[HN Gopher] The Planets Today
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The Planets Today
Author : hyperific
Score : 77 points
Date : 2024-07-07 09:33 UTC (4 days ago)
(HTM) web link (www.theplanetstoday.com)
(TXT) w3m dump (www.theplanetstoday.com)
| classified wrote:
| Sol and Luna. Nice to see sensible names for these.
| dabluecaboose wrote:
| Sol and Luna are technically "incorrect" names for The Sun and
| The Moon, as per the IAU. (Notably, so is "Terra" for Earth.
| Earth is Earth, it already has a proper name)
|
| That is not to say I think they're un-sensible. I think it
| would be a great idea for the IAU to adopt them, as "Sun" and
| "Moon" are already generic terms from the reference of other
| planets/solar systems.
| findthewords wrote:
| IAU is not a sensible organization. See: Pluto and the dwarf
| planet category.
| dougdimmadome wrote:
| I like this. It really helps illustrate that how long it takes to
| get to Mars can vary hugely depending on when you leave Earth.
|
| My kids learned in school (during the 5 minutes of the year they
| spent talking about the solar system) that Venus is closer to
| Earth than Mars, but I had to use a diagram like this to explain
| that that's only _sometimes_ true
|
| kind of limiting that you can only go back and forward in time
| one month though. I would love a slider, a play button
| vundercind wrote:
| The free (FOSS, I believe) program Celestia is _excellent_ for
| showing kids that kind of thing.
|
| It's also lua-scriptable. I once created a "tour of the solar
| system" script that worked like a presentation (hit a button to
| advance to the next view) for my wife to use in her classroom,
| in an afternoon, never having scripted the program _or written
| Lua_ before. Did a top-down view with orbital tracks, zoomed to
| planets, did side-by-side size comparisons, all kinds of stuff.
| Not hard to use, very cool. Or you can just click around the UI
| and use keyboard shortcuts to demonstrate quite a bit of stuff.
| VagabundoP wrote:
| Its a great site. Really enjoyed playing with that.
|
| Now back to work.. :(
| dougdimmadome wrote:
| Though it doesn't show _today_ , this 3D model of the solar
| system is great
|
| https://codepen.io/juliangarnier/pen/krNqZO
| buggythebug wrote:
| Moon not Luna
| robofanatic wrote:
| The website design reminds me of my initial forays into website
| creation in the early 2000s using Dreamweaver.
| PopAlongKid wrote:
| Don't miss the button in the lower right to switch between
| desktop and mobile view, I almost did.
|
| "If you have our desktop version enabled on your computer, then
| the application shown above plots the position of the Earth and
| planets using data from this NASA's JPL website and is accurate
| between 3000 BCE and 3000 CE. If you have our mobile version
| enabled then we'll be showing you a simpler view of the solar
| system showing you the current planetary positions with the
| option of moving up to 30 days forwards or backwards."
| throwup238 wrote:
| 970 years from now someone is going to get rich selling an
| entire series of books about the upcoming apocalypse, predicted
| by the ancient NASA* calendar suddenly ending.
|
| * which will most likely be interpreted as a fertility cult
| because of all the phallic monuments.
| mongoosled wrote:
| This all but confirms that the Mayans had a robust space
| program going.
| throwup238 wrote:
| It's well known that there's an undiscovered functional
| Mayan space ship under Central Park:
| https://futurama.fandom.com/wiki/A_Farewell_to_Arms
| the_arun wrote:
| Also click on "Luna" on the bottom left to see a view of plants
| SoftTalker wrote:
| The orbits look perfectly circular. Is this a simplification, or
| are the elipses so mild that they look like circles at that
| scale?
| o87587586 wrote:
| It must be a simplification, for example Pluto's orbit is so
| eccentric that it's sometimes closer than Neptune
| dav_Oz wrote:
| Except for Mercury (eccentricity[0]: 0.2056) and the displayed
| transneptunian objects Eris (0.4407(!)), Pluto (0.2488), Haumea
| (0.1887) and Makemake (0.1559) all other planets (including the
| dwarf planet Ceres (0.0758)) are pretty accurate.
|
| Current orbital eccentricites for our plantes in ascending
| order:
|
| [0.00002 (Triton)]
|
| 0.0068 (Venus)
|
| 0.0086 (Neptune)
|
| 0.0167 (Earth)
|
| 0.0472 (Uranus)
|
| 0.0541 (Saturn)
|
| 0.0934 (Mars)
|
| [0.9951 (parabolic) (Comet Hale-Bopp)]
|
| So, the planets eccentricities (except for Mercury) are within
| one order of magnitude (0.01 and 0.1) nearly circular.
|
| [0]https://en.wikipedia.org/wiki/Orbital_eccentricity
| yardshop wrote:
| Click "To Scale View" in the upper left, then click on the
| concentric blue circles in the upper right of the main diagram
| to show inner planets, outer planets, or all planetoids
| including Eris.
|
| Also check out the Geocentric view for the earthbound
| perspective.
| moffkalast wrote:
| An honorable mention: https://celestiaproject.space
|
| This but in 3D and adjustable for any date. Plus lots of fun
| stuff like popular culture sci fi spacecraft.
| amriksohata wrote:
| wow now i understand the mandala representation in hindu
| cosmoology, the movements of the planets and the whole cosmos in
| lines of their paths
| notarealllama wrote:
| Tangentally, I came across this preprint today about sensible
| definitions for planets, as IAU doesn't actually call exoplanets
| "planets", and there's some unclarity re hydrostatic equilibrium
| ("how round") and especially the "clearing the path" / orbital
| dominance
|
| Quantitative Criteria for Defining Planets (UCLA)
| https://arxiv.org/abs/2407.07590
| dakiol wrote:
| I've seen so many times this 2D representation of the solar
| system and I felt somehow shocked when I saw a Youtube video
| supposedly showing how the planets actually orbit around the sun,
| and how the sun orbits the center of our galaxy. Basically, the
| sun is moving and the planets orbiting around it form some sort
| of vortex. If you look at the whole thing as if you were in front
| of the vortex (or behind), you would see the 2D representation.
|
| I don't know either if that's what happens in reality but this 2D
| representation is getting old I guess.
| jayrot wrote:
| I've seen that too when it was making the rounds. It's
| certainly interesting in that it opens your mind to the concept
| of reference frames. That said, I don't think the 2D
| representation is really all that inaccurate (and certainly
| that "vortex" animation isn't particularly MORE accurate
| either).
|
| That's the thing about reference frames. There is no absolute
| and there can be multiple that are equally valid. Frankly,
| using the sun as our reference frame makes perfect sense to me.
|
| When you're trying to visualize a car trip on a map from one
| city to another, is it really useful to visualize the car, the
| city, and the planet all spinning around, moving through space
| in the same kind of vortex?
| mmiyer wrote:
| It depends on your frame of reference - that video is true for
| a frame of reference which is the center of the galaxy. This
| representation is with the sun as the frame of reference. From
| that point of view it is the galaxy that is moving with respect
| to the sun and the planets.
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