Our Solar System
Our solar system was first observed by the Greeks. They saw that there were several points of light that "wandered" slowly with the stars, and the Greek named them planets. The Romans later gave them names: Mercury, Venus, Mars, Jupiter, and Saturn. Our solar system is 11, 830,000 km wide. Our solar system consists of many objects.
The Greek discovered that the solar system consisted of planets, but that was not it. Our solar system contains many planets, asteroids, a star(the sun), comets and meteors. It consists of the sun, the planets and their moon(s), and several kinds of smaller objects that revolve around the Sun.
The heliocentric theory was belief that the solar system revolved around the sun. Many were not willing to believe this theory, but it was eventually proven by Galileo Galilei in 1610. He proved that the geocentric theory-which was the theory that the solar system revolved around the earth- was incorrect.
There are two different types of planets in our solar system:
The terrestrial planets are small planets that are closest to the sun and before the asteroid belt. They have few or no moons at all, and have dense and rocky surfaces. The gas giants, however, are huge balls of gas with no surface. They have many moons and have rings around them.
The terrestrial planets are small planets that are closest to the sun and before the asteroid belt. They have few or no moons at all, and have dense and rocky surfaces. The gas giants, however, are huge balls of gas with no surface. They have many moons and have rings around them.
Gravity plays a very important role in the structure of solar system. The suns gravitational pull holds the solar system together and keeps it in an elliptical orbit. If not for the suns gravitational pull, the planets would all collide into one another. The planets also have a gravitational pull that holds their moons in an orbit.
There are many theories about how the moon was formed. The accepted theory now is that 4.45 billion years ago, a large object not he size of Mars hit the earth while it was still forming. The debris from the collision was mushed together and the moon was formed. There are other theory too, such as one where the moon was a wanderer and was pulled into Earths gravity. Gravity, though, can not do that, so this theory was disregarded.
Credit: curiosity.discovery.com
Credit: curiosity.discovery.com
As a child, we used to believe that the moon was made out of cheese. But in reality the moon is made out of craters and mountains. These give the moon an uneven surface, that looks a bit like cheese. Craters are formed when objects flying around in space, like asteroids or meteors, hit the surface of the moon.
The earths orbits in space by two ways, rotation and revolution. Rotation is defined by the spinning on its axis. It is the reason why we have day and night, because when we face the sun, it is day and when we face the other way it is night. Revolution describes the earths orbit around the moon. One complete revolution around the sun is called a year. The orbit of the earth is in an elliptical shape.
What are the two factors that keep the Earth and the Moon in an elliptical orbit? If it was only gravity, then the Earth and moon would crash into the sun. But Isaac Newton concluded that two factors-inertia and gravity-combine to keep Earth in orbit around the sun and the moon in orbit around the Earth. Inertia is the tendency of an object to resist a change in motion, and because the Earth is so big, it has a great amount of inertia that keeps its orbit around the sun.
Comets is the universes shooting stars. They are loose collections of ice, dust, and small rocky particles whose orbits are usually very long, narrow eclipses. They have a head and a tail. The head of the comet is a fuzzy outer layer called the coma, and it is the brightest part of the comet, also with a nucleus. The tail consists of two separated tails, the gas tail and the dust tail. Always pointing away from the sun, there is little mass in this part of the comet.
Asteroids are small rocky objects that are too small and too many to be called planets. Most asteroids revolve around the sun in fairly circular orbits between the orbits of Mars and Jupiter. This region is known as the asteroid belt.
Meteoroid are chunks of rock or dust in space that usually come from comets or asteroids. When they enter the earths atmosphere, they become meteors It creates heat and produces a streak of light in the sky because of the friction with the air. When meteors hit earth, they are called meteorites. The craters of the moon were formed by meteorites.