Alamay’s & Sarah’s GUIDE TO THE SOLAR SYSTEM

1. Alamay’s & Sarah’s GUIDE TO THE SOLAR SYSTEM

2. THE SUN • The Sun is by far the largest object in the solar system. It contains more than 99.8% of the total mass of the Solar System (Jupiter contains most of the rest). • It is often said that the Sun is an "ordinary" star. That's true in the sense that there are many others similar to it. But there are many more smaller stars than larger ones; the Sun is in the top 10% by mass. The median size of stars in our galaxy is probably less than half the mass of the Sun. • Read more about The Sun l Sun Facts and images. by nineplanets.org

3. Mercury • Mercury is a small planet which orbits closer to the sun than any other planet in our solar system. • As well as being very hot, it features a barren, crater covered surface which looks similar to Earth's moon. •The surface of Mercury is very similar to our moon. It has a very barren, rocky surface covered with many craters. •Being so close to the Sun, the daytime temperature on Mercury is scorching - reaching over 400 Degrees Celsius. •At night however, without an atmosphere to hold the heat in, the temperatures plummet, dropping to -180 Degrees Celsius. •Mercury has a very low surface gravity. •Mercury has no atmosphere which means there is no wind or weather to speak of. •There is also no water on the surface of Mercury, it is possible however that there could be water underneath the surface. •Likewise, there is no air on the surface but it could be trapped underneath. For more info on mercury search : http://science.nationalgeographic.com/science/space/solar-system/mercury-article/

4. Venus • Venus and Earth are similar in size, mass, density, composition, and distance from the sun. There, however, is where the similarities end. • Venus is covered by a thick, rapidly spinning atmosphere, creating a scorched world with temperatures hot enough to melt lead and a surface pressure 90 times that of Earth. Because of its proximity to Earth and the way its clouds reflect sunlight, Venus appears to be the brightest planet in the sky. • Like Mercury, Venus can be seen periodically passing across the face of the sun. These transits occur in pairs, with more than a century separating each pair. Since the telescope was invented, transits have been observed in 1631, 1639; 1761, 1769; and 1874, 1882. On June 8, 2004, astronomers worldwide saw the tiny dot of Venus crawl across the sun; the second in this pair of early 21st-century transits will occur June 6, 2012. • Toxic Atmosphere • Venus's atmosphere consists mainly of carbon dioxide, with clouds of sulphuric acid droplets. Only trace amounts of water have been detected in the atmosphere. The thick atmosphere traps the sun's heat, resulting in surface temperatures over 880 degrees Fahrenheit (470 degrees Celsius). Probes that have landed on Venus have not survived more than a few hours before being destroyed by the incredibly high temperatures. • The Venusian year (orbital period) is about 225 Earth days long, while the planet's rotation period is 243 Earth days, making a Venus day about 117 Earth days long. Venus rotates retrograde (east to west) compared with Earth's prograde (west to east) rotation. Seen from Venus, the sun would rise in the west and set in the east. As Venus moves forward in its solar orbit while slowly rotating "backwards" on its axis, the cloud-level atmosphere zips around the planet in the opposite direction from the rotation every four Earth days, driven by constant hurricane-force winds. How this atmospheric "super rotation" forms and is maintained continues to be a topic of scientific investigation.

5. EARTH • Earth, our home planet, is the only planet in our solar system known to harbour life. All of the things we need to survive are provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to create a constantly changing world that we are striving to understand. • Viewing Earth from the unique perspective of space provides the opportunity to see Earth as a whole. Scientists around the world have discovered many things about our planet by working together and sharing their findings. • Some facts are well known. For instance, Earth is the third planet from the sun and the fifth largest in the solar system. Earth's diameter is just a few hundred kilometres larger than that of Venus. The four seasons are a result of Earth's axis of rotation being tilted more than 23 degrees. • Oceans at least 2.5 miles (4 kilometres) deep cover nearly 70 percent of Earth's surface. Fresh water exists in the liquid phase only within a narrow temperature span (32 to 212 degrees Fahrenheit/ 0 to 100 degrees Celsius). This temperature span is especially narrow when contrasted with the full range of temperatures found within the solar system. The presence and distribution of water vapour in the atmosphere is responsible for much of Earth's weather.

