Something not quite that big once hit Mars and blew away it's atmosphere. The MOLA, (Mars Orbital Laser Altimeter) revealed the crater left behind from this unbelievable impact. Before it hit, Mars had an atmosphere and lots of liquid water similar to earth today. With the atmosphere gone, the water literally boiled away into space.
On the below picture, you can easily see where the impact occurred, and where Mars had it seas and oceans at one time. The lower the elevation, the darker blue, the higher the elevation, the more red. The deepest place on Mars today is where the asteroid hit.
So... such an event can really happen. The universe does not care and if it happened to earth, who - or what - in the universe would even notice?
Only us. But what a show it would be while it lasted. Don't bother taking photographs, there would be no one left to look at them.
Compared to a setback like this, Obama and all his co-conspirators are far less than a flea's fart in the wind.
It's all relative.
So don't worry... be happy.