Photo: NASA / Reuters
405 every thousand years the Earth’s orbit is slightly elongated due to the gravitational influence of Jupiter and Venus, which changes the planet’s climate and influences the development of life on it, including leads to mass extinctions. To such conclusion scientists led by Dennis Kent (Dennis Kent) from Rutgers University. About it reported in a press release on EurekAlert!.
Cycle 405 thousand years was predicted based on the calculations of planetary motion, however, the results of theoretical modeling were significant only for the last 50 million years. With a relatively small increase in the eccentricity (degree of deviation from a circle) of Earth’s orbit is also closely related to the changes in the location of the magnetic poles of the planet.
The researchers obtained more detailed data on changes in the direction of Earth’s magnetic field, analyzing the sediments in the rift basin of Newark (new Jersey) and sediment in a geological formation Chinle Formation (Arizona). They removed the core, dated to the late Triassic period in the time interval from 253 to 202 million years ago. The samples had the minerals zircon with inclusions of magnetite crystal by which to judge the state of the magnetic field of the planet.
The results obtained were consistent with theoretical calculations that allows the use of the cycle for a more accurate Dating of events on Earth events, including the Triassic-Jurassic extinction, the disappearance of a large number of animal species, freeing ecological niches the dinosaurs.
Video, photo All from Russia.