KYLA CAMMILE S. LIM Grade 5 St.
Cecilia
THE SOLAR SYSTEM
The Solar System is made up of all the planets that orbit our Sun. In addition to planets, the Solar System also consists of moons, comets, asteroids, minor planets, and dust and gas. Everything in the Solar System orbits or revolves around the Sun. The Sun contains around 98% of all the material in the Solar System. The larger an object is, the more gravity it has. Because the Sun is so large, its powerful gravity attracts all the other objects in the Solar System towards it. At the same time, these objects, which are moving very rapidly, try to fly away from the Sun, outward into the emptiness of outer space. The result of the planets trying to fly away, at the same time that the Sun is trying to pull them inward is that they become trapped half-way in between. Balanced between flying towards the Sun, and escaping into space, they spend eternity orbiting around their parent star. The world solar is derived from the Latin word of sun, Sol, leading to the term solar system, or the system of the sun. The planets that orbit the sun within the solar system include Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
THE PLANET MERCURY
Closest Planet to the Sun
THE PLANET MERCURY
Closest Planet to the Sun Small World Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear almost three times as large as it does when viewed from Earth.
Because Mercury orbits so close to the sun, its heavily cratered surface can reach 427C. But without much of an atmosphere to trap the heat, nighttime temperature on mercury can plummet to -173C. One of the largest surface features on Mercury, the Caloris Basin is an 800-mile depression created by the impact of an asteroid or comet. Its one of the largest known impact craters in the solar system. Mercurys surface is marked with many so-called ray craters, features usually found in only in moons. These hub-and-spoke formations are created when a large object collides with the surface, flinging debris in all directions. Detailed images of Mercury contain a large blank area because its extremely slow rotation and proximity to the sun means much of the planets surface has never been mapped. The Mariner 10 mission was able to detail only about 45% of the surface. A new NASA mission to Mercury called MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) has begun orbiting Mercury in March 2011 to investigate key scientific areas such as the planet's composition, the structure of the core, the magnetic field, and the materials at the poles.
THE PLANET VENUS
Earths Sister Planet
THE PLANET VENUS
Earths Sister Planet The Brightest Planet 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. The dense atmosphere on Venus is 97% carbon dioxide, which creates a massive greenhouse effect that overheats the planet and obscures its surface. Clouds containing sulfuric acid, chlorine, and fluorine create acid rain that evaporates before it hits the ground. Ishtar Terra is home to Venus four main mountain ranges. The Maxwell Montes are the highest mountains on Venus; their highest peak rises about 6.8 miles from the surface. A 65-mile-diameter
depression called Cleopatra Crater is one of the ranges largest features. Aphrodite Terra is a highland area about the size of South America along Venus equator. It contains mountains, though they arent as tall as those in Ishtar Terra to the north. Sapas Mons is a large Venusian volcano. Its side features numerous lava flows, suggesting it may have formed in the same way that shield volcanoes do on Earth.
THE PLANET EARTH
The Big Blue Marble
THE PLANET EARTH
The Big Blue Marble Third Rock from the Sun Earth, our home planet, is the only planet in our solar system known to harbor 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 humanscombine forces to create a constantly changing world that we are striving to understand. Earths continents are large land masses, sometimes separated by water. Millions of years ago, the continents were likely joined as one large land mass called Pangaea. Earths crust has constantly shifted, causing Pangaea to break apart and form todays continents. The first layer consists of about 10 miles of rock and loose materials, scientists call the crust. Underneath the continents, the crust is almost three times as thick, as it is under the oceans. Traveling beyond the Earths crust, we next encounter the mantle. The mantle extends to a depth of approximately 1,800 miles, and is made of a thick solid rocky substance that represents about 85% of the total weight and mass of the Earth. Traveling still deeper within the Earth, we next would encounter the Earths outer core, which extends to a depth of around 3000 miles beneath the surface. It is believed that this outer core is made up of super-heated liquid molten lava. This lava is believed to be mostly iron, and nickel.
Finally, we would reach the Earths inner core. The inner core extends another 900 miles inward towards the center of the Earth. It is believed that this inner core is a solid ball of mostly iron, and nickel.
THE PLANET MARS
The Red Planet
THE PLANET MARS
The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planetsMercury, Venus, and Earthits 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. The polar caps have a top layer of frozen dioxide and can grow and recede Mars seasons. There is water ice deep beneath the southern cap. Unique spiral troughs form from heating and cooling during the seasons. No other planet has such structures. Valles Marineris is a huge canyon that runs roughly along Mars equator, spanning a distance equivalent to the distance between New York and Los Angeles. It was probably formed from large rifts in the planets surface that slowly eroded or fell inward over time. The Hellas Basin is the largest impact basin on Mars. It was formed when a large object struck the planets surface. The Argyre Basin was probably formed when a large object such as an asteroid or comet hit the planets surface about 3.9 million years ago. This impact basin is the second largest on Mars. Olympus Mons is the largest known volcano in the Solar System. It is three times taller than Earths tallest mountain, Everest. It is as large as the state of Arizona. Mars has two moons. Phobos and Deimos, which are among the smallest in the Solar System. They are made of carbon-rich rock mixed with ice. Scientists believe they could also be trapped asteroids.
