The holes around Phobos

This is actually one of the absolute cleverest subject lines I've ever come up with.  Skip down to the bottom if you want to know why.

In the meantime, however, I'm highlighting an article (one of several that has appeared since yesterday) about a determination of what likely caused the strange long rows of craters on the Martian moon Phobos.

Put real simply, they happened by this process:

Step 1:  Phobos gets hit by a large rock, though considerably smaller than Phobos.

Step 2:  The impact forms a primary crater; some of the debris generated by the impact escapes the weak gravity of Phobos and goes into orbit around Mars.

Step 3:  Some of the heavier debris doesn't escape Phobos and falls back down, making some smaller secondary craters.

Step 4:  A few orbits later, the debris re-encounters Phobos; and the resulting impact with the orbiting debris field creates the long row of craters, called sesquinary craters.

Cool, eh?

Here's a picture of what the article, and the research paper that inspired it, are describing.

(Oh yeah, about the subject. There's a short story called "The Holes Around Mars".  It's science fiction, though the scientific aspects aren't greatly accurate.  But Phobos is involved.)