Its inhabitants, two alien observers, are watching the riot on Maple Street while using a device to manipulate the neighborhood's power.

As an alien observer, you'd wonder who's the president of the USA.

"How can a Richter Scale of Culture rating indicate the presence of alien observers?"

"Maybe it's an alien observer telling us the secrets of the universe!"

So the Seti had collected an array of alien observers to gloat over, had they?

In the absence of an apparent natural cause, alien observers might infer the existence of a terrestrial civilization.

As the alien observers view events several times over the same footage is played forward and backward.

Heywood Floyd had watched the geopolitical changes from his vantage point on Pasteur, almost as if he was an alien observer himself.

To avoid capture by the Shalka, this Doctor tries to act as if he is a detached alien observer.

The plot focuses on several humans whose lives are changed by the aliens, and an alien observer investigating the morality of these changes.