Creator asteroid

Last week, a group of scientists from Ohio University suggested that 250 million years ago, the Earth survived the impact of a giant asteroid, which left a truly indelible mark on our planet. Perhaps it was because of this cosmic collision that Australia subsequently separated from the ancient continent of Gondwana. Moreover, there is an assumption that this catastrophe caused a mass extinction of animals and plants, when most of the previously thriving species disappeared on Earth during a relatively short prehistoric period.

The crater left by the supermeteorite was discovered by satellite observations under the ice of what is now Antarctica. Now it is located in the Wilkes Land area, and its diameter is almost 500 km. According to the researchers' calculations, the size of the asteroid that left such an impressive mark could reach 30 miles (more than 48 km). It is possible that this is the largest meteorite ever to crash into our planet. Until now, the record was held by an asteroid that fell 65 million years ago in the area of ​​​​what is now the Yucatan Peninsula in Mexico. Scientists believe the meteorite measured up to six miles (9.6 km) in size, and the Chicxulub crater it left behind is 180 km in diameter. It is assumed that the consequences of this disaster led to rapid climate change on Earth, which caused the extinction of dinosaurs.

Ohio University geology professor Ralph von Frese, one of the leaders of the study of the new Antarctic crater, said that “the impact on Wilkes Land was much more powerful than the one that killed the dinosaurs; it is possible that it could cause a catastrophic impact.” This could have dramatically changed the environment and caused mass extinctions and changes in flora and fauna during the Permian and Triassic periods. In addition, the asteroid impact could have provoked the later split of Australia and Antarctica, which previously formed a single continent: a crack in the earth’s crust separating these continents runs right in the area of ​​the crater. However, this conclusion is considered controversial. Other geological evidence calls into question the direct influence of the giant meteorite on the continent's breakup.

But, as it turns out, not every asteroid is capable of splitting continents and causing a planet-wide catastrophe. Japanese scientists have finally analyzed the first data on the Itokawa asteroid obtained using the Hayabusa probe. This device was launched to this small planet back in 2003 and was, in particular, supposed to collect soil samples. However, problems arose with this. “Hayabusa” did not manage to “strike” the asteroid for a long time (for more details about the adventures of the probe in space, see the issue of Vremya Novostei dated November 22, 2005) . The device has not yet returned to Earth (this will happen only in 2010), but photographs and other data obtained from orbit allowed its creators from the Japanese Space Exploration Agency (JAXA) to claim that an asteroid like Itokawa is practically not on our planet. scary.

According to JAXA representative Akira Fujiwara, Itokawa turned out to be very loose in its structure: it consists of a mixture of gravel and rock, which are connected to each other only by the force of gravity, RIA Novosti reports. As Fujiwara notes, such “small” asteroids, if their flight path intersects with the Earth, pose much less danger, since they can collapse in the layers of the atmosphere before reaching the surface. In addition, due to their loose structure, they will not be very difficult to destroy with modern weapons.

Mikhail MANSKOY