Interested in everything connected with high technologies.
Inside the comet 67P/Churyumov — Gerasimenko there are no large voids. The mission of “Rosetta” the European space Agency made measurements that clearly demonstrated and solved the old mystery. Comets are icy debris left over from the formation of the planets 4.6 billion years ago. Spacecraft have visited a total of eight comets, and through these missions we pulled a picture of the basic properties of these space-time capsules. On some questions the answers were found, others appeared.
Comets, as we know, consist of a mixture of ice and dust, and if there were compact, gravity superior to water. However, previous measurements have shown that some of them have very low density, much lower than water ice. Low density means that the comet must be extremely porous.
But what is this porosity: due to large voids in the subsurface of the comet, or due to a more homogeneous structure with low density? Continue reading
Comets are small Solar system objects that move in orbit around the Sun and can be observed as a bright point with a long tail. They are interesting for several reasons.
Since ancient times people have observed comets in the sky. Only once in 10 years, we can see the comet from Earth with the naked eye. Its impressive tail flashes across the sky for several days or weeks.
In ancient times comets were considered a curse or a sign of previous trouble. So in 1910, when the Ground caught the tail of Halley’s comet, some entrepreneurs took advantage of the situation and sold people masks, pills from the comet, as well as umbrellas to protect from comets.
The name of the comet received from the Greek word for “long-haired” because people in Ancient Greece thought that comets look like stars with flowing hair.
Comets tail appears only when they are close to the Sun. When they are far away from the Sun, comets are extremely dark, cold, icy objects. Ice body is called the nucleus. Continue reading
Radiation risk for astronauts (radiobiological rationale)
The book covers a fairly wide range of materials concerning the sources of cosmic rays affecting astronauts in the implementation of interplanetary and orbital space flight, the quantities of the doses, the reactions of individual systems and the whole organism of animals and humans, and changes its stability when the complex character of radiation exposure in space.
The results of a 14-year experiment on a large lot dogs with simulation values of the doses and nature of dose distribution in time, which will affect astronauts during the flight to Mars. The considered models of formation of radiation damage in the hematopoietic system and the level of the organism during long exposures with varying dose rate, and the model of radiation mortality rate of mammals, describing accelerated aging and the changing age-specific mortality rates in a dose-and dose rate radiation exposure.
The book presents the algorithms and results of calculations of the radiation risk in the process of interplanetary and orbital missions throughout the life of astronauts, as well as data on possible sacramentoa life expectancy. The new approaches to the regulation of radiation exposure and justifies the new lower acceptable dose to astronauts during flights and during the whole professional activity. Continue reading