Search Any Information...

Custom Search

ADD2


Thursday, February 18, 2010

Where are the Worlds Coldest Places ?

The Coldest temperature are recorded in winter in Antarctica , In July 1983, Russian scientists measured a new record low of 89.2 C.

Very cold temperature have been recorded in Siberia :- -68 C at Verkhoyansk in 1982.This place holds the record for the greatest temperature range : from a coldest winter temperature of 68C to a hottest summer temperature of 36.7 C. The Arctic ‘cold pole’ is some way from the North Pole because of the surrounding Arctic Ocean. Seas have a moderating effect on the climate of coastal areas.

Where is the Longest reef in the world ?

The Great Barrier reef, off the nrrth – east coast of Australia , is the world’s longest coral reef. It stretches for over 2000 kilometers from near Papua to the centre of the Queensland coast.

The Great Barrier Reef lies between 45 and 65 kilometers off the Australian coast. In the north it is only 15- 20 kilometers wide, but in the south the reef area extends up to 325 kilometers out to sea.

Which Volcano destroyed an ancient Roman Town?

Mount Vesuvius rises above the Bay of Naples in southern Italy. In AD 79 this Volcano erupted and buried nearby Pompeii. The Volcano had been dormant for 800 years. Few people realized it was a volcano .
On 24 August, AD 79, Mount Vesuvius suddenly erupted . For 3 days , Pompeii,was bombarded with pumice and ash. About 16,000 people died.

Where is the Worlds greatest mountain Range ?

The greatest mountain range on land is the Himalaya – Karakoram Range to the north of India . It has the most of the world’s highest peaks.

In the Himalayas, on the border of Nepal and Tibet, is Mount Everest , the highest mountain on land; 8848 meters high. The height of Mount Everest was discovered in 1852. It was named after Sir George Everest, the Surveyor – General of India at the time. The andes of South America are a longer but lower mountain range .

Where can you see over 1500 million years of rock strata ?

The Colorado Desert in the south – west of the USA has layers of rock which have formed over a period of about 1600 million years. The river Colorado and its tributaries has sliced these layers in the Grand Canyon and other nearby canyons.

The grand Canyon area is area is the only place on earth where geologists can study so many layers of undistributed rock and an almost perfect sequence of fossils. The ‘Granite Gorge ‘ at the bottom of the Grand Canyon is cut into rocks that from the base of most of North America .

Where is the earth’s crust being formed ?

New material is added to the Earth’s crust by volcanoes. Much of the lava is molten material from the part of the Earth called the mantle , which lies beneath the solid crust. Some volcanoes are found on land , but many are located deep beneath the oceans where lava flows onto the seabed.

Most scientists believe that the area of the earth’s surface remains the same. So while material is being added to the crust at the junction of some plate, it is being lost at the junctions of others.

Why do Sand Dunes move across Deserts ?

Only about one- fifth of hot deserts are covered with sand. Strong winds often blow in deserts. Because deserts are dry and so not have any vegetation, loose sand can be driven along by wind. The constant movement of sand from one side of a dune to the other moves the dune .

Deserts are probably getting bigger because there is less rain. Also, strong winds move sand further out cover the neighboring land. Bad farming has also led to the soil being worn away, creating deserts.

Why is a Snowflakes made up of crystals ?

When water vapor cools, it usually condenses into water droplets . In very cold air the water vapor condenses directly into ice crystals, and these crystals may cling together to make a snowflake.
The temperature of the cloud must be cold enough for ice crystals to form straight from water vapor. The shape of now crystals varies according to the temperature and humidity of both the air in which they form and the air through which they fall. So it is not surprising that no two crystals are alike . ‘Dry’ snow falls in cold, dry conditions . It has small crystals and blows into snowdrifts easily. ‘Wet’ snow forms when the air is moist and warm enough for the crystals to bond together

Why so we see rainbows ?

When sunlight passes through raindrops it is slightly bent. Sunlight is mixture of color – what we call a spectrum of colors. The raindrops bend some colors more than others, so they are separated out to make the colors of the rainbow.

