A team of researchers from the Leibniz Institute for Astrophysics in Potsdam, Germany, have used data from the Radial Velocity Experiment (RAVE) survey to work out the exit velocity required to leave our home galaxy. By analyzing the motion of 90 high-velocity stars and using a series of complex theoretical models of the galaxy's mass calculate, they were able to calculate the speed at which objects can exit the Milky Way.
Their results suggest that a spaceship would need to hit 537 kilometres per second—that's 1.2 million miles per hour or 0.2 percent of the speed of light—to escape the gravitational pull of our galaxy. For context, a rocket needs to reach 11.2 kilometres per second to escape Earth's gravity.
"I know it's a crazy idea, but if you had lots of matter and lots of antimatter, you could power a spaceship out of the galaxy."
Image by GSFC