Asteroid

Asteroids are small rocky bodies that never came together in the early days of the Solar System to form planets. They now lie between orbits of Mars and Jupiter called the asteroid belt.Meteorites - Blast Off Into Space
If the asteroid hits on land, there would be a huge amount of dust thrown up into the atmosphere. If it hits in water, then there would be an increase in water vapor in the atmosphere. This would result in an increase in rain resulting in landslides and mudslides.
Regionally there might be earthquakes, hurricanes and tsunamis due to the increase in kinetic energy. If the asteroid is large enough, these could be global in impact.
==Asteroid belt==
The asteroid belt is a big highway in a circle around the Sun.
Asteroids can be a few feet to several hundred miles wide. The belt probably contains at least 40,000 asteroids that are more than 0.5 miles across.
If an asteroid is captured by the gravitational pull of a planet, the asteroid can be pulled out of the belt and go into orbit as a moon around the planet that pulled on it.
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