Asteroid
To dream of an asteroid coming towards the earth represents an potential problem with the ability to devastate goals, bring disappointment, or sabotage current efforts. An unavoidable disaster or embarrassment. Something that could make you feel like you never get to do what you wanted. It could also reflect situations that totally destroy your optimism or sense of balance you've reached.
If an asteroid hits the earth then it may represent goals or ideals that have been compromised.
Example: A man dreamed of an asteroid heading towards the earth. In real life he was telling friends about a vacation he was going to take, but secretly began to realize that he may not have enough money to do it. The asteroid reflected his feelings about friends potentially losing respect for him if they found out the truth.
Example 2: A man dreamed of seeing an asteroid entering the Earth's atmosphere. In waking life he had forgotten to take medication which he needed daily and it caused serious scary complications. He feared death due to the oversight.
*Please See Meteors