6. MARS • The Red Planet • Mars is a small rocky body once thought to be very Earth like. Like the other terrestrial planets—Mercury, Venus, and Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change in the planet's orbit. • Martian tectonics, the formation and change of a planet's crust, differs from Earth's. Where Earth tectonics involve sliding plates that grind against each other or spread apart in the seafloors, Martian tectonics seem to be vertical, with hot lava pushing upwards through the crust to the surface. • Periodically, great dust storms engulf the entire planet. The effects of these storms are dramatic, including giant dunes, wind streaks, and wind-carved features. • Water on Mars? • Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in the solar system. This water may even have pooled into lakes or shallow oceans. But where did the ancient floodwater come from, how long did it last, and where did it go? • At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist at the surface for long. There's water ice close to the surface and more water frozen in the polar ice caps, but the quantity of water required to carve Mars's great channels and flood plains is not evident on—or near—the surface today. Images from NASA's Mars Global Surveyor spacecraft suggest that underground reserves of water may break through the surface as springs. The answers may lie deep beneath Mars's red soil. • Unravelling the story of water on Mars is important to unlocking its past climate histoy, which will help us understand the evolution of all planets, including our own. Water is also believed to be a central ingredient for the initiation of life; the evidence of past or present water on Mars is expected to hold clues about past or present life on Mars, as well as the potential for life elsewhere in the universe. And, before humans can safely go to Mars, we need to know much more about the planet's environment, including the availability of resources such as water

7. Jupiter • Jupiter has a liquid metal ocean (metallic hydrogen) at its centre, surrounded by thousands of kilometres of hydrogen and helium gas. • Jupiter's famous Red Spot is in fact a storm the size of Earth that has raged for hundreds of years. • Jupiter has a thin set of rings, hardly visible, even with telescopes, from Earth • Jupiter is the vacuum cleaner of the Solar System. It sucks in comets, asteroids and meteorites which could be on a collision course for Earth. The comet, Shoemaker-Levy 9, was pulled apart by Jupiter's gravity and eventually collided with the planet in 1994. • Jupiter takes only 9 hours and 55 minutes to spin on its axis. This means a day on Jupiter is less than 10 hours long. Its fast rotation causes the planet to be squashed, being wider at the equator than from North to South. • Jupiter is the planet with the strongest pull of gravity in the Solar System. If we were able to stand on the surface of Jupiter, we would weigh three times as much as we would weigh on Earth. The only other object in the Solar System with a stronger pull of gravity is the Sun. • The mass of Jupiter is 318 greater than the mass of Earth. • Jupiter's moon, Ganymede, is the biggest moon in the Solar System. • If we were able to see Jupiter's radiation belt from Earth, Jupiter would appear as big as the Sun. • Jupiter's gravity is used to catapult space-craft on deep space missions further away. This is how the Voyager missions of 1975 managed to succeed

8. Saturn • Saturn is the second largest planet in the Solar System after Jupiter. It is so big that Earth could fit into it 755 times. • Saturn is a slightly smaller version of Jupiter, with similar, but less distinctive, surface patterns. Like Jupiter, it is mostly made up of hydrogen and helium gas. Saturn's main difference to Jupiter is the amazing set of rings that orbit it. • Saturn's rings may be particles of an old moon orbiting the planet, smashed apart in a collision millions years ago. • Saturn's rings orbit the planet at different tilts. Sometimes, they can appear like 'ears' sticking out of the planet. At other times, they are flat on when seen from Earth and are hardly visible. This shows how thin they can be. • It is believed that Saturn's rings will one day disappear. They will either disperse (spread out) into space or get sucked into the planet by its pull of gravity. This isn't likely to happen anytime soon, more than likely occurring in ten of millions of years time. • Despite its similarities to Jupiter, there is no great spot on Saturn, although the planet does have stormy weather. • Saturn is twice as far away from the Sun as Jupiter is. • Saturn's largest moon, Titan, is the only moon in the Solar System to possess an atmosphere. • Christian Huygens, the Dutch astronomer who discovered Saturn's moon Titan in 1655, also invented the pendulum clock. • It is thought that Titan's atmosphere is so thick, and its gravity so weak, that humans beings could strap on a set of wings and fly through its skies. Of course, it's too cold to survive there but it's an interesting thought! • The first sounds to be recorded from any other world in the solar system were recorded from Saturn's moon Titan by the Huygens space probe in 2005. • Saturn has such a low density (meaning that its particles are far apart) that, if there was an ocean big enough, Saturn would float on it. In comparison, Earth and Mercury would sink to the bottom quickest. • A year on Saturn would take almost thirty Earth years. However, a day on Saturn is about 10 and a half hours. • If Earth had rings that spanned as far out as Saturn's, they would reach about three quarters of the way to the Moon.