Sunlight has to pass through the raindrops at a low angle for the colors to show as a semicircular bow. This is why you see rainbows most often after showers in the early morning or late evening , and not at midday. From an aircraft or a mountain top you can sometimes see a rainbow below you as a complete circle.

Why do trees get struck by lightning ?

When lightning flashes from a cloud to Earth, it takes the easiest path. It is attracted to the highest point in the area , and this is often a damp tree.
A lightning flash begins with a downward ‘leader stroke ‘. Air is very resistant to electricity, and the leader stroke is attracted to trees and high buildings. A tree offers a low resistance route to earth . tall buildings also attract lightning

Hail is made up of layers of ice . This is because a hailstone has risen high into the coldest part of a storm cloud again and again.

Hail is made up of layers of ice . This is because a hailstone has risen high into the coldest part of a storm cloud again and again.

Each time it rises , another layer of ice freezes around it until the hailstone is so heavy that it falls to earth. For a hailstorm to occur the top of the cloud must be colder than freezing level.

Why does thunder Follow lightning ?

Lightning is a huge spark of electricity . thunder is the sound the air makes as it is suddenly heated up by lightning . they both happen at the same time , but as light travels faster than sound , we see the lightning first and then hear the thunder.
Thunder is caused when lightning heats up the molecules of air along its path. The heated molecules expand , collide with cooler molecules and set up sound waves . Light travels very quickly, at about 300,000 kilometers per second. Sound is slower , traveling at about 20 kilometers per minute .

Why is Sea Water Salty ?

Sea water contains many minerals . They have all been washed out of the land and carried to the sea by rivers or glaciers. When sea water evaporates , these minerals remain in the sea and become more concentrated . This makes the water salty. The saltiest sea of all is the dead Sea.

Salt (sodium chloride ) makes up about 85 percent of all the minerals in sea water. The saltiness of deep sea water is fairly constant , but near the surface it varies from place to place . It is low where lots of fresh water is added from rivers.

Why Does it get Colder as you Climb a Mountain ?

As you climb up a high mountain the air gets colder. You may be a kilometer nearer the Sun., but the Sun is still 150 million kilometers away !

The Sun heats the Earth, and it is the Earth that heats the air .the Sun’s energy arrives as shortwave radiation, which is easily absorbed by the sir. There is more air to absorb the heat near the Earth’s surface than higher up . So the higher you go, the colder it gets .

Why are there coal , Seams , in the Antarctic ?

Coal is a rock made of the fossil remains of the plants . the icy Antarctic has very few plants now ; however , when these coal seams were formed , there must have been plenty of plants, and the climate must have been warmer .

The coal seams of the Antarctic were formed about 250 million years ago when Antarctic was part of the super continent , Pangaea.

When were the First Maps Made?

Simple sketch – maps were probably drawn before people could write , so maps may be older than written history. The oldest surviving map was drawn on a Babylonian tablet about 2300 BC.

An ancient map was found at Gar-Sur, nearly 400 kilometers north of Babylon. It shows mountains and a river (probably the Euphrates) flowing through a delta. Scientific map – making began with the Greeks.

When did the Alps Form ?

The Apls are made mainly of rock layers which were uplifted and folded about 25 million years ago.
The Apls are part of a series of fold mountains stretching through Europe and the middle East to the Himalayas and other mountains of Asia . they are the result of the movement of continents since the break-up of the super continent Pangaea. Africa and Eurasia drifted eastwards and rotated towards each other . Sediments in the ocean floor between these continents were compressed , folded and uplifted.

Which Travels faster ---- Light or Sound ?

Nothing is faster than light . it travels at 300.000 kilometers a second . Sound is slower – ‘only’ 330 meters a second ! you can judge this difference in speed during a thunderstorm. Then , we see an electrical charge in lightning , and hear it in thunder. Count the seconds between seeing the lightning and hearing the thunder. Each second equals 330 meters ! And when you count only 2 or 3 seconds , the storm is very near.

How does an eclipse of the sun happens ?

