct for that, but again, why make it hard? If it was me, I would use the sun because it’s a fixed point in regards to these equations. Four points in a three dimensional space is probably the minimum.