The idea hit Al Gore one night at 3 A.M., and he sat bolt upright in bed: Let's send a satellite into space that would beam back sun-washed images of the whole Earth -- something more majestic than the tight shots seen on the Weather Channel, something that would show storm systems and forest fires and cloud formations in real time, a channel devoted to all Earth, all the time.

Later that morning, the Vice President jumped on the Internet, made some calculations and called his friends at the National Aeronautics and Space Administration. NASA scientists started designing the system. And today in a speech at the Massachusetts Institute of Technology, Mr. Gore shared his dream.

''As Socrates said 2,500 years ago, 'Man must rise above the earth to the top of the atmosphere and beyond, for only thus will he understand the earth in which he lives,' '' he said.

The high-definition video pictures would show the portion of Earth that is always drenched in sunlight, from the North Pole to the South, against the black backdrop of outer space. The Vice President hopes the images, which would be available by 2000 on television and the Internet, would increase earthlings' appreciation for the fragility of the planet and their place in the universe.