When the moment comes, the object " which turns out to be a huge, translucent sphere " slows down and lands. Helen happens to be there, and walks up to the sphere just as an amorphous being is exiting. Just as Helen is about to shake hands with the being, a nervous soldier and/or cop shoots it.
At Walter Reed, the being sheds its pale, blubbery outer coating and turns into Klaatu (Keanu Reeves, "Street Kings," "The Lake House"). Klaatu wants to be taken to our leaders, but since he's in the good old U.S. of A., he's under the jurisdiction of Secretary of Defense Regina Jackson (Kathy Bates, "The Family That Preys," "Fred Claus"), who doesn't want him going anywhere. She takes the default military position that Klaatu is there to initiate some sort of invasion, while Helen senses that he represents a more benevolent purpose.
Klaatu escapes under his own steam, but due to his gunshot wound, he needs Helen to bring him part of his cocoon, which heals all physical maladies. While he can master English and Mandarin, and make cars drive themselves by touching them, Klaatu can't actually drive, so he needs Helen, accompanied by Jacob, to act as his chauffeur.
As they cruise from place to place, Helen slowly discovers the true purpose of Klaatu's visit: It seems humans are blowing it as far as maintaining the Earth, and a group of intergalactic civilizations have sent him to forcibly evict us from the premises.
As Helen and Jacob drive around with the unemotional Klaatu (the perfect role for Reeves, who's always best when required to keep his face as still as possible), they try to convince him that while humanity is in many ways a diseased pile of dog-flop, we also have some endearing qualities. Not many, but maybe just enough for Klaatu to spare our sorry lives for a while longer.
While there are some logical gaps and forced sentimental moments, "The Day the Earth Stood Still" is pretty good. Director Scott Derrickson ("The Exorcism of Emily Rose") makes good use of special effects while avoiding the kiss-of-death-overuse-of-CGI-at-the-expense-of-good-storytelling mistake to which so many others fall victim. As the alien, Reeves projects the correct amount of awkward emotional void (again, his forte), and Connelly manages to anchor the human side without emoting her way into melodrama.
On the minus side, one gets the feeling that young Smith's casting was the product of Hollywood nepotism. Unfortunately, the kid displays the emotional range of a pencil sharpener, and defeats his character's purpose in the narrative by being more annoying than sympathetic.
Overall, "The Day the Earth Stood Still" is worth seeing not so much for its message or performers, but the apocalyptic tension created in the pacing and overall production.