As the moon goes around the earth, so the earth goes around the sun . An eclipse happens when the moon comes between the Earth and the sun, which gradually disappears. How long it takes depends on the positions of the Earth, the sun and the moon, and the distance of the moon from the earth. Total eclipses are visible only in some parts of the world, so although they are fairly frequent , one person may not see all of them.

What is the difference between Planets and Satellites ?

Planets are heavenly bodies which orbit (travel around ) the sun. They do not have their own light , but reflect light from the sun.

Satellites are also heavenly bodies, but much smaller than planets , which they orbit in the same way as planets orbit the sun. Satellites too, reflect light from the sun. Except for Mercury and Venus , all planets have satellites. Earth’s satellite is the moon.

Which Planets can we see with the Naked Eyes ?

We can see Mercury , Venus, Mars, Jupiter and Saturn. Mercury is very near to sun . Visible at sunset and dawn, it is swathed in a dense atmosphere. Mars has ice – caps similar to those on Earth and canals furrowing its surface .
Jupiter , the giant of the Solar System, is picked out by red and yellow stripes and a big red blot. Most of us known Saturn because of its rings – but these cannot be seen with the naked eye.

What is a Falling Star?

Falling ‘stars ‘ are not stars at all !! They are little stones which come from outer space , becoming white hot as they enter the Earth’s atmosphere.
If they are not on fire , they will be difficult to see – they only weigh three quarters of a kilogram at most !Are falling stars unusual ? Not at all. It is estimated that each day at least 24 million enter the atmosphere – enough for 24 million wishes!!

What is the Green House Effect ?

The earth is warmed by the sun and in return gives out heat into space . This ‘exchange ‘ happens in the atmosphere , allowing the rays of the sun to pass and the Earth’s heat to return from its source. If the atmosphere is polluted , the rays of the sun can pass, but because the Earth cannot return enough heat through the atmosphere , the balance between heat coming and heat going is altered and the earth’s temperature increases.

What is Lightning ?

In the air , there are millions of particles with positive and negative electrical chanres .
When the big storm clouds gather, the charged particles become more numerous and concentrated, becoming stronger and stronger, until a spark shoots across the space in between --- lightning !!
Lightning can happen within a cloud , between two different clouds and also between a cloud and the ground.

How do we get Hail?

When particles of sleet form at a great height, they then fall through clouds carrying drops of rain. So, the sleet particles are enlarged by the rain gathering around each one and freezing.
Or, water drops in a cloud are carried up high into zones where the lower temperature freeze them. Hailstones – the balls of ice which fall – can be small as a pea, or as large as an orange !!

Why is the Sky Blue?

How is it that we see the sky as being blue, when air is colorless?
It s because of the dust in the air. The light of the sun Shines through the dust , which acts as a filter, allowing only blue rays of light to rise above.
But when the air is polluted with too much harmful dust , this filters the rays more than needed and the sky is no longer blue. And where pollution reaches high levels, a blue sky is only a memory.

What are Breezes?

Breezes are light winds, maximum Force 3, caused by differences in temperature between the sea and land. Both become warm and cold at different speeds – slowly for the sea, quickly for the land.

By day , the air over the land rises up, and in its place comes the fresh air from above the sea. At sunset, the land is cool: so, the air above it is drawn to the sea, where the warmer air rises , making room for the cool air.

What is a Drought ?

Drought is a lack or scarcity of rain which goes on for an unusually long time.
The rainfall of a region or locality is calculated on the amount of rain which falls during a year __ including the number of days with rainfall of a certain type ---rain;snow and hail.
With each region having its own records of rainfall , people can measure if and when this is scare enough to become a drought.

What is a rainbow ?

A rainbow is seen when it is raining and sunny at the same time.
When it rains , the rays of the sun hit the raindrops , splitting then into seven colors and bending them as it passes through to form an arch of colored light. From the outside (or east ), the colors are –Red , Orange , Yellow, Green, Blue , Indigo and Violet.
As for the gold at the end of the rainbow, nobody’s found it yet !

Monday, February 15, 2010

What is a Climate ?

The Climate is the whole range of weather conditions found in a region or area during the course of a year.

