The Day the Sky Exploded

Atomic rocket XZ is set for the first flight to the moon. Although it is an international effort, an American is chosen for the first flight. The launch goes well, but when he blasts out of orbit something goes wrong. He's forced to abort the mission. He returns safely when his capsule plunges back to earth; however, his atomic rocket carries on out of control on into space.
Sometime later, animals all over the planet begin to act strangely and they seek shelter. Soon scientists detect something coming towards earth. It turns out that the atomic rocket has exploded and sent an asteroid on a collision course with the earth. Vast evacuations have to take place as the asteroid will impact the earth in a matter of days.
It seems hopeless, but then a scientists figures that if the US and the Soviets fire all their nuclear missiles at the asteroid, it will be destroyed, thus saving the earth. Does the plan work? That would be telling.
This 1958 Italian film was originally known as La Morte viene dallo spazio. It was released on the US in 1961 where it was also known as Death Comes from Space and Death From Outer Space.