The French Space Agency (CNES) has become the first national body in the world to open its archives on sightings of unidentified flying objects (UFOs). Visitors can already access online a quarter of the 1,600 UFO cases, which were collected from across France over the last 30 years. The database includes documents and eye witness accounts of strange phenomena. Once digitised, accompanying videos and photographs will be added to the collection. Many of the strange apparitions reported in the database have since been explained. Some were found to be hoaxes (for example human-made wheat crop circles), while others turned out to parts of a meteorite or debris from a satellite falling back to Earth. However, the agency estimates that 28% of the sightings listed remain unexplained. For example, in 1967, two young children tending a herd of cows caught sight of four small black beings around 1.2 m in height, who rose into the air and entered into a spherical shape which zoomed away, leaving behind it a sulphur-like smell and burnt grass. The children's account was corroborated by another witness, who heard the whistling noise of the flying object and smelt the sulphur, but did not actually see the object. A second inquiry was made by CNES, but it has found no rational explanation to date for the encounter. Another sighting which has miffed experts came from an Air France flight crew in 1994, who observed a large reddish brown disc - whose shape was constantly changing - hovering at an altitude of 10,500 metres. The disc was picked up on radar, confirming the crew's sighting.