The elements which make up the climate are –temperature ,winds , atmospheric pressure (measured by barometer),Humidity and rainfall.

We also take into account the geographic features which have a bearing on these elements --- such as latitude, distance from the sea and exposure to the sun.

What causes the Hurricane ?

Hurricanes , cyclones , typhoons … all three words mean more or less the same – a formation of the oceans of zones of low pressure which causes changes of position in the air, generating violent winds which often approach speeds of over 120 kilometers an hour.

Fortunately for us , light tremors of the ground warn us of hurricanes approaching , and this usually helps us to predict their arrival a few days beforehand.

How many Oceans are there ?

The oceans are huge masses of water between continents – but all linked together to form one mass. There are three. The most easterly is the Pacific Ocean, covering about 100,000,000 square kilometers and the Indian Ocean around 75,000,000 plus the 2 glacier seas of the Arctic and the Antarctic, covering 70 percent of the Earth’s surface , altogether.

How deep is the Sea ?

The Pacific Ocean is the deepest , with a minimum depth of 4,050 meters , maximum 11,030. Next is the Indian Ocean --- minimum 3,900 meters, maximum 9,200 and the Atlantic – minimum 3,300, maximum 9,200. The maximum depth of Artic Ocean is 5,500 meters , then the Mediterranean Sea with a maximum depth of 5,120 meters , minimum 1,000. Bottom of the deep sea league is the Baltic – minimum depth 460 meters and the North sea 90-100 meters

Why is the Sea Salty ?

All the water contains salt. The taste depends on the quantity and the water in which it is dissolved. In the sea, the saltiness depends on the temperature, the rivers flowing into it and the currents, With high temperatures, water evaporates and the salt gets very concentrated. River being clear water – so a sea which has a lot of river water has less salt than one where few rivers flow. The currents mix the water and so dilute the quantity of salt.

How does A lighting conductor work ?


A lighting conductor is a metal pole which is set into the ground , going up the side of a building to the roof. In a storm, the air is full of electricity --- charges of this electricity are what we call lightening . It is attracted to the points of objects – so the tip of the conductor attracts the lighting , taking it down to the earth, and the building is not struck. The lighting conductor was invented by the American Benjamin Franklin in 1752.

When did man first see the Earth ?



On 16th July 1969, The American spaceship Apollo II was launched towards the Moon.

And on the 21st day of Space Mission American Astronaut , Neil Armstrong set foot on the Moons surface at the Bay of Tranquility.

In front of their television sets, Earth-Men could share in the emotions and the excitement, seeing before the eyes the earth seeming to Float against the black background of cosmic space.

How long did it takes for the earth to form?



Millions and Millions of years ago, there was one vast continent in the Southern Hemisphere which scientists call ‘Gondwana’.

Africa , South America, Australia and India – all Gradually broke away from it and began moving northwards. The mountains of the Himalayas formed where India joined on to Asia.

And the only past of Gondwana which still remains is the Antractic.

Where do we find the worlds largest forests ?



If they were put all together , the forests would take up more than a quarter of the Earth’s surface!

Asia has the most , followed by South America, North America , Africa , Europe, then Australia.

The Asian jungles and the Amazon forests are largest, with thousands of different types of animals and plants – but so dense and thick, that even with all the methods man has at his disposal , they cannot be conquered.

Which are the highest Mountains On Earth?

The highest mountain is Everest (8,848 metres).Dhaulagiri, Nanga Parbat, Kanchenjunga and Annapurna, also in the Himalayas between India and China , are around 8000 meters. In Argentina the Aconcagua is 6960 meters, with others over 6,000 meters. Alaska’s Mckinely is 6,194 meters high; Kenya’s Kilimanjaro is 5,199 meters. In Antarctica , Vinson is 5,140 meters. Highest in Europe is Mont Blanc (4810 meters)

Thursday, February 11, 2010

What is the Grand Canyon ?


The Grand Canyon in Colorado, U.S.A is a series of huge gorges ‘dug out’ bu the waters of the Colorado River shushing through a narrow tract joining Little Colorado to Lake Mead.

