Clouds will sometimes play tricks on you. Meghan Searl (Member 65,620) saw what looks like a distinct gap between clouds above San Juan, Puerto Rico, but it is nothing of the sort.

What we’re seeing here is actually one cloud casting its shadow onto another. The thinner layer of cloud in the upper right of the image is visible where the sunlight shines onto it but doesn’t show up in shadow even though it extends through that part of the sky too.

And there’s another bit of cloudy deception at play here. It looks as though the Cumulus cloud, in the lower left of the image, is casting its shadow up to a higher cloud beyond. But, in fact, what we’re seeing is a very tall Cumulus, known as Cumulus congestus, that is casting a shadow _downwards _onto a thin layer of cloud – likely Altostratus – beneath its summit.

Here are three cloudspotting lessons to bear in mind: thin clouds don’t show up when they’re in shadow; the Sun almost always shines downwards and so shadows in the sky tend to be pointing down; the clouds rather like to befuddle you.