An expert has warned that making contact with aliens could "spell the end of mankind".
Physicist Mark Buchanan has urged the human race to take a step back from the issue of extraterrestrial life as various videos have emerged of US Navy aircraft encountering "unidentified aerial phenomena".
Writing in the Washington Post newspaper, Buchanan said: "Chances are, we should all be grateful that we don't yet have any evidence of contact with alien civilisations.
"Attempting to communicate with extraterrestrials, if they do exist, could be extremely dangerous for us."
The scientist drew comparison with Christopher Columbus' arrival in North America, where an older civilisation was vulnerable to a more technologically advanced group.
Buchanan believes that it is highly likely that the human race is primitive when compared to inhabitants of other galaxies due to the relatively young age of our planet.