Lynda, not sure what the maximun image size for a jpeg is, but on the sute NASA has high resolution TIF files - yes they are massive but probably overcome the jpeg limitation. Click on one of the images and you will see the button below for the TIF file... Looks like each file is around 1GB those can definitely be opened in Photoshop. But take a while to download
Hope this helps
If it is 68000 pixels tall, then it can't be encoded as JPEG, even in a TIFF wrapper.
(JPEG limit is 65535 pixels)
I was afraid of that (having to download the 500mb - 1GB file. Sounds like fun =>
I will check that out, thanks for the link.
A quick check with OS X 10.6.8 reveals that the PTIF file "M150368601_p.tif" can be opened by at least: