City Killing Asteroids: NASA Scientist Warns of Unstoppable Threats to Earth

Asteroids are large rocks orbiting the Sun. Most remain in the asteroid belt between Mars and Jupiter. Some, however, pass near Earth’s orbit. When they are large enough to cause regional devastation but remain undetected until too late, scientists call them City Killing Asteroids. These space rocks are not massive enough to end global civilisation like the one that likely wiped out the dinosaurs, but they would be powerful enough to destroy entire cities or large regions on impact.