It took years to bring to the screen on account on nobody really wanting to be in it, but Alfonso Cuaron was finally successful in making Gravity. And now that film has a trailer. George Clooney and Sandra Bullock star as an astronaut and a scientist left stranded when their spacewalk goes awry. Hurtling out of control in their spacesuits, the pair cling to one another while searching for a way to contact Earth. Luckily for them, there is no such thing as space sharks.