why three citron

Solar system
The solar system there is about 4.6 billion years ago.
In the center of the solar system, the sun is a yellow dwarf star that produces large amounts of energy.
There are eight major planets and 100 moons in our solar system.
Mercury, Venus, Earth and Mars are small, rocky planets. Jupiter, Saturn, Uranus and Neptune are gas giants.

All the planets revolve around the sun in an elliptical-shaped path, oval.
Many of the planets of the solar system are visible to the naked eye.
Other objects in the solar system are dwarf planets, asteroids and comets.
The solar system is in a galaxy known as "The Milky Way".
It is estimated that at least a third of the 200 billion stars in the Milky Way are orbited by one or more planets.
The Voyager 1 spacecraft is made object farthest man in the solar system at a distance of about 11 billion miles (18 billion kilometers) from the sun and is still sending data to Earth.
image1Nacimiento solar system

Our solar system was formed as part of a massive nebula cloud of molecular hydrogen gas and dust about 4.6 billion years ago. In a region of this cloud conditions allowed gravity began condensation of hydrogen, until a substantial mass began to grow bigger and hotter increasingly finally this mass collapsed in on itself, forming the first stage of a star called protostar. The gravitational pull of the embryonic star caused a disk of gas and dust around them.

Over millions of years, the pressure began to build up inside the protostar, which became hotter and denser until finally nuclear fusion is initiated at its core, giving birth to the sun as we know it today. During this time the disk of gas and dust that had formed around the star had also begun to condense into bodies constantly growing. Eventually they formed the planets, moons and other objects in our solar system.

The planets of the solar system

The closest planet to the Sun is Mercury, named after the fleet-footed messenger god it orbits around the Sun in only 88 days, faster than any other planet in the solar system. Then comes Venus, known as the sister planet Earth, but under heavy clouds often found a hellish landscape with temperatures hot enough to melt lead. The third planet from the Sun is Earth, a striking blue sphere covered with oceans of liquid water and the only planet known to harbor life. The last of the rocky inner planets is Mars, which consists of a thin atmosphere of red, was once covered by oceans like Earth, but is now a desert where dust storms can engulf the entire planet.

image2A nearly 800 million kilometers from the sun, we find the first of the gas giants, Jupiter, huge in size, while more than 1000 Earths would be required to fill its volume. Saturn is the second of the gas giants and is unlike any other planet in the solar system with its spectacularly colorful rings made of dust and ice. Then comes the first of the planets known as ice giants, Uranus, this big ball of gas turquoise lies tilted on its side with freezing atmospheric temperatures of -371 degrees Fahrenheit. A 4.5 billion kilometers from the sun is the last of the planets, Neptune, a giant blue ice, where the winds in the atmosphere reach over 2,000 kilometers per hour.

Moons in the solar system

As mankind explores the space we have found that some of the moons in our solar system are equally and sometimes even more fascinating than the planets themselves. The wonderfully colorful Jupiter's moon is the most volcanically active object in the solar system, Saturn's moon, Titan has a thick atmosphere based on nitrogen producing rains liquid methane lakes on its surface. Another of Saturn's moons, Enceladus, has volcanoes that erupt with ice water and possibly has a liquid ocean under its icy surface. Then there is the world of ice in Europe, one of the fascinating moons of Jupiter, below its surface is a vast ocean of liquid water, 100 km depth, and possibly full of life.

Other solar system bodies

In the center of the solar system is the Sun, a huge ball of hydrogen and helium over a hundred times larger in diameter than Earth, and produces intense heat and huge explosions thrown overboard solar winds million kilometers space. Between the orbits of Mars and Jupiter is the asteroid belt, millions of rocks reside in this area, some as large as 60 miles (100 km) in diameter. Beyond Neptune, we reach the Kuiper Belt, where the majority of dwarf planets, like Pluto, once considered the ninth planet in our solar system, this small orbiting body around the sun at an average distance of almost 6000 million kilometers. Comets originate in the Kuiper Belt, or further away in the Oort cloud, a massive spherical cloud of icy bodies surrounding the solar system.

