Unlike planets, comets move on highly elongated orbits, and therefore are visible only at short periods close to the Sun.
The main part of any comet is its nucleus .
According to the hypothesis of the famous American researcher of comets Fred Lawrence Whipple, cometary nucleus is an ice consisting of a mixture of frozen water and frozen gases interspersed with refractory rocky and metallic particles . Figuratively speaking, it looks like a “dirty iceberg”.
Let us imagine that we see the newly opened the comet, which is somewhere in the vicinity of Jupiter’s orbit. Seeing through the telescope hazy pale speck, like a spherical nebula (such unattractive are presented to the observer of a distant comet), we may be disappointed at first. With the approach of the comet to the Sun the solar flux increases. Comet “ice” begin to evaporate rapidly. Around the nucleus formed a vast glowing gas shell – coma. Together with the core of it is the head of the comet. Continue reading
Flight to Mars is planned by several countries, who are ready to launch to the red planet manned spacecraft within the next 30 years. However, despite such promising prospects, scholars continue to argue about the feasibility of such a flight.
You should start with the fact that one-way flight will take on a variety of calculations, from 7 to 9 months. Such a long flight is very dangerous as the technical side (increasing the probability of hardware failures) and physiological and also the psychological side. Will the astronauts be so many months in a confined space with very limited contacts? How will it affect the human body for long periods in a weightless condition? How great is the danger of radiation in interplanetary space? All these questions become very relevant in the context of emerging in a not too distant future flight to the red planet.
However, should carefully consider possible consequences and unforeseen circumstances that may confront astronauts involved in such a long expedition. First of all, you should bear in mind that absolutely not possible to interrupt the mission due to any circumstances, or to deliver to Mars new reserves in case of shortage. In this case the crew can only rely on their own strength. Continue reading
Space exploration mankind is just beginning. It’s only been 47 years since the launch of the first artificial satellite. At the dawn of the space seemed to fly on the next planet there are very few. The great powers of the world tacitly competed for the right to be the pioneers of space. As you know, the palm in this area belonged to the Soviet Union first launched into space man.
After the launch of Yuri Gagarin the world community recognized the absolute leadership of the USSR. But the main competitor – the United States of America – was not shared by the tumultuous enthusiasm about another giant leap of progress. And if the Soviet Union existed, the phrase “Catch up and overtake America!”, before members of the NASA task was to restore the eroded national prestige ahead of the Soviet Union in the space race. Three weeks after the flight of the first American astronaut in space, John F. Kennedy vowed America, after ten years since the Americans landed on the moon.
Indeed, on July 21, 1969 American astronaut first stepped on the moon. For Americans, this event was no less significant than the discovery of America or the Declaration of independence. Around the globe spread the pictures depicting the first inhabitants of the moon under the stars and stripes, and later shots of the film depicting a historic moment. With them and began don’t setaside this time the dispute about the lunar program. Continue reading