The Solar System By Francesca Tonelli and Alessio Calandra Introduction In this presentation we will : - explore the eight planets and their features. - compare and contrast the similarities and differences of the “inner” and “outer” planets. Let’s start with the Sun Diameter: 1.4 million kilometers Contains 99.8% of the mass of the solar system The volume of the Sun could hold 1 million Earths. Composition: 75% hydrogen, 25% helium Surface Temperature: 5500 oC Rotates on its own axis once every 25.4 days at the equator. Revolves around the center of the Milky Way Galaxy once every 225 million years. Core Temperature: 15 million degrees Celsius How about the planets? The solar system is divided into two basic groups. The inner and outer planets. The inner planets lie inside of the asteroid belt and consist of Mercury, Venus, Earth, and Mars. They are four of the five smallest planets in the solar system and are often called terrestrial planets because of their similarities with Earth. They have high densities because of heavy metal cores. Mercury Mercury is the eighth largest planet (or second smallest) in the Solar System. Mercury is a heavily cratered planet, composed of rock with a central iron core that is threequarters of the diameter of the planet. Following the Earth, Mercury is the second densest planet in the Solar System. Covered with thousands of craters, the surface of Mercury closely resembles the Earth's Moon. Mercury has few non-cratered areas on the surface, with the exception of the large flat area known as the Caloris Basin, and a few other small areas. More on Mercury The surface temperature of Mercury is characterized by major fluctuations. The daytime side of the planet reaches over 400 degrees C , but on the night side the temperature falls to -170 degrees C. Mercury has no atmosphere and no known satellites. Mercury was believed by the Greeks to be two different stars. Mercury's appearance in the morning was called Apollo, and its evening appearance was referred to as Hermes. Position: Closest to Sun Distance from Sun: 57,910,000 km Mercury Day: 58.65 Earth Days Mercury Year: 87.97 Earth Days Orbital Speed: 47.8 km/sec Eccentricity of Orbit: 0.206 Satellites: None Diameter: 4,878 km Mass: 3.30e23 kg Venus Venus is the sixth largest planet in the Solar System. Similar in size, density, and mass, Venus and Earth often referred to as sister planets. However the surface and atmosphere of the two planets are drastically different. The atmosphere of Venus is primarily composed of carbon dioxide and nitrogen, with traces of other gases and little to no water vapor. Venus would have a cold climate if it weren't for the high concentration of carbon dioxide in its atmosphere. In fact the surface temperature of Venus is over 480 degrees C. More about Venus Magellan Probe Computer Generated Surface Image The clouds in Venus' atmosphere are composed of sulfuric acid which causes the planet to reflect 65% of the sunlight that reaches it. The surface of Venus is very dry with flat plains, highland regions, and depressions. The interior of Venus is composed of a central iron core and a molten rocky mantle, similar to the composition of Earth. Venutian info Position: Second from Sun Distance from Sun: 108,200,000 km (.72 AU) Venus Day: 243 Earth Days Venus Year: 224.7 Earth Days Orbital Speed: 35 km/sec Eccentricity of Orbit: 0.007 Satellites: None Diameter: 12,100 km Mass: 4.869e24 kg Major Atmospheric Gas: Carbon Dioxide The Third Planet - Earth Diameter: 12.7 thousand kilometers Mass: 6.0 x 1024 kilograms or six sextillion metric tons Composition: water, silicon, carbon, heavy metal ironnickel core Atmosphere: nitrogen, water vapor, oxygen, carbon dioxide Surface Temperature: -13 – 37oC Called the “Blue Planet” because of the color of nitrogen in it’s atmosphere. More on the Earth The Earth rotates on an axis that is tilted 23 ½ degrees relative to the orbital or