Life in the Solar System

Humanity often reflects whether there is life in the solar system besides Earth, and if so what kind of life? Until the mid 20th century it was thought that each planet could harbor some kind of life forms, possibly even more advanced than us. When the famous novel "War of the Worlds" by Jules Verne, was transmitted by radio caused widespread panic among listeners who mistakenly thought it was real, an indication of faith in life forms alien advanced neighboring planets in common psyche.

Of course, we now know that this is just science fiction and we are not under any imminent attack from an alien civilization on Mars or Neptune. So is there life elsewhere in the solar system other than Earth, and who are the suspects? Well, you may be surprised to learn that there are several candidates in our solar system that could harbor life.


Let's start with Mars, the planet that captures the imagination of most. Although we now know that no canals on Mars, or advanced civilizations, the scientists involved in the Viking landings still hoped to find signs of life on the Martian surface. Viking 1 landed on Mars in June 1976 and samples of Martian soil were analyzed, but found nothing. Subsequent missions have also found no sign of life, but there is hope, and that is underground. The reason for this theory is that, surprisingly, methane is present in the atmosphere of Mars, and a way of methane can be produced biologically. In the summer months the presence of methane on Mars rises dramatically, giving more credence to the idea that there are organisms that live below the surface, possibly around thermal vents.

There are two interesting moons around Saturn, it could possibly support life. Both are very different from each other, are Enceladus and Titan. Enceladus is a small icy world with a slightly larger than Texas area, but beneath the surface is believed to be an ocean of salt water. How can it be hot water in such a cold area of ​​the solar system? Well, the enormous gravitational force of Saturn pushes and pulls the small moon, inside heating and melting the ice beneath the surface. If so, this could provide an environment for microorganisms or some other forms of life.

Enceladus neighbor, and 600,000 miles away, this one of Saturn's moons, Titan. This moon is unique in the solar system, because it is the only one with a significant atmosphere, and what is even more surprising is that its atmosphere is mostly nitrogen, like our own planet. Even more surprising it is that it is the only object in our solar system other than Earth with large areas of liquid on its surface, not for water, but of liquid methane. Methane on Titan acts as the water on Earth, there are methane clouds that produce methane rain and lakes of methane. Titan is often compared with the primordial Earth, but unfortunately it is in the freezer, with surface temperatures around-179C (-290F). It is still possible that there microbial life with breath hydrogen instead of oxygen.

Finally we come to an icy moon orbiting Jupiter, called Europe. It is believed that the moon, only slightly smaller than Earth's moon, has the best chance of life throughout the solar system. The gravity of Jupiter produces an enormous heating within Europe, heating inside and producing a saltwater ocean, 62 miles (100 kilometers) deep. There may be double the amount of liquid water in Europe from which there is on Earth. It has been speculated that Europa's ocean could be full of life, not bacteria, but also of complex organisms that can swim in the warm water. 2025 NASA hopes to land a probe on the surface of Europe, which in turn melt the ground and investigate the ocean for signs of life, maybe then we'll find out that we are not alone in the solar system.

Our galaxy and the universe

In the context of the size of the universe, the earth, and indeed the entire solar system it is negligible. Our sun is just one of 200 billion stars in our galaxy, the Milky Way, and is just one of more than 100 billion galaxies in the known universe. The solar system exists on the edge of our galaxy, far from downtown, where there is a super-massive black hole which has 4 million times the mass of our sun. The Milky Way is actually a giant among galaxies, covering 100,000 light years across, and there are 30 galaxies in our "neighborhood" of which only Andromeda is bigger.

The best explanation we have of how the universe was created is the theory of the Big Bang. about 14 million years a super-dense mass ago, billions of times smaller than a proton began to expand, and eventually created the stars, planets and galaxies we have today in the universe, indeed still it is expanding. It is not known how the initial mass came into being.

