The region of formation of comet Tempel 1 and the model of solar system formation
“Our observation was aimed at studying the chemical composition of the comet Tempel 1,” says Michael Mumma (Michael Turner) from space flight Center NASA Goddard (NASA Goddard Space Flight Center). The Mumma and his colleagues used a powerful telescope, the Keck Observatory in Hawaii for a detailed analysis of the light emitted by the gas of the comet at the moment of impact. Since each type of atoms and molecules has its own characteristic frequency of radiation, on the basis of this, scientists were able to determine the chemical composition of the comet’s nucleus.
Comets are blocks, which consist of ice and dust that move in elongated orbits. It is believed that the nucleus of the comet is gas and dust formations, remaining after the formation of the main bodies of the solar system.
When approaching the Sun, its radiation heats the comet’s nucleus, releasing dust and gas. The latter form a coma (cloud around the nucleus) and one or more tails. Repeated heating leads to the fact that disappear from the surface of the substance having a low boiling point. In fact, the nucleus of a comet is formed “crust” that is different chemically from its internal regions. This makes it difficult to determine the true composition of the comet just by studying the gas in its tail.
The mission Deep Impact has finally allowed scientists to look inside the nucleus of comet Tempel 1. So watching it before, during and after the collision, astronomically to separate the gases from the radiation surface of the radiation emitted by the impact of the materials. In this case it turned out that inside the kernel really has a different chemical composition. “The amount of ethane (C 2 H 6 ) in the cloud surrounding the comet, was significantly higher after impact than before it,” says Mumma.
There are two possible explanations of what happened. First, the surface layer is different from the internal structures due to solar heating (as written above). Second, the inner core is a collection of regions with different composition. It could be that the probe Deep Impact destroyed one of these areas, while the gas coming out of the core could be formed in a different area with a different composition. The ideal solution here would be a lot of strikes on the nucleus of the comet, in order to decide which of the options is correct.
In the case of the allegiance to the first theory, based on the chemical composition of the comet’s nucleus, is possible to conclude that it could be formed in the region of the solar system, where there are the orbits of Uranus and Neptune. The rationale is that depending on the position of the comet in her moribayassa different chemical compounds. Therefore, the comet, which will be located farther from the Sun, will have in its composition more gases with low boiling point (e.g., ethane). Thus, measuring the relative content of various substances in the comet, astronomers can estimate where it was formed.
Education Tempel 1 in this area also confirms the theory that Uranus and Neptune formed closer to the Sun than they are now. This model, proposed Morbidelli Alessandro (Alessandro Morbidelli), says that gravitational interactions between these planets and numerous minor planets, remaining after the formation of the solar system, has led to the instability of their orbital motion. In the end, Uranus and Neptune switched to a more distant orbit. While their gravitational influence has destroyed vast cometary disk that was in that area. The majority of comets were scattered far beyond the solar system, forming the so-called “Oort cloud” (Oort cloud) located at a distance of 10 thousand astronomical units. Other comets are trapped in the Kuiper belt (Kuiper belt), a region extending from Neptune’s orbit up to distances of the order of hundreds of astronomical units. If you find that the comet from the Kuiper belt and the ORT cloud have similar chemical composition, it will prove that this model of the formation of the solar system.