Post by Chicago Astronomer - Astro Joe on Dec 28, 2010 0:56:58 GMT -6
Good Vid of Jupiter from an Earthbound scope
Taken in September from Barbados with this interesting explanation:
"The movie was assembled from a ‘map’ of Jupiter which Peach assembled from his best shots, and digitally ‘projected’ them onto an oblate spheroid to obtain a full 360-degree rotation. The projection of the map is smoothly uniform in illumination across the whole longitudinal (east-west) swath, so while the polar regions look normally limb-darkened, the edges of the planet near the equator must necessarily be exhibited without limb-darkening, which any single shot would typically reveal. Hence the reason for the apparent ‘pixely-cropped’ look of the equatorial limb. (in fact, it’s possible to reintroduce an artifical mask that mimicks limb-darkening for the equatorial limb, but doing that is difficult to pull off and would actually introduce an artificial artifact that would be less ‘real’ than the map composed of a composite of many images).
It’s also why the movie has no ‘wobble’, since all the projections are perfectly registered in the process. Full rotation movies with such high uniform resolution would be very difficult if not impossible to obtain in a single night’s observing on the ground with Jupiter anywhere high enough in elevation above the horizon to keep the resolution uniformly high: even it’s swift 8-hour period can’t be squeezed into a single nominal 10-hour observing night (‘astronomically dark’ without twilight) with Jupiter near opposition. Peach reports he obtained his results when Jupiter climbed above 75-degrees above the horizon, so that there were at most only a few hours available to obtain high-res shots on any given night.
The detail incredible and some great imaging from ground based consumer grade equipment. To this eye, the series of black dots look a lot like impacts from unknown objects.
Some say that the Southern Equatorial Band is coming back, but I dunno. But I have never observed the Great Red Spot as dark as I have observed it this past season.