UFO PHOTOS

One things for sure, there have been a lot of unexplained mysteries over the centuries and with modern technology giving people greater access to photography and previously unexplored parts of the galaxy, there are bound to be plenty more cropping up.

We've tracked down some of the most famous alien and monster photographs ever taken to show just how weird and wonderful the world can be.

The Tunguska event has since led to much discussion about asteroid impact avoidance and has helped to spawn a multitude of science fiction films.

In June 1908, a massive explosion happened near the Stony Tunguska River in Russia. The explosion flattened 770 square miles of forest, toppling around 80 million trees and yet somehow resulted in no loss of human life.

It has been theorised that the Tunguska event, as it has been designated, was caused by an air bursting meteoroid but no one really knows for sure. There was no impact crater, so the conjecture is simply that it broke up in the atmosphere somewhere between three and six miles above the Earth's surface. The explosion is calculated to have been 1,000 times greater than that of the atomic bomb dropped on Hiroshima, Japan.

In 1959, in the Ural Mountains of Russia, an experienced group of trekkers died under mysterious circumstances which were never adequately explained.

In 1959, in the depths of the Ural Mountains of Russia, an experienced group of trekkers died under mysterious circumstances which were never adequately explained. Investigators discovered that the victims had cut a hole through their tent and run away from something while wearing minimal clothing despite the temperatures being around -30 degrees Centigrade.

A number of the victims died from hypothermia but some had inexplicable fatal injuries including a fractured skull, major chest fractures and one victim had brain damage despite no visible injury to their skull. Another of the victims was found with major injuries as well as missing tongue, eyes and lips. Several theories have been offered as to what caused the hikers to run and what eventually killed them, but none have been conclusive and their deaths remain a mystery.

In 1952 air traffic controllers from several airports and air force bases near Washington D.C. reported seeing unidentified blips on their radar screens.

In 1952 multiple air traffic controllers from several airports and air force bases near Washington D.C. reported seeing unidentified blips on their radar screens. When questioning local pilots, the controllers were told that a number of "bright lights" had been seen in the sky nearby.The next weekend, it happened again, this time with a dozen blips appearing on the radar screens. Fighter jets were scrambled to intercept but the jets were unable to match the speed of the unidentified flying objects. These sightings were added to list being investigated by the Government under Project Blue Book but nothing further was revealed.

In 2017, the Mars Curiosity Rover captured an image which appears to show an unidentified object on the surface of Mars.

There are a few images of Mars which have raised questions about whether there was once life on Mars or indeed whether there still is.

In 2017, the Mars Curiosity Rover captured an image which appears to show an unidentified object on the surface of Mars. Doubters have suggested it's merely debris from the Mars Rover itself, but the conspiracy theorists take this image as proof of the existence of extra-terrestrial life.

Over the valleys of Hessdalen in central Norway, a series of unexplained lights regularly appear through the day and night. Are they UFOs?

Over the valleys of Hessdalen in central Norway, a series of unexplained lights regularly appear through the day and night. Sometimes the lights appear for over an hour, sometimes they're there for just a few seconds. They're a regular occurrence and have had many UFO theorists claiming the lights to be of extra-terrestrial origin.

Scientists, however, have attributed the lights to a chemical and electrical reaction caused by the different metals and minerals in the local hillside reacting with the environment. Though it's not quite as exciting, it's certainly pretty.