Near Earth objects

Imagine: One day, you are happily walking on a street, and the last thing you see is the sky getting dark. Why do you die?
Probably, there things above your head that can kill you. Those things are called "Near Earth Objects".

"Near Earth Objects. Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighborhood."

NASA

According to "Earth Impact Effects Program", an 7-meter-diameter asteroid can hit the Earth with energy of Little Boy, an atomic bomb dropped during Word War 2. NEOs hit the Earth everyday. However, since most of asteroids are not really big, they get broken during their way.

-Why should we care about it? 

-None of us will survive if struck by a NEO that is large enough to pass through the atmosphere.

- Why should we care, since we can do nothing because NEOs are far away from our reach and too many to destroy?

- Well, there is always something you can do. First, pray. In case praying doesn't work, there is a temporary solution. Spacecrafts can be sent to calculate and deflect the path of NEOs. However, there is no permanent solution. We are safe, for now.

"It’s simply a question of when, not if, a NEO collides with the Earth."

Professor Monica Grady