The rotation of the celestial body characterized by its motion around its axis of rotation, while the treatment itself expresses the movement of celestial bodies in orbit around another celestial body. Thus, the Earth does not revolve around the sun, and applies for 365 diurnal rotation of the Earth. Blockquote> The existence of such an overweight "stabilizer" in the orbit of our giant-iron so much more unites it with gas and ice giants. The moon has a transverse diameter of 3476 km and is the fifth of the mass of the satellite in the solar system (after the largest satellites of Jupiter and Saturn). His matter is easy enough for a 5 planetoids mass of Pluto, and the remainder will be enough for two of the asteroid belt between the orbits of Mars and Jupiter!
The relative size of the Earth, Moon and Pluto i>
Earth-Moon system has the lowest ratio of the mass of the planet and its satellite in the solar system (previously owned by the Pluto-Charon system) superior to the earth in this regard the Moon "only" 81 times. For example, Saturn exceeds by weight Titanium is almost 3000 times!
Universe sized speck ...
Most of the Earth's mass, combined with a powerful magnetic field and the largest natural satellite made the main contribution to the diversity of our planet's climate. Many of us remember how in science fiction sagas of heroes travel to different worlds in which dominated a particular type of climate. This rocky planet Vulcan of Star Trek, hot Tatooine, frozen hut and forest moon of Endor in Star giant warriors. Of course this is only a simplification of the authors, and the population of the planet can be a great climatic diversity, as on Earth. On our stony-iron giant is a place for the entire universe of all possible landscapes - and boundless oceans, forests and impenetrable jungle and, of course, for the vast dazzling icy surface of the pole.
In this final (but not the last), the amazing and unique features of our planet, I would like to conclude this brief overview. However, it would be better to give the floor for a long time who left us, but left a solid intellectual heritage of Carl Sagan:
«Take a look again at this point. It's here. This is our house. This is us. All the people you love, everyone you know, all of whom you've ever heard, everything ever existed people have lived their lives on it. Many of our enjoyment and suffering, thousands of self-confident religions, ideologies, and economic doctrines, every hunter and collector, every hero and coward, every creator and destroyer of civilization, every king and peasant, every enamored couple, every mother and father, each capable child inventor and explorer, every teacher of ethics, each lying politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there - on a mote, suspended in a sunbeam.
Voyager 1, 1990, the distance - 6 billion km i>
Land - a very small stage in the vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph, they could become the momentary masters of the sand grains. Think of the endless cruelties committed by the inhabitants of one corner of this point of barely distinguishable inhabitants of the other corner. About how often differences between them, how eager they are to kill one another, how hot their hatred.
Our posturing, our imagined importance, the illusion of our privileged status in the universe - they all succumb to this point of pale light. Our planet - a lonely speck in the darkness of the surrounding space. In this enormous emptiness no hint that someone will come to our aid in order to save us from our own ignorance.
Land - is the only known the world capable of sustaining life. We have nowhere else to go - at least in the near future. To visit - yes. Colonize - yet. Whether you like it or not - the earth is now our home.
They say, astronomy instills humility and strengthens character. Perhaps there is no better demonstration of silly human conceit than this detached picture of our tiny world. I think it underscores our responsibility, our duty to be kinder to each other, to keep and cherish the pale blue dot - our only home. »
- Pale blue dot blockquote>
My publications close to the subject:
Extreme sister Earth. Past and Future "Morning Star»
Earthrise on the moon ... a common thing
What killed the "terrible lizards"? On the generators of mass extinctions