Close to midnight this Saturday, Portugal was surprised by a large meteor, lighting up the night with a blue-green flash.

Did it fall or not? If it did, it's a meteorite; if it didn't, it's a meteor.

Speaking to Lusa, geophysicist Rui Gonçalves explains that it is still too early to say whether the meteor actually fell and where.

The professor from the Polytechnic Institute of Tomar stressed that it was necessary to "gather more data" to be able to calculate the trajectory.

According to the researcher, the phenomenon was observed "from the French coast to the south of the Algarve".

Although he stressed that it is now necessary to cross-check the data, and that this work is not immediate, he added that Spanish members of the network, a country where there is more equipment and a greater possibility of recording with clear skies, estimate that "almost nothing fell from the meteor, or it ended up in the Atlantic", according to preliminary data from the Andalusian Astrophysics Institute.

In Portugal, the passage of the "gigantic bolide", with its "long duration and long trail", was observed at 23:46 on Saturday. In the Tomar town hall, "the record was very good", in São Brás de Alportel it only caught "the beginning of the event" and in Braga and Sesimbra the sky was cloudy and only the flash was seen, with no image.

According to the Astrophysics Institute of Andalusia in Spain, with whom the geophysicist has already spoken, the meteor entered the atmosphere at a speed of 161,000 kilometers per hour.

The trajectory has to be calculated
"Only after calculating the trajectory can we have any idea if there was any material left behind and where it fell, but that's not automatic," said the geophysicist.

The initial altitude of the luminous part of the event was 122 kilometers and it stopped being seen at an altitude of 54 kilometers, but Rui Gonçalves explained that this does not mean that it disintegrated at that point.

"They can shine up to an altitude of 30/40 kilometers. Normally, you can't see them from there, it's called dark flight. That has to be calculated, and that part is more difficult to calculate, because we have to make a series of assumptions to calculate where the pieces might have fallen," added the researcher, speaking to the Lusa news agency.

Nuno Peixinho, a researcher at the Institute of Astrophysics and Space Sciences at the University of Coimbra, also pointed out that there is a network of cameras in Portugal and Spain, activated automatically, to record these phenomena and that, by cross-referencing this data, it is possible to see whether or not it has fallen and calculate, with some margin of error, the location.

"They are pieces of rock that come at high altitude and speed, between 10 and 70 kilometers per second," explained Nuno Peixinho, speaking to the Lusa news agency.

Chemical process in question
Nuno Peixinho explained that, like shooting stars - although these are much smaller - they are consumed in the atmosphere and it is this chemical process that results in the trail of light that we see, which in the case of the blue "indicates that the type of material that is burning, vaporizing, is magnesium".

"As they move at several kilometers per second, against the air, the pressure they put on the atmosphere is so great that temperatures easily reach 25,000 degrees, and at that temperature they vaporize everything," he said.

The researcher stressed that, "as we're taught at school, if it fell to the ground it's a meteorite, if it didn't it's a meteor".