The Astrodome and Baseball Under Glass

When the Houston Astrodome opened on April 9, 1965, a tour guide would sit visitors down facing the playing field and say, "Welcome to the Astrodome. You are now sitting in the largest room in the world." Then she would pause and let it sink in.

The building was the vision of Roy Hofheinz, a former Houston mayor and county judge who had secured an expansion franchise for Houston in 1960 by promising National League owners something nobody had ever built. An enclosed, air-conditioned baseball stadium. Hofheinz got the idea after visiting the Roman Colosseum with his wife and wondering why nobody had put a roof on a stadium since. The answer, in Houston's oppressive heat and humidity, was obvious. If you could play baseball indoors, people would come.

Construction began in 1963. The dome was 710 feet in diameter and 208 feet high at its apex. The playing field sat 25 feet below the surrounding parking lot. The original roof was made of 4,596 clear Lucite panels designed to let sunlight in so grass could grow. The stadium seated 42,217 and was air-conditioned to 74 degrees. It had luxury boxes, the first in any major sports venue. It had a four-story scoreboard in right field that exploded with animations after Astros home runs. It had restaurants, upholstered seats, and concessions that were, by the standards of 1965 ballparks, absurdly upscale.

Hofheinz lived there. He built a seven-story private apartment adjacent to the right field bleachers, designed by a former Disney artist, that included a bowling alley, a shooting gallery, a chapel, a miniature golf course, a beauty parlor, and a puppet theater for his grandchildren.

The building was immediately nicknamed the "Eighth Wonder of the World." In its first year, more than 400,000 people paid $1 each just to tour the inside. The U.S. Commerce Department ranked it the third most popular man-made attraction in America, behind the Golden Gate Bridge and Mount Rushmore.

Then the problems started. The Lucite panels let in sunlight, but the sunlight created a glare that made fly balls invisible. In the first exhibition game, Astros outfielder Jimmy Wynn lost a routine fly in the glare, turning it into a three-run inside-the-park home run. Hofheinz ordered the panels painted over. The glare disappeared. The grass died.

For most of the 1965 season, the Astros played on dead grass that was painted green. The solution came from Monsanto Chemical Company, which had developed a synthetic carpet of interlaced nylon fibers called ChemGrass. Hofheinz met with Monsanto, negotiated to have the product installed free of charge as a testbed, and renamed it AstroTurf. The first major league game on artificial turf was played in the Astrodome on April 18, 1966.

AstroTurf changed baseball. Over the next two decades, it spread to stadiums across the country, altering how the game was played. Ground balls skipped faster on the hard surface. Outfielders played deeper. Speed became more valuable. The turf also caused injuries, particularly to players' knees and joints, and it was widely hated by athletes. By the 1990s, teams were ripping it out and returning to natural grass. But for 30 years, AstroTurf was the surface of modern baseball, and it existed because the grass died inside a dome in Houston.

Hofheinz suffered a stroke in 1970 and lost control of the franchise to creditors. The Astros played in the Dome through the 1999 season before moving to what is now Minute Maid Park. The Astrodome was declared non-compliant with fire codes in 2008 and was listed on the National Register of Historic Places in 2014. As of 2025, it still stands, closed to the public, used as a storage facility for the surrounding NRG Park complex. Various redevelopment plans have been proposed and abandoned. Nobody has figured out what to do with the Eighth Wonder of the World, and nobody can bring themselves to tear it down.