Comets: the oldest inhabitants of the Solar system
J. L. Lagrange (1813) was also based on firmly established facts – the presence of comets that definitely move in elliptical orbits, including short-period. He explained the origin of comets gigantic volcanic explosions – emissions (eruption) with giant planets. It is, in principle, could explain the nature of the orbits of short-period comets. Subsequently, the views of La Grange shared and developed a number of scientists, among which the most important contribution of the Soviet astronomer S. K. Bo, who worked in this direction with the 20-ies to 80-ies of our century. He has eliminated the biggest internal difficulty is the concept of Lagrange – the necessity of the ejection of cometary masses (nuclei) with the “surface” of the giant planets with their powerful gravity fields, the overcoming of which requires an initial speed of 60 km/s and more. Giant planets also have thick (the length of many thousands of miles) and very dense atmosphere, in the middle of the twentieth century has been very problematic the very existence of a solid surface planets – giants beneath these atmospheres. Continue reading
The comet’s coma or head of the comet . is a fuzzy mist surrounding the actual nucleus of the comet. Including the tail, the coma is all we actually see, watching the comet from the Earth.
The shape and structure of the comet’s coma
The shape of the coma can vary from comet to comet and for the same comet during its passage, depending on its distance from the Sun and the corresponding quantities of dust and gas. Pale or bright comets producing little dust and often have a round shape, and comets that produce a significant amount of cometary dust have fan-shaped or parabolic shape.
This is due to released different-sized dust grains: those that are bigger are moving to the left along the trajectory of a cometary orbit, and the smaller particles are repelled from the Sun using light pressure.
Coma has 2 main components: gas-shell and shell dust. In fact, scientists believe that comets produce almost the same amount of gas and dust. Continue reading
“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. Continue reading