UFOs and Extraterrestrials

The Earth’s atmosphere is large and complicated. It is therefore not surprising that occasionally phenomena are observed in it that are not immediately understood. However, just because something unusual is seen in the sky does not imply that it is an extraterrestrial spaceship.

“It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.” – Sherlock Holmes.

For some of my personal history with the subject see UFOs? OK. Alien Spacecraft? No so fast.

Some references: