Possibly, comets brought water to Earth
To see exactly what is in the comet, it is necessary to analyse its substance with the help of different high sensitive devices, bringing samples to Earth. But aboard a small spacecraft such devices are difficult to place, because the size of the station Stardust 1,7×0,7×0,7 meters – about the same size as the Desk. How to take a sample of matter, flying from the comet’s nucleus at high speed? Space standards Stardust was moving slowly relative to the comet, about one and a half times slower than fly around the Earth artificial satellites. However, even this speed was several times greater than that of the bullet, the station flew over one second 6 km from the Contact of dust particles with the container of solid material at this speed (more than 20 thousand km/h) would have led to their strongest heating and evaporating. The only way to mildly catch and stop these dust particles, turned out to be a trap made of unique material – aerogel, which was established in 1931, but the big distribution has not received. Continue reading
Space flights cause a failure in the immune system of a person
The results of two studies of NASA, recently published in the journal journal of Interferon & Cytokine Research suggest that spaceflight may cause temporary changes in the immune system of crew members who are long time on Board the International Space Station.
Data obtained at an early stage of one of the experiments showed that the distribution of immune cells in the blood of crew members during the flight remained relatively unchanged. However, they found that some cell functions were significantly reduced, while the activity of another cell type, on the contrary, increased. That is, in a sense, the immune system of crew members, it failed.
If the cell activity is suppressed, the immune system cannot adequately react to threats, which can lead to asymptomatic for the virus. If activity is increased, the immune system becomes too sensitive, which can lead to the development of allergic reactions and persistent rashes, as well as reported some of the crew members.
In another study, scientists analyzed blood plasma, measuring the concentration of cytokines – proteins that regulate the immune system. Continue reading
People were engaged in agriculture in the stone age, 30 – 35 thousand years ago. This is evidenced by the notches on animal bones and rocks, cave paintings. This is, perhaps, the earliest “scientific notes”, in which the authors noted the different phases of the moon and count days and nights.
Monitored by our astronomical instruments, the universe consists by weight of about 76 percent hydrogen and 23 helium. Only slightly more than one percent accounts for all other elements of the periodic table.
It is estimated that the galaxy contains more than a hundred and twenty billion stars and to represent its enormous size, we will give one comparison: if the path from the Sun to Earth light travels in 8 minutes, the diameter of the galaxy it will for a hundred thousand years.
To show the progress made over half a century in the study of the Universe, astronomer Paul Couderc came to a startling comparison. Suppose that all known astronomy to 1900 area of the Universe displayed on the plan area of one square meter. Continue reading