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
About the discovery of the ninth planet of the Solar system two astronomers from the California Institute of technology in Pasadena became known on January 20. One of them — the native of Russia Konstantin Batygin — spoke about the search for Planet X, the difficulties with the title the new heavenly bodies and unsolved mysteries of the Solar system.
What is an open planet?
Konstantin Batygin . She falls into the category of dwarf planets. This celestial body is quite massive. Our model gives a mass of about ten earth, this planet is just a giant. Now it is defined as a celestial object whose gravitational field is dominant in that part of the Solar system.
In General, there is not even a question: it’s a planet or not. We know about it, because its gravity affects the orbit of the farthest objects in the Kuiper belt. The very mathematical modeling relies on the fact that this planet has enough mass for gravity to dominate in the Solar system. Continue reading
Manned flights on the orbital stations
In the first decade of the era of manned spaceflight duration increased from 108 min to 18 days. Made in this period, medical and biological research (in the Russian ships “Vostok”, “Voskhod”, “Union”; in the U.S. project “mercury”, “Gemini”, “Apollo”) have proved the possibility of relatively short-term (up to 2-3 weeks) stay safe man in the space flight environment and active activities outside of the ship.
The most significant changes in the major systems of the human body were observed after flights. They were shown to decrease the body’s resistance to physical and orthostatic stress; impaired coordination of movements and regulation of the vertical posture; a reduction of body weight, hydration of the body, decreasing the volume of blood plasma and erythrocyte mass; asthenia. These changes in General increased with increasing duration of space flights and after flights, lasting 14 to 18 days, were practically significant.
Post-flight revealed improvements of indicated that to further increase the duration of flights you need to apply a system of appropriate protective and preventive measures that will facilitate adaptation of the human body to terrestrial conditions after the completion of the flight. Continue reading