What if an Asteroid hit the Earth

What is asteroids ? Where are they located ?

Asteroids are

Size of an asteroid is

What percentage of solar radiation that hits the Earth's atmosphere ever reaches the surface?

An asteroid of mass 2 xx 10^(-4) M_e , where M_e is the mass of the earth, revolves in a circular orbit around the sun at a distance that is twice earth's distance from the sun. Find the ratio of the kinetic energy of the asteroid to that of earth

The theory that dinosaurs were driven to extinction by the aftermath of a large asteroid impact on Earth was given by______.

An asteroid, headed directly toward Earth, has a speed of 12 km/s relative to the planet when the asteroid is 10 Earth radii from Earth's center. Neglecting the effects of Earth's atmosphere on the asteroid, find the asteroid's speed v_f when it reaches Earth's surface.