ecliptic plane. It’s period of rotation is one day or 23 hours and 56 minutes. The period of revolution around the Sun is a year or 365 and onequarter days. Earth info Earth is the fifth largest planet in the Solar System. The Earth is around 4.6 billion years old. Earth is the only presently known planet in the Solar System to support life. 71% of Earth's surface is covered in water. The Earth is the densest planet in the Solar System. The Earth has only one satellite, the Moon. The Moon is the second brightest object in the sky. Position Third from the Sun Distance from Sun: 149,600,000 km Earth Day: 24 hours Earth Year: 365 Earth Days Orbital Speed: 29.8 km/sec Eccentricity of Orbit: 0.017 Satellites: 1 Diameter: 12,756 km Mass: 5.976e24 kg Major Atmospheric Gas: Nitrogen Moon The Moon is the only natural satellite of the Earth, and the fifth largest satellite in the Solar System. It is the largest natural satellite of a planet in the Solar System compared to the size of the other natural satellites. Red Planet - Mars Mars is the seventh largest planet in the Solar System. Known as the Red Planet, Mars is characterized by its red, dusty landscape. In observation of Mars seasonal changes and river channels on the surface, many scientists hoped for a possibility of Martian life. They speculated that the composition of Mars' was similar enough to Earth to support life. However, the atmosphere on Mars is very different than Earth's, with only small amounts of life supporting oxygen and water. More on Mars Temperatures on Mars vary from a maximum of 0 degrees C to minimum -100 degrees C . The terrain on Mars is complex and varied, with deep canyons, mountains, volcanoes, and craters. Olympus Mons, the largest mountain in the Solar System, stands on Mars with an altitude of 24 km Valles Marineris is a system of canyons that stretch out over the surface of Mars for nearly 2,500 miles. Position: Fourth from Sun Distance from Sun: 227,940,000 km Mars Day: 24.6 Earth Hours Mars Year: 686.98 Earth Days Orbital Speed: 24.2 km/sec Eccentricity of Orbit: 0.093 Satellites: Two Diameter: 6,794 km Mass: 6.4219e23 kg Major Atmospheric Gas: Carbon Dioxide Mars’s story Mars was first visited by the Mariner 4, in 1965, which transmitted 22 pictures of the Martian surface back to Earth. The pictures revealed that there was no water or life on the cold surface, shattering hopes to find life on Mars. There has been no proof to date that there was ever life on Mars. Mars is the god of war in Roman mythology. Mars has two small satellites named Phobos and Deimos. Mars Rover currently on Mars Phobos and Deimos Mars has two relatively small natural moons, Phobos and Deimos, which orbit close to the planet. Asteroid capture is a long-favored theory but their origin remains uncertain. A possibility is the involvement of a third body or some kind of impact disruption. Phobos Deimos The Outer Planets The outer planets consist of four gas giants, Jupiter, Saturn, Uranus, and Neptune Finally Pluto that is recategorize in 2006 as a dwarf planet (is a celestial body in direct orbit of the Sun) ,Charon, Nix and Hidra. Asteroid Belt Asteroids are small rocky objects that move in elliptical orbits in the asteroid belt between the orbits of Mars and Jupiter. Their average distance from the Sun is about 2.9 astronomical units (A.U.) Jupiter Jupiter is the largest planet in our solar system. It has 62 moons. The largest four were discovered by Galilei Galileo. Io, Europa, Ganymede and Callisto Jupiter is the fourth brightest object to be seen in the sky. Occasionally Mars will appear to be brighter than Jupiter in the Earth's sky. Io, Europa, Ganymede and Callisto Jupiter info Jupiter spins faster on its axis than any other planet in our solar system. One day on Jupiter is 9.8 Earth hours Jupiter is a gas planet, composed largely of hydrogen and helium, with traces of methane, water vapor, and ammonia. The