Over 2,000 meters deep, up to 25 kilometers wide and 450 kilometers long, the Colorado began this canyon five or six million years ago. And as well as tourists, it attracts the adventurous types who ride down it in rubber dinghies.

Monday, February 8, 2010

Where is the Coldest Place On Earth ?

The Coldest place on earth is the Antarctic, where the temperature can often go as low as 78 Degree below zero , Celcius!Then somes Siberia woth 50.1 D Celsius below zero.
The coldest cities in Europe , based on average temperature during the coldest months, are Archangel in Russia with 13.3 D Celsius below zero, followes by Montral, Canada, with 10.6 D , Veijing with 4.7 and Tashkent with 1.3 D Celsius below zero.

What is a Temperature Range ?

A temperature range is the difference in temperature , It can be daily , between day and night ; monthly , between the hottest and coldest day , or a yearly temperature range between the coldest and hottest months .

All the differences in the temperature increases with the latitude and distance from the sea. The Sahara desert , for example , has a daily temperature range , beacue it is so hot by day , yet very cold at night.

How is there a Day and a Night ?

As the earth travels around the sun, so it spins on its own axis.
In 24 hours it takes to spin on its axis is called a ‘day’ but , of course , this includes the night hours , too. And night – time varies with the seasons and also with the latitude.
At the Equator it always lasts twelve hours , and , as we get towards the Poles the duration varies until, at the Poles themselves, the nights are six months long!

How Big is the Earth?

The Earth is slightly flat at the North and South Poles. So its measurement around the equator is 40,076, 594 kilometers, whereas, vertically around the Meridian line of longitude , it is 40,009,152. Its surface covers 510,100,000 square kilometers 149,400,000 land and 360,700,000 oceans, The distance from the earth to the Sun is 149,509,000 kilometers , whereas between the earth and the Moon it is ‘only’ 384, 365 kilometers.

How is the Earth Made Up ?

If we could cut it in half , we would find the Earth is rather like an onion , with various layers around a central core.This core , the nucleus, has a radius of 3,500 kilometers.
Around the nucleus is the ‘mantle’, 100 kilometers thick, then the Earth’s crust on which we live.
The various layers are composed of different materials, the temperature increasing the nearer they are to the nucleus.

What is “The Fire Belt”?

The Earth’s crust if formed by enormous layers. Between one layer and another, there is a space which makes a clearing for the mot materials coming from the depths of the earth.

That is why, along these breaks in the Earth’s crust , we find many Volcanoes.

All around the Pacific Ocean, there are a series of breaks, and therefore a series of volcanoes are so many that is is called “The Belt Of Fire “.

What is a Volcano?

In the depth of the earth, the temperature is very high. Rocky substances there collect in huge underground ‘fireplaces’, spreading out and rising up through cracks in the Earth, like natural chimneys, until they come out together through an openings in the Earth’s crust to form a volcano.

An eruption happens when the hot materials continue to burn, rising up the length of the ‘chimneys’ and exploding through the surface.

What is the Age of the Universe?

The galaxies in the universe appear to be expanding away from each other. If we work backwards, we find that they were close together between 15,000 and 20,000 million years ago. In thisWay the universe began ?

Most astronomers agree that the galaxies are flying away from some explosion that ‘created ‘ the universe. But it is impossible to say why this explosion, or ‘Big Bang’, occurred.

After the ‘Bang’, matter was formed in the tremendous heat, and galaxies were created.

What is a Pulsar ?

After a supernova explosions , all that is left of a star is very hot ball of matter a few kilometers across, spinning at a tremendous rate. It sends out beam of light that is seems to ‘pulse’ on an off. It is called a pulsar.

These remains are the shrunken core of the original star, at a temperature of millions of degrees. One of the strongest pulsars is the star at the centre of the Crab Nebula, which rotates 30 times a second. The fastest known pulsar , however rotates 642 times a second.

When Did the First Spacecraft land on another world?

Soviet spacecraft made the first direct landings on the Moon on 13 September 1959. Venera 3 reached Venus in March 1966; and Mars 2 landed on Mars in November 1971.

