Asteroids are small rocky objects orbiting the Sun. Most of them are found in the asteroid belt between Mars and Jupiter, but some have orbits that bring them close to Earth. These asteroids are called near-Earth objects (NEOs).

Most NEOs are small, but a few are quite large. The largest NEO currently known is Apophis, which is about 320 meters in diameter. Apophis will pass by Earth in 2029 and 2036, but there is no chance it will hit our planet.

Some people worry that a large NEO could hit Earth and cause global devastation. However, this is extremely unlikely. In fact, no known NEO is large enough to cause global devastation. Even if an asteroid hit a large city, it would cause localized damage, not global extinction.

The Earth is constantly bombarded by asteroids, but most of them are small and harmless. In fact, the average person swallows more material from asteroids every year than they inhale from the air.

In the past 100 years, there have been only two known instances of small asteroids striking Earth: one in Tunguska, Russia in 1908 and one in Chelyabinsk, Russia in 2013. Both of these events caused localised damage, but no serious injuries or deaths.