Landsat: Continuing to Improve Everyday Life Spiders crawling over Landsat satellite photos of the earth in a loop. Of the 35,000 species of spiders described worldwide, only a handful are considered to be dangerous and only 27 are known to have caused human fatalities. The irrational fear of spiders is an apt trope for unfounded fear -in the colloquial sense, “paranoia”, which conditions racism, diffidence and the Hobbesian trap of violence.