The weather was cloudy on the evening of Friday 9 December but a fireball was so bright that it could clearly be seen from various parts of Andalucía. Its presence was picked up by detectors which form part of the SMART project (Spectroscopy of Meteoroids in the Atmosphere by means of Robotic Technologies), which aims to analyse interplanetary material which impacts on the Earth.
José María Madiedo of the Andalusian Institute of Astrophysics has confirmed that the fireball occurred at 9.32pm and was as bright as a full moon.
He said the rock had come from the 2004 TG10 asteroid and it entered the Earth’s atmosphere at a speed of about 107,000 kilometres an hour.
“These rocks which pass through the orbit of our planet are known as meteoroids,” he explained. When the rock came into contact with the air at such a high speed it heated up to a temperature of several thousand degrees centigrade and became incandescent. That is what made it look like a ball of fire which began at an altitude of 99 kilometres above the Atlantic Ocean.
The fireball ended with a violent explosion. “It exploded at the end of its trajectory and that made it look even brighter. That explosion was due to the rock suddenly breaking up. By then it had travelled about 64 kilometres through the Earth’s atmosphere,” Madiedo said.
The fireball was recorded by the SMART project detectors in Seville, Huelva and La Sagra (Granada). This project has been developed by the South West Europe Meteor and Meteorite Network, known as the SWEMN network. It is coordinated by the Andalusian Astrophysics Institute and it continually monitors the sky to record and study the impact of rocks from different objects in the solar system on the Earth’s atmosphere.