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
Solar system is a system of planets orbiting around a star, the Sun. Among those planets is our Earth. The solar System consists of the sun and of celestial bodies held by solar gravity. The mass of the sun is about 330 000 times the mass of the earth and makes up 99.8% mass entire solar system. The diameter of the sun is 1 400 000 km, i.e. about 109 Earth diameters. In the solar system except the sun is made up of eight planets, over 150 moons, and small bodies such as asteroids, comets and meteors.
In order of proximity to the Sun, the eight planets are mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
To measure distances in the solar system is used “astronomical unit” (AU). One AU corresponds to the distance from the earth to the Sun. Thus, the distance of one AU is nearly 150 million kilometers. For example, Jupiter rotates on its orbit 5.2 AU, i.e. the distance from the Sun is 5.2 times larger than the Earth. 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