9. Uranus • After Saturn, a space-craft would have to travel 1,500,000,000 kilometres to reach Uranus. This means the planet is almost twice the distance from the Sun than Saturn is. • Uranus orbits the Sun on its side. Its south pole is pointed towards Earth. The angle of the tilt of the axis of Uranus is 97 degrees. This is probably due to an object the size of Earth smashing into Uranus during its formation billions of years ago. • Voyager 2 was the first manmade object to reach Uranus. It had previously visited Jupiter and Saturn and had taken exciting close-up images of those two planets and their moons. However, when the first pictures of Uranus from Voyager 2 were received on Earth in January 1986, scientists were disappointed to see that it was a pale blue, featureless world. Six years of waiting and all they saw were images like the one on the left! • Uranus' pale blue colour is caused by the methane in its atmosphere which filters out red light. • If we were able to see Uranus' moons orbiting the planet, they would go over and under the planet like lights on a Ferris wheel. • Like the other Gas Giants (Jupiter, Saturn and Neptune), Uranus has rings of ice and small rock particles. However, these rings are so faint, they are only visible for special scientific equipment. • Uranus has 27 moons (so far discovered) orbiting the planet. Ten of these were discovered in 1986 by the Voyager 2 mission. • A day on Uranus is a few hours shorter than a day on Earth - the planet takes 17 hours to spin on its axis. However, a year on Uranus is much longer than a year on Earth. In fact, it takes 84 years on Earth for Uranus to complete one orbit around the Sun! • Uranus was the first planet in the Solar System to be "discovered". The planets known of at the time of the discovery of Uranus were Mercury, Venus, Earth, Mars, Jupiter and Saturn. Ancient astronomers were able to see these objects without telescopes or binoculars and named them after their Gods. Uranus was discovered much later using scientific instruments, in 1781, but was still named after an ancient god (in mythology, Uranus was the ruler of the Gods) • Because of Uranus' unique tilt, a night at one of its poles lasts for 21 Earth years, during which it will receive no light or heat at all from the Sun. • Almost all of the moons of Uranus are named after characters in plays written by Shakespeare. The moons of every other planet in the Solar System are named after characters in Greek and Roman mythology. The two moons of Uranus that are not named after Shakespearean characters (Ariel and Umbriel) are named after characters in a book called "The Rape of the Lock" written by Alexander Pope.

10. Neptune • Diameter: 49,532 km / 30,779 miles • Avg. distance from Sun: 4,496,976,000 km / 2,797,770,000 miles • Number of known moons: 13 • Time taken to turn on axis: 16 hours, 7 minutes • Time taken to orbit Sun:164.8 years • Surface gravity:1.21 • Temp. at cloud tops: -200 °C / -328 °F

11. Pluto Pluto was classified as a dwarf planet on the 24th Aug 2006. Before then we thought that Pluto was the size of earth. Pluto was discovered by, Clyde W. Tombaugh .... On February 18, 1930, after nearly a year of searching

12. Thank you to • Sarah • Alamay • Miss Watton • Miss Mologen • Mr Jones • And family at home • If I have missed anyone out I would like to say sorry and Thank you.

13. Thank you for watch our guide now would you like to play are big bang game with the top prize as a galaxy bar.