The day was April 9, 1965. A sold out crowd of 47,879 fans were greeted by the sign that said it all that day: "Welcome to the world's first indoor day baseball game."
The Astros versus Yankees exhibition game was a star-studded affair with President Lyndon Johnson and wife, Lady Bird, in the stands along with Texas Governor John Connally.
You can watch archive footage from the first game at the Astrodome in the video player above.
Fans quickly fell in love with the air conditioned dome, the giant scoreboard, its homerun spectacular and indoor fireworks.
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Even back then, traffic to the world's first domed stadium, dubbed "the eighth wonder of the world" was a mess. And at first, so was the lighting, thanks to translucent panels that made up the ceiling.
The glare from the sun was so bad, players routinely missed fly balls and resorted to sunglasses.
The Astros experimented with baseballs of different colors, including orange, yellow and red baseballs.
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A week later, the panels were painted white and the glare was gone. But the lack of light killed the grass and artificial AstroTurf was born.
Yankee legend Mickey Mantle had the first hit that historic day, a single and the first home run in the dome, but that day belonged to the Astros who won it 2-1.
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