What are asteroids?First of all I would like to say that the so-called rocky solid bodies that move through the solar orbits elliptically shaped like planets.However, space asteroids have a much smaller size than, in fact, the planets themselves.Their diameter is about probation within the following limits: a few tens of meters up to thousands of kilometers.
Wondering what asteroids person involuntarily and thinks about where all this came the term, what it means.He translates as "star-like", and introduced it in the XVIII century astronomer named William Herschel.
comets and asteroids can be seen as a specific point sources of light, more or less bright.Although in the visible range information celestial bodies radiate nothing - just reflect the sunlight which is incident on them.It should be noted that comets differ from asteroids.First - this is their different appearance.Comet easily recognizable by the glowing nucleus and tail, which comes from it.
Most of the asteroids, which are known to astronomers today are moving between the orbits of Mars and Jupiter at a distance of about 2.2-3.2 and.e. (ie, astronomical units) from the sun.To date, scientists have discovered about 20 thousand asteroids.Registered of them only fifty percent.What are asteroids with registration?This celestial body, which assigned a number, and sometimes even their own names.Their orbits are calculated with very high accuracy.It should be noted that these celestial bodies are usually the names that they have appropriated their discoverers.The name of the asteroid to take, as a rule, from Greek mythology.
Overall, from the above definition, it is clear that such asteroids.However, what is typical for them yet?
resulting from the implementation of these celestial bodies through a telescope observations was discovered an interesting fact.The brightness of the large number of asteroids can be changed, and in a very short time - this takes a few days or even a few hours.Scientists have long hypothesized that these changes in the glare of asteroids associated with their rotation.It should be noted that they are due to - the very first place - to their irregular shape.And the first pictures, which were sealed, these celestial bodies (the pictures are made using satellites) have confirmed this theory, but also showed the following: the surface of the asteroid is completely pitted with craters and deep craters of different sizes.
biggest asteroid discovered in our solar system, once considered a celestial body Ceres, whose size is approximately 975 x 909 km.But in 2006 she received a different status.And became known as a dwarf planet.And the other two large asteroid (under the names Pallas and Vesta) have a diameter of 500 kilometers!We should also note another interesting fact.The fact that the message - this is the only asteroid which actually visible to the naked eye.
