In 1998 Dutch scientist Dr. Eltjo Haselhoff discovered a remarkable track leading from a grass circle (at Hoeven, NL) to a ditch. The track contained dehydrated grass. The interesting thing was that the plants were effected this way at a height of approximately 20 cm. above the ground. This indicated that the track could not have been caused by people or animals walking through the grass. It seemed more likely that this had been caused by a ball of light, flying through the grass... (For more information about Dr. Haselhoff's crop circle research and the balls of light, see "What is the scientific opinion about crop circles?").
Also in Hoeven (NL), in 1998, Robbert van den Broeke witnessed multiple lights flying through his garden. He had witnessed these lights many times before, including in the company of multiple witnesses, one of which was American researcher and founder of the BLT Research Team Nancy Talbott. Robbert had also witnessed the forming of crop circles on various occassions in the past.
The balls of light that now flew through his garden and around the house, appeared from the ground, the trees, and out of nowhere. They also disappeared into the ground, the trees, and into nothingness. They hit the house several times, leaving traces of soot on the windows and window frames. (See pictures below). Obviously the lights were extremely hot! When a ball of light hit the window of Robbert's bedroom (on the first floor), the light sort of exploded, leaving a lot of white powder whirling down to the small balcony...
When the powder was analysed by the BLT Research Team, it turned out to be pure magnesiumoxide. Magnesiumoxide in itself is not an extraordinary substance; it is a common combustion product that - among others - is used by sports climbers to prevent their hands from becoming sweaty. However, ordinary magnesiumoxide always contains traces of the original material that was combusted in order to obtain the white powder. This magnesiumoxide, that swirled down from the 'exploded' ball of light in Hoeven, was so pure in its composition, that no traces of the original combusted material could be found. Such pure magnesiumoxide does not occure in free nature...
For an extensive description of this unique case in the Netherlands, click here.