The body page used to spin every body about its pole at 0.08 radians a second, under a light at
(4, 3, 5) whatever the date. A body with IAU elements is now drawn as it is at the map's clock,
using the same pole, prime meridian and map convention as the system view. It is shown pole up
under a Sun held at the light's old azimuth, so the camera still opens on the day side. The Sun's
height above the equator is the real one, and so is the face it lights. The clock's rate now
turns the page too: at 1 h/s Earth's sub-solar point moved 15.17 degrees in the 1.012 h of sky
one wall second carried. What the page gives up is the stars, which do not turn with the body.
bodyPageView in src/app/shared/rendering/body-orientation.ts takes the Sun's direction from where
the body is: a planet's own mean elements, a moon's planet's place plus its own offset. It sets
the sphere's rotation and the light's direction. Exoplanets, Eris, Haumea and Makemake keep the
old slow turn and light.
Saturn's rings now lie flat in its equator, the page's horizontal. They used to lean 17 degrees,
which put them out of the plane they orbit in.
Measured:
- Live app, clock pinned to 2025-06-01 12:00 UTC: the Sun stands over 0.433 W, 22.125 N on
Earth's page, the same point as on its sphere in the system view.
- Unit test, raycast on the page's own sphere: Earth one light-time earlier is 0.09 degrees from
Horizons' sub-solar longitude. Its latitude, put on the flattened Earth, is within 0.03.
- The Moon's sub-solar point is within 0.004 of Horizons'.
Three mutants each fail their named test: a moon lit as if it had no planet; the Sun not held at
the page's azimuth; the body left in the ICRF instead of the page's frame.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
SenrokaiandClaude Opus 5.5
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