THE PLANET JUPITER
The Giant
THE PLANET JUPITER
The Giant Jovian Giant The most massive planet in our solar system, with four planet-size moons and many smaller satellites, Jupiter form a kind of miniature solar system. Jupiter resembles a star in composition. In fact, if it had been about eighty times more massive, it would have become a star rather than a planet. The Equatorial Zone is one of the more stable regions of Jupiter, with less activity than the rest of the planet.
Jupiter has three sections of rings that are very difficult to see. Jupiters rings are small bits of dust. Meteors striking the surface of Jupiters moons kick up dust that goes into orbit and forms the rings. The planet's "stripes" are dark belts and light zones created by strong east-west winds in Jupiter's upper atmosphere. Within these belts and zones are storm systems that have raged for years. The Great Red Spot, a giant spinning storm, has been observed for more than 300 years. The four Galilean satellites; Io, Europa, Ganymede, and Callisto, are among the most interesting of all solar system bodies, particularly Io, with its active volcanism, and Europa with the possibility of a water environment friendly to life. The Galileo spacecraft explored the moons while orbiting Jupiter for eight years: 1996-2003.
THE PLANET SATURN
The Ringed Planet
THE PLANET SATURN
The Ringed Planet Saturn is similar to Jupiter, but it is much smaller. It is the second largest planet in our Solar System and it is a gas giant like Jupiter. Under the clouds of methane, hydrogen and helium, the sky gradually turns into liquid until it becomes a giant ocean of liquid chemicals. Saturn is the least dense planet in our Solar System. It is made up of mostly hydrogen and helium, which are the two lightest elements in the universe and thus make Saturn the lightest planet that we know of. This is why you wouldn't weigh as much on Saturn as you think you would because of its size. And because Saturn is so light, it does not have as much gravity. Interestingly, it is believed Saturn would actually be able to float in water because the hydrogen and helium that make up the planet are so lightweight. Because Saturn is such a lightweight planet and it spins so fast, Saturn is not perfectly round like most of the other planets. Like Jupiter, Saturn is wider in the middle and narrower near its top and bottom. Saturns beautiful rings are divided into seven distinct sections mostly of ice particles. There found braided rings, ringlets, and
spokes, dark features in the rings that circle the planet at different rates from that of the surrounding ring material. Saturn has 53 official moons and 9 provisional (unofficial) moons. The most well-known of Saturn's moons is probably Titan. It is the second largest moon in the Solar System next to Jupiter's Ganymede. Titan is larger than the planet Mercury. Some of the other moons are Atlas, Calypso, Dione, Enceladus, Hyperion, Iapetus, Janus, Mimas, Phoebe, and Tethys.
THE PLANET URANUS
The Blue Planet
THE PLANET URANUS
The Blue Planet Unusual Uranus Once considered one of the blander-looking planets, Uranus has been revealed as a dynamic world with some of the brightest clouds in the outer solar system and 11 rings. The first planet found with the aid of a telescope, Uranus was discovered in 1781 by astronomer William Herschel. The seventh planet from the sun is so distant that it takes 84 years to complete one orbit. Uranus spins on its side. It is believed that long ago a very large object smashed into this planet. The crash was so powerful that it completely changed the direction of Uranus' planetary rotation. However, a more recent theory is that the extreme tilt of Uranus' axis may have been caused by a large moon that was slowly pulled away from the planet by another large planet long ago when our Solar System was still new. It is thought that the gravitational pull of this moon moving away from Uranus may have caused it to tilt on its side. Uranus also has rings, though they don't stretch out as far as the rings of Saturn. The rings of Uranus are made up of black dust particles and large rocks. Uranus has 27 moons. Five of these moons are large and the rest are smaller. The largest moon is Titania, followed by Oberon, Umbriel, Ariel and Miranda. Some of the smaller moons are named: Belinda, Bianca, Caliban, Cordelia, Cressida, Desdemona, Juliet, Ophelia, Portia, Puck, and Rosalind.
THE PLANET NEPTUNE
The Outermost Planet
THE PLANET NEPTUNE
The Outermost Planet
Invisible to the Naked Eye The eighth planet from the sun, Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. Neptune is the smallest of the four gas giants in our Solar System. Much like Saturn and Uranus, Neptune's atmosphere contains hydrogen, helium and methane. Not much was known about Neptune until it was visited by the spacecraft Voyager 2 on August 25, 1989. Voyager 2 took many pictures of the planet, and much of what we know today about Neptune came from this single visit. These pictures show a brilliant blue planet with a few thin white clouds laced around its surface. In Neptune's atmosphere, there is a large white cloud that moves around rather quickly. The "scooting" of this cloud around the atmosphere has led it to be named "Scooter." Neptune is a very windy place. No other planet in the Solar System has winds that are as strong as Neptune's. The winds near the Great Dark Spot were believed to have reached nearly 1,200 miles per hour. Perhaps this extremely windy atmosphere contributes to the appearance and disappearance of the great dark spots. Neptune has six rings which circle the planet. These rings are believed to be fairly new. The rings are more irregular than the rings of other planets. There are areas of varying thickness throughout the rings. Neptune has 13 known moons; two of these are Nereid and Triton. Nereid is the farthest of Neptunes moons.
