It is highly unlikely that a major asteroid will hit Earth and make a lot of damage. Although like in Russia recently an asteroide hit this major doomsday scenario is just not realistic. There are more important things to worry about: Unemployment benefits for all and jobs and education for all. Reduce violent crime. Fight scams on the Internet. Although the subject of exloring space is important there are also other important things that government must deal with.
One should be very paranoid to believe a gian rock would hit Earth and destroy it all. The science on this is not very precise and clearly it is a subject that has to be explored in detail. However, it is hard to say whether or not an impact will occur. One might be wasting a lot of time trying to predict something which is virtually impossible to predict.
It is not really something to be afraid of. There are many things on Earth to be afraid of. There is no reason to fear something from outer space. It is also highly unlikely that our planet will be visited by Aliens because the distances are so big in the universe. Therefore an impact of a large rock is also very unlikely.
It is a difficult subject to deal with because it is unclear what the odds of an impact is. However, it is really not very likely that Earth will be hit by a big rock. There are many movies about disasters. It is a good subject for entertainment but that does not mean it is actually going to happen.
The spaces of this universe are so big that most planets and large objects in space will not hit each other. It seems to have been designed that way in order to prevent planets from colliding. However, it is a very interesting scientific subject that is hard to deal with in a totally objective and empirical way. However, it is fair to say that the odds of a major disaster is slim at best since Earth is very far from those dangerous objects that might hit it. It will be interesting to see what science will find out about this subject during the next couple of years. Probably in the next couple of years Hollywood will make many disaster movies but that does not mean that these disasters will actually take place.