Comets are Solar system bodies having the form of vague objects, usually with pale clot kernel in the center and tail. They are among the most beautiful celestial bodies. hazy Bright shell surrounding a core of hazy, long tail, extending sometimes to half the sky, fast motion among the stars – all this makes comet different from other heavenly bodies. The comet can be observed when a small ice body, called the nucleus of the comet is approaching the Sun at a distance that is less than 4-5.e. warmed by the sun, and it begins to stand out gases and dust that are visible as a result of their illumination by the Sun.
Gases and dust released from the nucleus, creating around him a hazy shell – atmosphere of the comet, components along with the core of the head of the comet. The atmosphere of a comet continuously dissipates in interplanetary space: under the action of radiation pressure and interaction with the solar wind gases and dust are carried away in the direction from the Sun forming the comet’s tail.
Most of the comets in the middle of the head there is a bright star-like “core”, representing the illumination of the Central, most dense zone of true gases around the comet’s nucleus. Continue reading
Comets fascinate the human mind since ancient people first noticed the white tail streaking through the night starry sky. We remember the date when the comet flies past the Earth once a century or even less often and remember all our lives. In the middle ages in Europe, the appearance of comets was often linked to various natural disasters and diseases. In religion, these heavenly bodies also play an important role. For example, in the New Testament, the comet heralded the birth of Christ.
Astronomers find comets also interesting and fascinating space objects, because they are witnesses of great historical events and even carry evidence of them.
The comet is a relatively small object in our solar system, usually having a diameter of several kilometers. Sometimes called “dirty snowballs” because of their component substances. Usually comets are composed of the following four elements:
Ice (water, ammonia, methane, carbon dioxide)
Some organic materials (e.g., resin)
Rocky ground (optional) Continue reading
I must say that the problem of space distances increasingly asserting itself. Chemical rockets on its effectiveness has exhausted itself for the future. Even the nearest planets of the Solar system on them to fly extremely long. Nuclear space engines while not in orbit, but on paper. Ion on a large scale. The spacecraft with solar sails will be valid only within the Solar system.
What engine to fly to the stars and how? After all, even with a nuclear engine will take flight for decades and centuries! Why? Because, according to theories, it is impossible to exceed the speed of light. And by estimations of astronomers, the nearest star to Earth with exoplanets (a planet similar to earth) is at a distance of 13 light years.
It is about exoplanet Kapteyn b, which is presumably suitable for life. For those who do not know: for light year, the astronomers believe the distance that a beam of light passes in our earth year at the speed of 300,000 kilometers per second. Other discovered exoplanets: Gliese 832c (16 light years), Gliese 667 Cc (22,7 light years), Kepler 186f (500 light years), Kepler 62f (1200 light years). But on a normal ship flight to the nearest star to us (alpha and Proxima Centauri – the distance in four and a half light years) will take time-75 thousand years. Of course, not light, but ordinary, earthly years. Continue reading