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CelestiaProject / Celestia

Real-time 3D visualization of space.
https://celestiaproject.space
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Is Celestia's accuracy within desired bounds? #23

Open fgeorgatos opened 7 years ago

fgeorgatos commented 7 years ago

Hi,

if you recall, I had reported more than a dozen years ago the following issue, ie. tracking Xerxes eclipse' shadow via Celestia should cast a plausible totality path: https://www.quora.com/What-is-the-most-interesting-bug-you-have-ever-solved-in-a-computer-program/answer/Eur-Ing-Fotis-Georgatos

However, I had a look at it again and it makes me doubt the accuracy - your comments?!

thanks for Celestia! F.

CelestiaProject commented 7 years ago

@fgeorgatos Hi. Please provide a cel:// URL for the event, which ephemeris he's using, and exactly what the timing problem seems to be. The accuracy of the Earth's orbital path and rotational speed in Celestia have undergone many improvements, but the default ephemerides provided in Celestia aren't as accurate as many professional epmemerides, especially over long periods of time. When high precision is required, Celestia allows the use of several different JPL ephemerides and NASA SPICE orbits. Instructions for how to use the ones from JPL are available at https://en.wikibooks.org/wiki/Celestia/JPL_Ephemerides

CelestiaProject commented 6 years ago

Closed due to inactivity.

fgeorgatos commented 6 years ago

Hi,

apologies, I hadn't seen the URL request, here it is: cel://Follow/Sol:Earth/-479-10-02T14:29:03.58957?x=GPnqpYdeUf///////////w&y=00pztYE6/////////////w&z=SEf71VtMhw&ow=0.897901&ox=-0.00160906&oy=0.440194&oz=-0.000684459&select=Sol:Earth&fov=23.3578&ts=-100&ltd=0&p=0&rf=313239&lm=0&tsrc=0&ver=3

If you check carefully, you'll notice that totality path of said eclipse is supposed to transit Gibraltar, which is not the case with v1.6.1