No 18, credited to "NASA's Terra Satellite at 11.39 GMT Thursday April 15, 2010" is actually a processed composite of two Terra images in the MODIS RAPID RESPONSE raw image archive, taken in succession at 11:35 and 11:40. These images are in digital form and processed in various ways, so I don't mean to imply any shenanigans. The
NASA image gallery has the processed single Terra image of 11:35, and another processed Aqua image of 13:35.
I like to peruse the raw images ( which I learned of on this forum! ) because you can get the oversized higher resolution images and see more detail. Here's the 500m pixel size version of the 11:35 Terra image.
