Astroturf, a hard, synthetic alternative to grass, became widespread in the NFL in the 1970s, 80s, and 90s. When the Houston Astrodome, known as the “Eighth Wonder of the World,” opened in 1965 as the home to the Oilers, a problem emerged: the grass didn’t grow. So fake grass, “Astroturf,” was used instead. It was cheaper than grass, as it required less upkeep, and other stadiums followed. By the 1990s, about half of NFL stadiums used artificial turf. Due to the harder, springier surface, Astroturf enabled players to run faster than on grass, and speed became more highly valued. The downsides, though, proved costly. Because Astroturf was so hard underneath, it caused many devastating injuries, especially to the knees, and shortened if not ruined many careers. Eventually, FieldTurf, a softer and safer synthetic grass, emerged as an alternative, and Astroturf fields went extinct.