About 12 million people live along the line of totality, a 70-mile-wide (113 kilometers) path from Oregon to South Carolina where the moon will block out the sun's light for a few minutes during the eclipse. Close to 200 million others live within a day's drive to that path, and it's going to cause some of the worst traffic jams in American history, Martin Knopp, an official with the Federal Highway Administration at the U.S. Department of Transportation, said during the briefing.
But the entire continental U.S. and other areas nearby will be able to see at least a partial eclipse. Anyone who isn't watching the total (or partial) eclipse in person will have plenty of options to watch the eclipse live online. [Total Solar Eclipse 2017: Path, Viewing Maps and Photo Guide]
NASA will broadcast live eclipse footage from 11 space-based telescopes — including two of the National Oceanic and Atmospheric Administration's Earth-monitoring satellites — on NASA TV and online on Aug. 21. NASA's networks alone can bring in billions of viewers, Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate here in Washington, said during the briefing.
And that's not all – other groups will be providing more perspectives of the eclipse. Researchers at Montana State University in Bozeman, Montana, plan to send dozens of high-altitude balloons into the sky on Aug. 21 to observe the eclipse with high-definition cameras and broadcast their images live online as well. The Slooh Community Observatory will also share live footage of the eclipse from ground-based telescopes.
Thanks to social media and the internet, there are plenty of ways to see the eclipse, and millions of people will be able to experience it firsthand. "My personal feeling is that it will be the most watched, but I can't prove that scientifically," Zurbuchen said.
"The assertion is really hard to prove, because we don't have really hard numbers on any [previous eclipses]. I think it's definitely one of the top candidates, if not the most- watched eclipse. If we take all the vantage points, all the assets together, and all the channels we're going to put out, it's going to be hard to beat, frankly."