Near-solar origin of meteorites
If an iron meteorite falls to Earth, there is a high probability that it came from the asteroid belt that stretches between the planets Mars and Jupiter. However, its progenitor probably did not form there, but rather in the area of the inner planets Mercury, Venus, Earth and Mars.
This is the conclusion reached by scientists from the USA and France led by William Bottke from the Southwest Research Institute in Boulder. Using a computer model, the astronomers simulated the fate of thousands of chunks amid a cluster of protoplanets ranging in size from Earth's moon to planet Mars. A similar scenario is suspected for the early days of the solar system, when the planets were just beginning to form.
The data suggests that iron meteorites may have formed from the same host material as the inner planets. During collisions and the destabilizing gravity of the larger bodies, they were simply swallowed up or thrown into an orbit farther from the Sun, where we can still observe them with good telescopes today.
The objects owe the separation of the components and thus the formation of their iron-containing core to some radioactive elements with short half-lives according to the model. The energy released during decay heated the material so much that the iron could melt and seep through to the center with its high density.
If the simulation gives an accurate picture of the development in the early solar system, iron meteorites would in principle be small relatives of the earth that have not connected to other planets.
