Some experts are starting to support the theory that the fall of a giant meteorite some 2 billion years ago may have created the Czech basin, surrounded by mountain ranges, reminding of a crater and easily detectable from high altitudes, writes the weekly Tyden out today.

Up to recently, the Czech basin's formation has been ascribed to plate tectonics.

"The plate tectonics, including the earth crust movements, became a geological religion of the past century. This has slightly overshadowed the fact that the Earth is also a part of space," said Petr Rajlich, a university teacher and geologist from the South Bohemian museum in Ceske Budejovice.

A crater of Bohemia's size "is unprecedented in terms of energy necessary for its creation. Moreover, its emergence has never been registered by people in their history. If it had been so, the possible witnesses would have been the last humans living on the Earth," Rajlich told the magazine.

American scientists reportedly admitted the "cosmic impact" origin of the Czech basin when they saw its satellite photo taken at the altitude of 36,000 km in the late 1980s.

The Americans, however, wrongly put the period of the meteorite's possible fall at 100 million years ago. In addition, they submitted no geological arguments, says Rajlich.

Perhaps no other inland country is as easily detectable on a plastic map as the Czech Republic. "The best explanation for a circular structure of such dimensions can really be the fall of a meteorite," says Vaclav Cilek, head of the Czech Geological Institute.

The caved-in earth crust below Bohemia also speaks in favour of the impact theory, Cilek adds.

"Indeed, the geological origin of Bohemia really shows several unclear aspects we are unable to properly explain using the old plate tectonics theory and which could support the impact theory," said Radek Mikulas from the Geological Institute.

"Nevertheless, the round shape of the Czech basin can also be explained in many other ways," he said.

Experts are split on the issue, but they agree that geological proofs would be crucial for the recognition of the Czech basin's "cosmic" origin.

"The whole event would have to be a huge blow in the centre of Europe that would transform [the composition of] the upper part of the Earth's mantle into considerable depths. As a result, brectias and other unusual rocks would have to occur in the area now," according to Vladimir Bouska, a late expert and Charles University teacher.

According to Rajlich, more and more proofs have been uncovered in support of the cosmic impact theory.

Some Czech minerals show a dense network of defects caused by extreme pressures and comparable with those registered after underground nuclear blasts, he says.

Some rocks in Bohemia are mixtures of elements that do not "match" each other, as if formed of meteorites and the Earth's crust.

Minor diamonds and titan oxides have been found 15 km to the north of the Czech-German border. They arose under extreme pressures as a possible product of the crater's shock waves, Rajlich says.

Some types of rocks in Bohemia are identical with the rocks uncovered in Vredefort, South Africa, and Sudbury, Canada, the world's two craters with supposed cosmic impact origin, Rajlich says.

In addition, there is no better explanation for the Czech basin's circular shape with the depression that is the deepest some 50 km southeast of Prague, he says.

The possible meteorite whose fall might have formed what are the Czech Lands now, was some 20 km long and it hit the Earth at a speed of 50 km per second. It caused an explosion identical with thousands of nuclear bombs.

Millions of cubic metres of rocks were shifted and even a large part of mass evaporated.

It created a hollow with a 300-km diameter and two kilometres deep. The crater's edge, on its part, moved 2 km upwards. It is now copied by the Czech border mountain ranges, Tyden writes.