Why does a rocket have to go 25,000 mph (about 40,000 kilometers per hour) to escape Earth? – Bo H., age 10, Durham, New Hampshire There’s a reason why a rocket has to go so fast to escape Earth.

There’s a reason why a rocket has to go so fast to escape Earth. It’s about gravity – something all of us experience every moment of every day. A SpaceX Falcon 9 rocket with its Crew Dragon capsule ...