[jimt]

You don't find fractal topography like that on rivers and you don't find 5000-kilometer rivers on Mars, Earth, or anywhere else that I know of.

Try this site.

http://www.rev.net/~aloe/river/

It lists the Nile as 6484 kilometers to the surce of the farthest tributary.

Perhaps a little more research before postulating electrical arc craters?

[medved]

I'm not into nitpicking; take a look at the images of Valle Marineris and see if you can't tell the difference.