The First American craft to reach another world was Ranger 7 , which struck the Moon on 31 July 1964. The first Spacecraft to land people on the Moon was Apllo 11, on 16 July 1969. The Photographs shows astronaut Buzz Aldrin on the Moons surface. Venera 4, which landed on Venus on 18 October 1967, was the first probe to send back information from the surface of another planet.

When did the First Man fly in to the space?

The Soviet cosmonaut Yuri Gagarin made the first orbit of the eart on 12 April 1961 in a Vostok spacecraft. The trip lasted 108 minutes and landed within 10 kilometers of the planned descent point.

The first orbit by an American was made by Jhon Glenn in a Mercury spacecraft on 20 February 1962. Glenn was not the first American in space. For Alan Shepard had made a ‘space hop’ on May 5 1961. He reached an altitude of about 180 kilometers before returning to Earth. On 6 August the Soviet Cosmonaut Herman Titov made 17 orbits of the Earth
.

What is a Milky Way?



If the night is very clear and there is no moon, a hazy band of light can be seen running through some of the constellations. This band is caused by distant stars, which cannot be seen separately with the naked eye.

The Milky Way is the proof, to the naked eye, of the shape of the Galaxy in which the Sun is located. If the Galaxy were spherical in shape, we should see distant , faint stars in all the directions in the sky. The Milky Way effect suggests that the Galaxy must be flattened in form. Like many other galaxies that can be observed with powerful telescopes.

What is a Milky Way?



If the night is very clear and there is no moon, a hazy band of light can be seen running through some of the constellations. This band is caused by distant stars, which cannot be seen separately with the naked eye.

The Milky Way is the proof, to the naked eye, of the shape of the Galaxy in which the Sun is located. If the Galaxy were spherical in shape, we should see distant , faint stars in all the directions in the sky. The Milky Way effect suggests that the Galaxy must be flattened in form. Like many other galaxies that can be observed with powerful telescopes.

How big is the Sun ?

The Sun measures 1,392,530 kilometers across , or 109 times the diameter of the Earth. Over a million Earth could be squashed into the Sun’s globe. If the Sun were the size of a football, the Earth would be only two millimeters across.Although the Sun is enormous compared with the planets, it is much smaller than many stars. The bright reddish star Betelgeuse in the constellation of Orion is large than the orbit of the planet Mars, or about 300 times the Sun’s diameter

Why is setting Sun Red?

The Earth’s atmosphere is like a pare red filter, and makes the light coming from space turn reddish.

But an object which is very low in the sky has to shine through much more air than one high in the sky. This means that its light passes through more of this red filter, and its tint is deeper. This is the cause of the ‘red’ evening sky.

Why does the Sun keep Shining ?

Even the tiniest object contains millions of atoms. Each atom contains much tinier particles still. Inside the Sun, atoms are being pulled to pieces and put together again in a different way. This gives out heat, and keeps the Sun Shining.

The sun is made up of 90 percent hydrogen atoms, about nine percent helium atoms and one percent other elements such as oxygen and nitrogen. In its centre hydrogen atoms are reassembled as helium atoms, giving out a burst of energy.

Why do Meteors Occur ?



A meteor is a streak of light high up in the atmosphere. It occurs when a tiny solid object plunges through the air at a speed of many kilometers per second. The body is burned up by the friction, leaving a white hot trail.

Before entering the earth’s atmosphere, those bodies are called ‘meteoroids’. They orbit the sun like planets some on their own, others in long swarms. If the earth’s orbit passes through one of these meteor swarms, a meteor shower is seen.

Why do Eclipses of the sun Occurs?



The Sun is about 400 times the diameter of the Moon, but it is also 400 times as far away from the earth.This means that both bodies look about the same size in the sky when seen from the Earth.

If the moon passes in front of the Sun , it can block out the brilliant disc, so that the faint surrounding ‘corona’ can be seen.The beautiful corona can only be seen at new moon , during a total Eclipse.

Why Does a Comet have a Tail?



