2. Tinley Park

Patterns in UFO and UAP sightings across the world. A strange formation is seen in the sky over the sleepy suburbs of Tinley Park, Illinois. The lights return for a second time almost to the date the following year.

3. Alaska

In 2018, Alaska suffered a powerful earthquake that led to threats of a tsunami. Though the tsunami never occurred, one notable result of the quake was the increase in UFOs observed in the skies. But how does seismic activity link to sightings?

4. Sedona

A sacred place for centuries, the Arizona city of Sedona is known for its unusual occurrences. With all the activity that's been recorded here, it seems the red desert could double as an intergalactic airport. This programme considers what might be drawing UFOs to this spot.

5. The Pine Barrens

Built on swamp and sandy loam, all that grows in the Pine Barrens are the weeds of civilisation. However, there seems to be something about this barren land with its pygmy pines, high winds and frequent foresters that attracts alien attention.

6. Falkirk Triangle

With more than 300 UFO sightings each year, the townspeople living within the Falkirk Triangle cannot help but feel uneasy about the strange occurrences. From reports of abduction and missing persons to unexplained interference on airport radar, the cases are plentiful.

7. New Mexico

There is high strangeness on the Archuleta Mesa in New Mexico - and it's little wonder, what with the whisperings of the presence of an underground alien base. A near neighbour to Roswell, could Area 51 have been an elaborate decoy to divert attention from this facility?

8. California

Recent records show California has the most UFO sightings of any US state. A team of multi-disciplined experts - believers and critics - investigates what these Alien Corridors are and what they mean. From Joshua Tree, where people have reported more sightings per capita, to Mount Shasta, whose residents experience the longest visitations, lasting an average of 51 minutes.

9. Special Report: Why are They here?