Space The Final Frontier By: Mrs. Cosnowski Inner Planets There are 4 inner planets MercuryVenusEarthMars All 4 of these planets are called terrestrial planets because the surface of the planet is similar to Earth. To learn the planets in order say the sentence: My Very Energetic Mother Just Served Us Nachos. The Sun The Sun is the center of our Solar System. Solar means sun which is why we call it a Solar System. The Sun makes energy by converting hydrogen (H 2 ) gas into helium (He) gas. The Sun is about 4.5 billion years old, and it will live for about 4.5 billion more years. The planets in order of size from largest to smallest Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury 1,000,000 Earths will fit into the Sun!!! Mercury It is the closest planet to the sun.It is the closest planet to the sun. Now that Pluto is a Dwarf Planet, Mercury is the smallest planet and is about 1/3 the size of Earth. It takes Mercury 88 days to orbit the sun. Mercury does not have an atmosphere. It has been discovered that Mercury has ice at its north pole that does not melt because of being shaded by craters. Venus Venus has an atmosphere with thick clouds made from a poisonous gas called sulfuric acid. This atmosphere traps the heat from the sun and makes Venus the hottest planet. Venus is sometimes called our sister planet because its similar to Earth in size. Venus rotates in a clockwise direction, the opposite of almost everything else in the Solar System. Earth Earth is the 3 rd planet from the sun. Earth has an atmosphere made primarily of oxygen (O 2 ), nitrogen (N 2 ), and argon (Ar). It takes 365 days to revolve around the sun. This is known as one year. The Earth is tilted on its axis by 23 degrees. It takes the Earth 24 hours to rotate one time. This is known as one day. 70% of Earth is covered in water. Moon The moon is about as old as the Sun making it about 4.5 billion years old.The moon is about as old as the Sun making it about 4.5 billion years old. It takes about 27 days to revolve one time around Earth, and to rotate on its axis one time. That means its day is the same length as its year. The moon is considered a natural satellite of Earth. Earth and all the planets are satellites of the Sun. The moon is about 1/6 the size of Earth and has the surface area of roughly Africa. There is no atmosphere surrounding the moon. The surface of the moon is mainly made up of a rocky composition. Humans first landed on the moon on July 20, The last time we were there was in December In November 2009 scientists found that there is water on the moon. A spacecraft named Clementine landed and recorded data. A lunar eclipse happens when the moon passes through Earths Shadow. It causes the moon to turn dark reddish in color. Mars Mars has a thin atmosphere made mainly of carbon dioxide (CO 2) and methane (CH 4 )gas.Mars has a thin atmosphere made mainly of carbon dioxide (CO 2) and methane (CH 4 )gas. The Polar icecaps on Mars have enough ice to cover the surface of the planet about 20 feet deep. Now the question becomes is there liquid water? It takes Mars 24 hours and 37 minutes to rotate one time. Mars has at least 3 moons. Mars is about the size of Earth making it difficult for Mars to hold on to an atmosphere. It takes 686 days to make one revolution. Mars has the Solar Systems largest volcano, Olympus Mons. Asteroid Belt After Mars there is a large gap before the next planet, Jupiter. In this gap is something called The Asteroid Belt. The Asteroid Belt is made up of two bands, the inner band and outer band. Most of the asteroids in the inner band are made of metal. Most of the asteroids in the outer band are rocky asteroids and are rich in carbon. One theory is that these asteroids never came together to form a planet because of Jupiters strong gravitational pull. 26 large asteroids have been found, but there are millions of smaller ones. Ceres is one of 5 dwarf planets in the Solar System and is located in the Asteroid Belt. The other 4 are Eris, Pluto, Makemake and Haumea. The End