Polar Asterisms

Have you ever seen the North star, Polaris? It’s decently bright and very close to the North celestial pole.  Lining up with the rotation axis of the Earth, the North celestial pole is the point in the sky that never moves, day or night.  If you know how to find Polaris, it becomes easy to find the cardinal directions and navigate by the stars. And finding it simply requires finding the big dipper, a bright and easily recognizable object.  The same rules apply in the southern hemisphere.  But even though there is no southern star, there is another fantastic object in the South that can guide you to the...

White Fingers on Mars

What do you think made the bright features in the picture below? Was it a deep layer of rock underneath sand that was swept away by wind? Or maybe it was salt left over from the drying of an ancient lake? Or perhaps even ash left over by an ancient volcano.  One of the answers is correct, and not the one I was hoping for. I wish it was from an ancient lakebed, oh what the salt deposits could teach us.  But alas, it is only volcanic ash.  So as true scientists, we follow what the data tells us, and learn...