Was there cilization on Mars in the past? Perhaps even today? There are a good deal of conspiracy theories out there that are just ridiculous like chemtrails and fluoride in our water killing us, but some have a grain of possibility. Why couldn't Mars have been inhabited? Hell, we couldn't find the largest structure in the world that was sitting in Guatemala until the 20th century! Imagine what weather and conditions could have done over thousands or millions of years?
Here's a site that discusses an anomaly on Mars that might point to civilization.