tops of the gas clouds in the atmosphere make up the colorful texture on Jupiter. Jupiter, sometimes called Jove, was the King of the gods in Roman mythology and the son of Saturn. Like Saturn, Jupiter has rings, though they are much smaller, fainter, and darker. Position: Fifth from Sun Distance from Sun: 778,330,000 km Jupiter Day: 9.8 Earth Hours Jupiter Year: 11.9 Earth Years Orbital Speed: 13.1 km/sec Eccentricity of Orbit: 0.0483 Satellites: 16 (plus Rings) Equatorial Diameter: 142,984 km Polar Diameter: 133,708 km Mass: 1.900e27 kg Major Atmospheric Gas: Hydrogen Saturn Saturn is the sixth planet from the Sun and the second largest. Saturn is flattened at the poles, due to a fast rotation on its axis. Galileo discovered Saturn in 1610, and was confused by its strange appearance in his telescope. Saturn is a gas planet, like Jupiter, and is large enough and far enough away from the Sun to retain its original primitive gases. Saturn info Saturn is the only planet in our solar system that is less dense that water. Saturn is well known for it's beautiful ring system.The ring system is divided into various parts, including rings and gaps. The bright A and B rings are separated by a large gap called the Cassini Division. Radial "spokes" composed of fine particles, about the size of dust specks, were found in the BRing by the Voyager. Saturn was the god of agriculture in Roman mythology. Saturn is also the father of Jupiter, the king of the Roman gods. Position: Sixth from Sun Distance from Sun: 1,427 million km Saturn Day: 10 hours, 14 minutes Saturn Year: 29.5 Earth Years Orbital Speed: 9.7 km/sec Eccentricity of Orbit: 0.056 Satellites: 18 (plus rings) Equatorial Diameter: 120,536 km Polar Diameter: 108,728 km Mass: 5.688e26 kg Major Atmospheric Gas: Hydrogen Uranus The atmosphere of Uranus is composed of hydrogen, helium, and methane. The methane in the atmosphere absorbs red light, giving the planet a blue-green color. Like Venus, Uranus spins from east to west, which is opposite from the spin of Earth. Uranus info Uranus has rings that are composed of fine dust, rocks, and ice boulders. The rings are very faint.. Uranus is named after the Greek god of the sky. Uranus was the husband of Gaia, the goddess of the Earth. Position: Seventh from Sun Distance from Sun: 2,870,990,000 km Uranus Day: .72 Earth Days Uranus Year: 84.01 Earth Years Orbital Speed: 6.6 km/sec Eccentricity of Orbit: 0.047 Satellites: 15 (plus rings) Diameter: 51,800 km Mass: 8.686e25 kg Major Atmospheric Gas: Hydrogen Neptune Neptune is the fourth largest planet in the Solar System. Neptune is a gas planet, composed of hydrogen, helium, methane, with traces of ammonia and water. The blue color of the planet is due to the absorption of red light by methane in the atmosphere. Neptune info Neptune has actually been the most distant planet from the sun since 1979 to 1999, due the fact that Pluto's orbit is highly eccentric. Pluto is now the most distant planet from Sun the again. Neptune has the stronger winds than any other planet in the Solar System. "The Scooter" is a cloud that moves around Neptune about every 16 hours. Neptune is the god of the sea in Roman Mythology. Position: Eighth from Sun Distance from Sun: 30.06 AU Neptune Day: 0.75 Earth Days Neptune Year: 164.83 Earth Years Orbital Speed: 5.4 km/sec Eccentricity of Orbit: 0.0097 Satellites: 8 (plus rings) Diameter: 49,528 km Mass: 1.0247e26 kg Major Hydrogen Atmospheric Gas: Pluto,Charon, Nix and Hidra Pluto, is the largest known object in the Kuiper belt. When discovered in 1930, it was considered to be the ninth planet; this changed in 2006 with the adoption of a formal definition of planet. Charon, Pluto's largest moon, is sometimes described as part of a binary system with Pluto, as the two bodies orbit a barycenter of gravity above their surfaces. Beyond Charon, three much smaller moons, Nix, and Hydra, orbit within the system. THE END!