I need images that ideally are minimum 300dpi and at least 1000px in one or both dimensions. I'm especially looking for oblique angles of the Earth from orbit showing the blue glow of the atmosphere, and some I've also seen with the Moon hovering just above the glow. I'm looking for just the Earth and/or Moon; that is, nothing man-made in the picture. I'm also aware of some images that seem to show either a solar eclipse shadow or a line where day becomes night on the Earth. I know there are a number of these kinds of images floating around; unfortunately, these seem to be especially hard to find now. Maybe I'm not using the right search terms (e.g. earth atmosphere moon). I have no idea which mission(s) might have taken the images, so I can't specify this in a search.
I've found a few sites that have long lists of the images they have, but no thumbnails (so I'll be ready to retire by the time I go through them all!). Most of the NASA image sites seem to have only a select few images to offer, and many of them only 640x480px. I would prefer larger or else my images will look very pixelated. I've even looked through some of the paying photo sites but haven't found any of this particular kind of image. NASA makes reference to some image labs that will do prints and scans, although I only see one listed. I'm not looking for a hardcopy, but a digital format. And it's very disappointing to think that hires images that used to be freely available might now be available only commercially.
I'm hoping someone here can help me find a source of these kinds of images, preferably free as my budget is pretty flat. Thanks in advance for any suggestions or links that anyone can share.
