As scientists it is our duty to keep an open mind about things and consider every possibility. It is nice to also chew the fat and theorise!

The antagonistic alien race of Silurians in BBC science fiction show Doctor Who are in fact a race of ancient reptiles that left the earth millions of years ago in search of a new home only to return and discover mammals had overtaken the planet. What if UAP are in fact advance probes of Earth's original owners wanting to move back in?