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The Giant Planets

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THE GIANT PLANETS :

 

 

 

 

 


 

 

 

 

 

 

 

 

 

1. WHAT ARE SATURN’S RINGS?
Ans: Saturn’s rings are the planets shining halo, first seen by Galileo Galilei ( I564-1642), who invented the first simple telescope in 1609. The rings are made of countless billions of tiny chips of ice and dust, few bigger than a refrigerator and most the size of ice cubes. The rings are incredibly thin no more than 50 m deep yet they stretch from 7,000 km to 74,000 km out into space. One of Saturn’s rings is as thin as a piece of tissue paper being stretched over a football pitch.

 


2. HOW WINDY IS SATURN?
Ans: Saturn’s winds are even faster th roar round up to I,800 km/h. But Neptune’s a even faster!Jupiter’s and the planet.

 


3. WHAT IS THE CASSINI DIVISION?

Ans: Saturn’s rings occur in broad bands referred to by the letters A to G. In 167 the astronomer Cassini spotted a dart gap between rings A and B. This is now called the Cassini division, after him.

 


4. HOW MANY MOONS HAS SATURN?

Ans: Saturn has at least 18 moons, including Lapetus, which is dark on one side and light on the other.

 


5. HOW BIG IS JUPITER?
Ans: Very big. Even though Jupiter is largely gas, it weighs 320 times as much as the Earth and is 142,984 km in diameter.

 


6. HOW LONG DOES IT TAKE JUPITER TO ORBIT THE SUN?
Ans: Jupiter takes 11 years and 314 days (by our Earth calendar) to complete its journey around the Sun.

 


7. WHAT ARE THE GIANT PLANETS?
Ans: Jupiter and Saturn, the fifth and sixth planets out from the Sun, are the giants of the solar system. Jupiter is twice as heavy as all the planets put together. Saturn is almost as big. Unlike the inner planets, they are both made largely of gas, and only their very core is rocky. This does not mean they are vast cloud balls. The enormous pressure of gravity means the gas is squeezed until it becomes liquid, and even solid.

 


8. COULD YOU LAND ON JUPITER?
Ans: No. Even if your spaceship could withstand the enormous pressures, there is no surface to land on – the atmosphere merges unnoticeably into deep oceans of liquid hydrogen.

 


9. HOW FAST DOES JUPITER SPIN?
Ans: Jupiter spins faster than any other planet. Despite its huge size, it turns right around in just 9 hours 55 minutes, which means the surface is moving at 45,000 km/h!

 

 

The Inner Planets

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THE INNER PLANETS :

 

 

 

 

 

 

 

 

 

1. WHAT ARE THE INNER PLANETS?
Ans: The inner planets are the four planets in the solar system that are nearest to the Sun. These planets- Mercury, Venus, Earth and Mars are small planets made of rock, unlike the bigger planets further out, which are made mostly of gas. Because they are made of rock, they have a hard surface a spaceship could land on, which is why they are sometimes called terrestrial(earth) planets. They all have a thin atmosphere, but each is very different.

 

2. WHY IS MARS RED?
Ans: Mars is red because it is rusty.The surface contains a high proportion of iron dust, and this has been oxidized in the carbon dioxide atmosphere.

 

3. WHAT’S FRIGHTENING ABOUT MARS’S MOONS?
Ans: One night American astronomer Asaph Hall got fed up with studying Mars and decided to go to bed.But his domineering wife bullied him into staying up and that night he discovered Mars’s two moons.Mocking his fear of his wife,he named the moons Phobos (fear) and Deimos (panic), after the attendants of the Roman war god, Mars.

 

4. LIFE ON MARS?
Ans: The Viking landers of the 1970 s found no trace of life. Then, in 1996, microscopic fossils of what might be mini-viruses were found in a rock from Mars.These turned out not to be signs of life after all.

 

5. WHY IS VENUS CALLED THE EVENING STAR?
Ans: Venus reflects sunlight so well it shines like a star. But because it is quite close to the Sun, we can see it in the evening, just after the Sun sets.We can also see it just before sunrise.

 

6. WHAT ARE THE INNER PLANETS MADE OF?
Ans: Each of the inner planets is formed a little bit like an egg with a hard “shell” or crust of rock, a “white” or mantle of soft, semi-molten rock, and a”yolk” or core of hot, often molten, iron and nickel.

 

7. WHAT CANYON IS BIGGER THAN THE GRAND CANYON?
Ans: A canyon on Mars! The surface of Mars is more stable than Earth’s, and there is no rain or running water to wear down the landscape. It has a volcano called Olympus Mons which is 17 miles (27 km s)high three times higher than Mount Everest. It also has a great chasm, discovered by the Mariner 9 space probe and called the Valles Marineris. This is
over 4,000 km long and four times as deep as America’s Grand Canyon.

 

8. COULD YOU BREATHE ON MERCURY?
Ans: Not without your own oxygen supply. Mercury has almost no atmosphere-just a few wisps of sodium because gases are burned off by the nearby Sun.

 

9. WHAT IS THE AIR ON VENUS?
Ans: Venus’s atmosphere would be deadly for humans. It is very deep, so the pressure on the ground is huge. It is made mainly of poisonous carbon dioxide and is also filled with clouds of sulphuric acid.

 

10. HOW HOT IS MERCURY?
Ans: Temperatures on Mercury veer from one extreme to the other because it has too thin an atmosphere to insulate it. In the day, temperatures soar to 400° C; at night they plunge to -175°C.

