djr>That is indeed when the Earth's axis will be tilted the other way, relative to the stars. But the perhelion moves around too, and you haven't accounted for that. See "anomalistic year". Yow, the perihelion is *delayed* almost 5 min/orbit, while the solstice advances > 20 min, so anglicize(anomalisticyear-solaryear) gives 25 min, 7.1 sec, and canon(180.*days/%) gives 10319 orbits for a "full tilt". I thought perihelion precession was only detectable for Mercury.
4.09053820802342 second + 56 minute + 23 hour djr>I wonder, how accurately has the sidereal day been measured, Of course, everything past the 4.09 in the above figure is rubbish. djr>and how does it vary? Besides tidal slowdown, we have those Hawaiian volcanoes piling up inertial moment. Until someday they pile too high ...-( djr>My HP 48GX calculator does unit conversions: it seems to use the Bessel year, news to Webster, but not the Web djr> when converting years to days. I think most people want calendar year.
Suppose a large comet hit Mercury. Could the dust cloud shade Earth noticeably? Ice age theory 2: The solar system passes through occasional galactic dust clouds. --rwg PS, http://www.nature.com/news/2005/050117/full/433181a.html wants you to pay money for a story entitled Titan team claims just deserts as probe hits moon of creme brulee. I thought they said it was *wet*! It would be just like the British to make creme brulee from a mix. Conspiracy theory: the final 350 images were not lost, but are being suppressed because they show indignant blancmanges menacing the lander. "Hyperbole is the sinh qua non of exponents."