The event horizon, or schwarzschild radius for a black hole with the mass of the Earth is 3 km. But according to http://hubblesite.org/reference_desk/faq/all.php.cat=exotic, objects would have to be as close as about 6.2 miles (10 km) to the black hole's center before they began spiraling in. Event horizon is 3km from the centre of the Black hole the mass of the sun, so if you are say 4 km away from the radius you should be able to escape being sucked into the black hole. But the distance according to the above website is 10 km. Why?