Alien

Former DNI John Ratcliffe explained that such "sightings" are "talking about objects... that frankly engage in actions that are difficult to explain."

The series, which the whole family can watch together, is an inventive mix of sci-fi, adventure, suspense, teen romance and revenge-of-the-nerds comedy.

Many compounds that can possibly be found in the atmospheres in other planets can often only be made through industry.

Lightsail technology could allow humanity to achieve interstellar travel • Modern “Noah’s Ark” could help save, reconstruct life on Earth.

Though detecting radio signals from space happens regularly, they almost always have a mundane origin. But this signal's direction of origin and frequency changes have scientists excited.

With apologies to any space aliens who might be reading this, some close encounters are definitely better than others.

This "Galactic Federation" has supposedly been in contact with Israel and the US for years, but are keeping themselves a secret to prevent hysteria until humanity is ready.

To offer proof, the group shared a photo of a masked artist constructing one of the monolith structures, with the caption "you mean it wasn't aliens?!"

In the Kubrick movie, an alien monolith is a recurring symbol that appears to play a role in the development of human evolution.

The riddle in the desert, twice as tall as an average adult, drew scores of the curious to see it, even though its exact location was not made public.