Mars is In

Mars at the moment is "in" so we ought to take a look at this review of Robert A. Heinlein's science fiction book Stranger in a Strange Land about an earth child born and raised on Mars, who is returned to Earth 25 years after the departure of the initial Martian visitors.

If you do not know what GROK means, you will if you go the above link. The word was coined by Heinlein.
Do you GROK?!