A comet is a crumbly body of rock and ice only a few kilometers across. When it passes near the Sun and becomes hot , the ice turns into gas, and dusty fragments are thrown out into space. Clouds of particles flying out from the Sun (the solar wind) push back this gas and dust to form the comet’s tail

The finest tails are formed by comets that have passed the sun only a few times. These can be millions of kilometers long , but are also very thin. In 1910, for example, the earth passed harmlessly through the tail of Halley’s Comet.

Why do so many Comets appear Unexpectedly?



Most of the comets take thousands or even millions of years to go round the Sun, and their orbits are so elongated or ‘eccentric’ that they travel far beyond Pluto.

Very few become bright enough to see until they are as close to Mars. That is why some comets appear without warning every year. Not all comets are surprise visitors. The famous Halley’s Comet , for example , has a period of 76 years and has been observed regularly since 239 BC. It will be seen again in 2062.

Why where the Asteroids Formed ?



The asteroids consists of countless thousands of tiny planets left over from the Solar Systems early history, when the Sun and Planets were being formed. Most of them can be formed in the wide gap between the orbits of Mars and Jupiter.

In the early days of the Solar System, space must have been quite thick with bodies like these. Gradually, though, they collided with each other and combined together to form the major planets. The largest asteroid , Ceres , is 100 kilometers across but most asteroids are quite small.

Why are the Giant Planet Gaseous ?

The Sun and the Planets of the Solar System formed from a huge cloud of gas and tiny solid particles about 4600 million years ago. Small planets like the Earth lost a lot of Hydrogen into space, but the giant planets kept all of theirs.

The pull of gravity of the giant planets is much stronger than that of the Earth. A person standing on Jupiter (supposing it had solid surface) would feel three times as heavy. This pull of gravity prevents the hydrogen from escaping into space. Hydrogen makes up about 90 percent of giant planets.

Wednesday, February 3, 2010

Why does Saturn Have Rings?



Nobody knows this for sure.The rings are made up of countless pieces of rocks and ice a few centimeters across. They could be the remains of a satellite, or moon,that broke away many millions of years ago.

Saturn’s ring system is about 22 times the diameter of the Earth, but it is only a few kilometer thick. The particles are like a blizzard in orbit around the planet’s equator.

Why is Venus So Hot?



The atmosphere of Venus is about 90 times as thick as our own. Although it is always cloudy, enough sunlight breaks through to heat the rocky ground during its four – year ‘day’. The thick atmosphere acts like a blanket and holds heat in.

The middy temperature is 480 Degree C, as hot as an oven turned fully on. Venus could not support life as we know it. The clouds consists of concentrated sulphuric acid!

Why is MARS red?


The rocks on the surface of Mars contain iron, which has turned to a kind of rust.This red, dusty material covers the planet’s surface and is sometimes blown into huge dust storms.

On Mars, the ‘red Planet’, dust is so fine that it hangs in the thin air as a permanent haze, causing the sky to be pink rather than dark blue. Sometimes the surface of Mars disappears from sight beneath clouds of dust raised by Martian winds.

Why is there no Life on the Moon?



The life – forms that are familiar to us need air and water, as well as protection from some dangerous rays sent out by the Sun.

The Moon has no atmosphere, no water on its surface , and is completely exposed to space. Also the temperature at midday is higher than that of boiling water. To find out if any living organisms built special chambers. These copied the Moons conditions exactly. Even simple bacteria died.

Why does the Moon Wax And Wane ?



The Sun can shine on only one half or hemisphere of the Moon.As it orbits the Earth every month, our view of this half changes.
At New Moon this half of the Moon is turned away from the earth, and cannot be seen, while at Full it is turned towards us.The time as the moon grows from New to Full is called ‘waxing’. After Full, the Moon ‘wanes’ or shrinks to invisibility once more.

What is the difference between a Planet and a moon?

A planet is a dark body orbiting a star. All the planet in the Solar System reflect light from the sun. A moon (or satellite) also shines by reflection, but it revolves around a planet.
Of the nine planets, only Mercury and Venus have no known satellites.Spacecraft have helped to discover 16 satellites. Spacecraft have helped to discover 16 satellites around Jupiter.Saturn has the largest satellite in the Solar System, Titan.

