It’s a mere slip of the keys, but Mark Henderson has inadvertently relocated the surface of the earth to Mars in his recent write-up of the “aqueous sea” observed on the red planet by the European Mars Express spacecraft. Check out par 2 in his article Frozen sea…, where you will read of a “subterranean aquatic layer”. Pardon me, but isn’t “Terra” the name of our planet and thus subterranean refers to below the earth’s surface. Anyway, what’s wrong with “underground water”, rather than all this aquatic layer malarcky?