Statistics of solar system

Diameter of the Solar System: Unknown (possibly 2-3 light years)
Distance from the center of the galaxy: 25.000 light years
orbital period: 250 million years
Age: 4.6 billion years
Planet Number 8
Number of dwarf planets 5
Number of moons: 173
rocky planets: Mercury, Venus, Earth and Mars
Gaseous giants: Jupiter, Saturn, Uranus and Neptune
dwarf planets: Ceres, Pluto, Haumea, Makemake and Eris
closest planet to the Sun: Mercury (58 million kilometers)
Farthest planet from the Sun: Neptune (4.5 billion kilometers)
farthest from the sun human object: Voyager 1 (18 mm km)
largest planet, Jupiter (diameter 142.984 km)
smallest planet: Mercury (4879 km diameter)
Largest Moon: Ganymede (5262 km diameter)
Moon smallest: S / 2003 J 9 and S / 2003 J 12 (diameter 1 km)
Mayor planetary gravity: Jupiter (20.87 m / s2)
Mayor planetary density: Earth (5,515 g / cm3)
Largest planetary mass: Jupiter (1.8987 x 1027 kg)
Major global volume: Jupiter (1.4255 x 1015 km3)
Lower planetary gravity: Mars (3,693 m / s2)
Low density planet Saturn (0.7 g / cm3)
Less planetary mass: Mercury (3.3022 x 1023 kg)
Lower global volume: Mercury (6.08272 x 1,010 km3)

Natural disasters
Image25

What is a natural disaster?
The definition of natural disaster is any catastrophic event caused by nature or natural processes of the earth.

The severity of a disaster is measured in loss of life, economic loss, and the ability of the population to rebuild. The events that occur in unpopulated areas are not considered disasters. Thus, a flood in a desert island would not count as a disaster, but a flood in a populated area is called natural disaster.

All Natural disasters cause loss in some way or another. Depending on the severity, any number of lives can be lost due to natural disasters. The collapse of buildings or trees, freezing, being swept away by avalanches or heat stroke are just some of the deadly effects of such disasters. Some disasters cause more loss of other lives, and population density affects the death toll as well.

Then there is the loss of property affecting sectors of the population, transportation, livelihoods and livelihood. Saturated salt water after tsunamis fields take years to be able to grow again. Houses destroyed by floods, hurricanes, cyclones, landslides and avalanches, volcanic eruptions and earthquakes often are irreparable, or take a long time to become livable again. Personal items, household goods, vehicles and documents are also destroyed after many natural disasters.

The natural disasters that really affect people around the world tend to be more intense as the years pass. The frequency of earthquakes, mega storms and heat waves have increased significantly in recent decades. The population density in the areas that are affected by floods, cyclones and hurricanes means that, in fact, more lives are lost.

In some areas, people are unprepared for the eventuality of disaster, and shelters are built for hurricanes and tornadoes, however, the loss of property remains a problem, and the prediction of many different disasters natural is not easy.


Scientists, geologists, and storm watchers work hard to predict disasters and prevent greater damage. With all the technology available has been made easier to predict severe storms, blizzards, hurricanes and other natural disasters related phenomena. But there are still natural disasters that occur unexpectedly, such as earthquakes, forest fires, landslides and even volcanic eruptions.

Sometimes, there is a time warning, but often is very short and with catastrophic results. In areas that are not used to be affected by disasters such as floods and hailstorms they may be affected in an extreme way if they appear suddenly.

image26Sin Despite the many natural disasters around the world, mankind has shown incredible resilience. When an area or country is seriously affected by a natural disaster, the reaction is always of solidarity and support. There are organizations created with the main objective to be prepared for natural disasters. These groups work to rescue a global and local level. Apart from those who have chosen to relief when disaster strikes, many people take a step forward and voluntarily, what really makes a difference.

People help by donating items, time and skills in order to help those affected by natural disaster. Celebrities often go to great lengths to raise money through concerts, marathons and visiting the affected areas. People have also shown that they can rebuild their lives and start again, but the trauma is an inevitable effect after a natural disaster.

It is clear that natural disasters are part of life as we know it, however, science is doing everything possible to predict, making aid more quickly to arrive, and people are learning to rebuild their lives in areas most safe.