BOSTON - WGBH-TV’s huge electronic screen that greets drivers on the Massachusetts Turnpike as they enter Boston will be blank for the rest of the summer.

The 30-by-45-foot screen is part of the station’s new $85 million headquarters. During the day, it shows images drawn from WGBH’s television or radio programming or images that reflect the public television station’s mission. At night, the screen shows an image of the evening sky.