Orbital ATK
The Antares rocket is loaded onto the launch pad October 14, before launch.
It's a very good night to be a rocket geek on the East Coast.
As Maddie Stone highlighted over at Gizmodo, an Antares rocket launch at 7:40 p.m. just off the coast of Maryland should be visible across much of the mid-Atlantic - even for a few moments from places as far from the launch site as South Carolina, Pittsburgh, and Boston. The rocket will be on its way to the International Space Station with supplies, after delays due to Hurricane Nicole and a technical difficulty.
Here's a map of the regions that should be able to view the launch, as long as it's a clear night:
Orbital ATK
The farther from the center, the lower it will appear over the horizon. So unless you live in a flat, treeless plain you may want to get on top of something tall for ideal viewing.
Here's when the rocket should first become visible from each area:
Orbital ATK
The best views should be from areas fairly close to the launch site in Maryland, like Baltimore, Norfolk, Virginia, and Philadelphia. But New York City, Harrisburg, and Raleigh should get a decent view of the action as well.
Of course, it won't look like a big machine riding a column of fire unless you're very close. Expect it to look more like a glowing streak across the sky above the horizon.