Why do the planets Revolve Around the Sun ?

If the planets did not move , the sun’s pull would drag them inwards. But if they moved too quickly, they would fly off into space. The closer a planet is to the Sun, the faster it must move.

The planets all move in the same direction. They were probably formed from the same spinning cloud of material that produced the sun. At birth, the Sun would have been spinning on its axis in a few hours. The cloud’s slowed it down to its present 25- day period.
Apart from Venus and Uranus , all the planets spinning anti clockwise direction too . Venus spins very slowly backwards, while the axis of Uranus is titled right over , so that it spin on its side.

When was earth formed ?

The oldest rocks found so far are thought to be about 3850 million years old – so the Earth had a solid crust by then . Some meteorites and piece of Moon rock are probably 4600 million years old, so scientists think that the earth formed about 4600 million years ago.

Scientists measure the Earths age by studyting the rate of decay of radioactive elements with special equipment . This technique is called carbon- dating .

When was earth formed ?

The oldest rocks found so far are thought to be about 3850 million years old – so the Earth had a solid crust by then . Some meteorites and piece of Moon rock are probably 4600 million years old, so scientists think that the earth formed about 4600 million years ago.

Scientists measure the Earths age by studyting the rate of decay of radioactive elements with special equipment . This technique is called carbon- dating .

Monday, February 1, 2010

When was sugarcane introduced to Europe ?



Sugar – making started in India about 3000 BC. Alexander the Great took samples home to Greece . By the 8th Century, Arabs were making sugar in Spain and France.

Christopher Columbus took sugarcane from Europe to West Indies in 1493, and for many years sugar was an expensive luxury. In Tudor times it was used as a medicine.Gradually sugar plantations were established in many parts of New World.The sugar trade across the Atlantic Became very important.

What is crop rotation ?



Some crops are able to put goodness back in to the soil. Farmers can improve soil by growing different kinds of crops after each other in the same fields. This is known as crop rotation.

Variations on the medieval three – filed system have been used in Europe for over 2000 years. In the three – filed system, fields are divided in to strips which are cultivated by different farmers.

When was Aerial Photography First Used for Map Making ?



The First aerial photographs were taken from a ballon above Paris in 1958.

The photographer and balloonist was Gaspard Felix Tournachon, who was also known as Nadar. These first air photographs of Paris were used to help with mapmaking . Experiments continued with balloons and kites , but it was after World War 1 that aerial Photography became useful.

Where does Cocoa come from ?



Cocoa is made from the beans which develop in the large pod of cacao tree. Cocoa was drunk by the Aztecs of Central America before Europeans arrived.

The Cacao tree is still grown in areas of Central and south America, but most cocoa now comes from West Africa. The tropical cacao tree grows near the Equator.




Where was maize first Grown ?



Maize is grown in many parts of the world which have hot summers. It is a native of Americas, and was an important food crop for many Indians before the Europeans arrived.

For the early European settlers in America, ‘Indian corn’ as it was called, was often a life saver. Most American maize is now used as cattle food, but some is eaten as sweetcorn or turned into cornflakes or flour.


Where Does Rubber comes From?



Natural rubber is made from latex, a milky fluid which is found under the bark of the rubber tree. This tree is a native of the Amazon rain forest and grows in hot , wet equatorial conditions.

The rubber tree was introduced to South-Asia via London’s Botanical gardens at Kew. Plantations is Malaysia and Indonesia have supplied much of the world’s rubber.The bark of the rubber three is cut and latex oozes in to the cup fixed by the rubber tapper. The Latex is then smoked and vulcanized to make rubber.

Where is Tea Grown ?


The tea we drink is made from the crushed leaves of an evergreen bush which grows in hot, damp climates. It seems to thrive at quite high altitude, up to 2300 meters, in tropical areas.

Tea was brought to Europe from China . As the drink became fashionable , plantations of tea bushes were planted by the Dutch in Indonesia and by the British in India and Srilanka. Now tea plantations are also found in Japan, East Africa and on hillsides in Georgia in Asia.

ADD1