© NASACometary fragment crossing the atmosphere (archive).
A comet has exploded over the province of Cuenca and fragments of it have been seen from one of Spain's largest observatories in Toledo.

Scientists at the La Hita complex say comet number 169P/NEAT, which flew over the central region of Castilla-La Mancha on Wednesday night and the early hours of Thursday morning burnt out in the sky 79 kilometres above ground over the town of Cañamares.

Shards of rock plummeted downwards at a speed of 80,000 kilometres per hour and broke up when they hit the earth's atmosphere in a violent impact that turned them into bright balls of fire.

This was first seen at 23.50hrs mainland Spain time above Portugal and, at 00.07hrs, the largest and fastest fragment impacted with the atmosphere above the province of Málaga on the south coast, creating a fireball as bright as the moon.

A third impact was registered at 02.23hrs over Cuenca, shattering 100 kilometres above ground directly up from the village of Sotos, veering north until it extinguished over Cañamares.

Then, a fourth and final impact at 100 kilometres up was seen at 02.25hrs vertically above the Gulf of Cádiz on Spain's south-west coast.

These were all recorded by detectors used by the University of Huelva - Spain's westernmost province on its southern shores - stationed at La Hita in the province of Toledo, central Spain, as well as in observatories in Calar Alto (Almería province), El Arenosillo (Huelva province), Sevilla, and La Pedriza (Jaén province).

A preliminary analysis was carried out by astronomy professor José María Madiedo from Huelva University, who said all the comet shards became extinguished at heights exceeding 70 kilometres per hour and none of the rocks hit the ground, turning into dust in the atmosphere, meaning when they did finally reach earth they would have been impossible to detect.

The fireballs are associated with a cosmic shower known as the Alfa-Capricornida, which will continue active for several nights.

It is known to produce spectacular fireballs such as those seen this week, and others are likely to be detected over the next few days.