A short video clip shows a series of large footprints indicating a stride much greater than that of any human.
Exactly how massive elliptical galaxies form had remained a major and enduring conundrum for many years.
The exact origins of the Beluga whale, which turned up dead earlier this year, had long remained a mystery.
Medical experts have been left scratching their heads over the mystery of how the late nun's body has remained intact.
The clip shows a strange object that remained stationary over the Brazilian city of Curitiba.
For years, archaeologists have remained divided over the discovery of alleged giant skeletons and artifacts.
Where great white sharks give birth has long remained one of the most enduring mysteries in shark science.
The symbolic clock remains perilously close to armageddon with 'billions of lives' currently under threat.
For centuries, the whereabouts of the celebrated astronomer's final resting place had remained a mystery.
The nature of consciousness and whether or not it pervades the entire universe has long remained a topic of debate.
The phenomenon, whatever it was, showed up at around 10:30 p.m. on June 22nd and remained there for 20 minutes.
The blunder, which had remained undiscovered until very recently, may never be rectified due to the painting's fragile state.
This footage of an alleged Bigfoot-type creature emerged 8 years ago and has remained a topic of debate ever since.
The tube, which was collected by the crew of the Apollo 17 mission, has remained untouched for 50 years.
The symbolic clock has remained at the same ominous position now for three years in a row.
Eerie photographs of a clown captured on a trail camera have remained a topic of debate for years.
The cigar-shaped interstellar visitor has remained a topic of heated debate among scientists for several years.
Archaeologists have discovered 13 ancient Egyptian coffins that have remained untouched since antiquity.
A unique form of singing that produces two tones simultaneously has remained an enigma for many years.
Access to the wreck of the world-famous vessel, which sank in 1912, has long remained a point of contention.