In these chapter we will learn how the force of gravity was discovered by Newton, hoe the sun affects the earth, the live in it, and we will compare the difference between the moon and our beloved planet
Sun: The Sun is the Solar System´s star, and by far its chief component.Its large mass (332,900 Eath masses) produces temperatures and densities in its core great enough to sustain nuclear fusion, which releases enormous amounts of energt, mostly radiated into space as electromagnetic radiaton.
Mercury: Mercury is the closet planet to the Sun and the smallest planet in the Solar System. Mercury has no natural satllites, and its only known geological features beside impact craters are lobed ridges or rupes, probably produced by a period of contraction early in its history.
Venus: Venus is close in size to Earth, and likeEath, has a thick silicate mantle around an iron core, a substantial atmosphere and evidence of internal geological activity. Venus has no natural satellites. It is the hottest planet, with surface temperatures.
Earth: Earth is the largest and denset of the inner planets, the only one known to have current geological activity, and is the only place in the universe where life is known to exist. Earth´s atmosphere is radically different from those of the other planets, having been altered by the prensence of life to contain 21%free oxygen. It has one natural satellite, the Moon, the only large satellite of a terrestrial planet in the Solar System.
Mars: Mars is the smaller than Earth and Venus. It possesses an atmosphere of mostly carbon dioxide with a surface. Its red colour comes from iron oxide (rust) in its soil. Mars has two tiny natural satellites (Deimos and Phobos) thought to be captured asteroids.
Jupiter: Jupiter is 2.5 times mass of all the other planets put together. It is composed largely of hydrogen and helium. Jupiter´s strong internal heat creates a number of semi-permanent features in its atmosphere, such as cloud bands an d the Great Red Spot. Jupiter has 63 known satellites. The four largest, Ganymede, Callisto, Io, and Europa, show similarities to the terrestrial planets, such as volcanism and internal heating. Ganymede, the largest satellite in the Solar System, is larger than Mercury.
Saturn: Saturn is distnguished by its extensive ring system, has several similarities to Jupiter, such as its atmospheric composition and magnetosphere. The rings of Saturn are made up of small ice amd rock particles. Saturn has 62 confirmed satellites;two of which, Titan and Enceladus, show signs of geological activity, though they are largely made of ice. Titan,the second largest moon in the Solar System, is larger than Mercury and the only satellite in the Solar System with a substantial atmosphere.
Uranus: Uranus is the lightest of the outer planets. Uranus has 27 known satellites, the largest ones being Titania, Oberon, Umbriel, Ariel and Miranda. It has a much colder core than the other gas giants, and radiates very little heat into space.
Neptune: Neptune though slightly smaller than Uranus, is more massive. It radiates more internal heat, but not such as Jupiter or Saturn. Neptune has 13 known satellites. The largest, Triton, is geologically active, with geysers of liquid nitrogen. Triton is the only large satellitewith a retrogade orbit. Neptune is accompanied in its orbit by a number of minor planets, termed Neptune Trojans, that are in 1:1 resonance with it.
*Conclusion: Force of gravity is very important to keep everything in place including earth it self, these force of gravity keeps the others planets in the solar system in their orbits but most of all prevents earth to fall into the deep space.