 

 

THE SUN

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THE SUN :

 

 

 

 

 

 

 

 

 

 

 

 

 

1. WHAT IS THE SUN?
Ans: The Sun is an average star, just like countless others in the universe. It formed from gas left behind after an earlier, much larger star blew up and now, in middle-age, burns yellow and fairly steadily – giving the Earth daylight and remarkably constant temperatures. Besides heat and light, the Sun sends out deadly gamma rays, X-rays and ultraviolet, as well as infrared and radio waves. Fortunately we are shielded from these by Earth’s magnetic field and atmosphere.

 

 

2. WHAT IS A SOLAR ECLIPSE?

Ans: A solar eclipse is when the Moon moves in between the Sun and the Earth, creating a shadow a few hundred kilometres wide on the Earth.

 

 

3. WHAT MAKES THE SUN BURN?

Ans: The Sun gets its heat from nuclear fusion.Huge pressures deep inside the Sun force the nuclei (cores) of hydrogen atoms to fuse together to make helium atoms, releasing huge amounts of nuclear energy.

 

 

4. WHAT IS THE SUN’S CROWN?

Ans: The Sun’s crown is its corona, its glowing white hot atmosphere seen only as a halo when the rest of the Sun’s disc is blotted out by the Moon in a solar eclipse.

 


5. HOW HOT IS THE SUN?
Ans: The surface of the Sun is a phenomenal 5500″C, and would melt absolutely anything. But its core is thousands of times hotter at over 15 million C.

 


6. WHAT IS THE SOLAR WIND?
Ans: The solar wind is the stream of radioactive particles constantly blowing out from the Sun at hundreds of kilometres per second. The Earth is protected from the solar wind by its magnetic field, but at the Poles the solar wind interacts with Earth’s atmosphere to create the aurora borealis or northern lights.

 


7. HOW OLD IS THE SUN?
Ans: The Sun is a middle-aged star. It probably formed about 4.6 billion years ago. It will probably burn for another five billion years and then die in a blaze so bright that the Earth will be scorched right out of existence.

 


8. WHAT ARE SUNSPOTS?
Ans: Sunspots are dark blotches seen on the Sun’s surface. They are thousands of kilometres across, and usually occur in pairs. They are dark because they are slightly less hot than the rest of the surface. As the Sun rotates, they slowly cross its face – in about 37 days at the equator and 26 days at the Poles. The average number of spots seems to reach a maximum every I| years, and many scientists believe these sunspot maximums are linked to periods of stormier weather on Earth.

 


9. WHAT ARE SOLAR FLARES?
Ans: Flares are eruptions from the Sun’s surface that fountain into space with the energy of one million atom bombs for about five minutes. They are similar to solar prominences, the giant flame-like tongues of hot hydrogen that loop 32,000 km into space.

 


10. HOW BIG IS THE SUN?
Ans: The Sun is a small-to-medium-sized star 1,392,000 km in diameter. It weighs just under 2,000 trillion trillion tonnes.

 

 

The Earth

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THE EARTH 

 

 

 

 

 

 

 

 

 

 

1.HOW DID THE EARTH BEGIN ?
Ans: Around 4.6 billion years ago, neither the Earth nor any of the other planets existed. There was just this vast, dark, very hot cloud of gas and dust swirling around the newly formed Sun. Gradually,the cloud cooled and the gas began to condense into billions of droplets. Slowly these droplets were pulled together into clumps by their own gravity and they carried on clumping until all the planets, including the Earth, were formed.But it took another half a billion years before the Earth had cooled enough to form a solid crust with an atmosphere around it.

 

 

 2.HOW BIG IS THE EARTH ?
Ans: Satellite measurements show it is 40,075 km around the equator and 12,757 km across. The diameter between the poles is slightly less by 43 km.

 

 

 3.HOW OLD IS THE EARTH?
Ans: The Earth is about 4.6 billion years old. The oldest rock is about 3.8 billion years old. Scientists have also dated meteorites that have fallen from space, and must have formed at the same time as the Earth.

 

 

4.WHAT SHAPE IS THE EARTH?
Ans: The Earth is not quite a perfect sphere. Because it spins faster at the equator than at the Poles,Earth bulges at the equator. Scientists describe Earth’s shape as “geoid”,which simply means Earth-shaped!

 

 

5.WHAT’S SO SPECIAL ABOUT THE EARTH?
Ans: The Earth is the only planet with temperatures at which liquid can exist on the surface and is the only planet with an atmosphere containing oxygen. Water and oxygen are both needed for life.

 

 

6.WHY DOES THE EARTH SPIN?
Ans: Earth spins because there is nothing to stop it spinning. The Sun’s gravity keeps it in orbit.

 

 

7.EXACTLY HOW LONG IS A YEAR?
Ans: Every year the Earth travels once around the Sun. This epic journey covers a distance of 938,886,400 km and takes exactly 365.24 days,which gives us our calendar year of 365 days. To make up the extra 0.24 days, we add an extra day to our calendar at the end of February in every fourth year which is called the leap year and then we have to knock off a leap year every four centuries.

 

 

8. HOW LONG IS A DAY?
Ans: A day is the time Earth takes to turn once. The stars move to the same place in the sky every 23 hours, 56 minutes and 4.09 seconds (the sidereal day). Our day (the solar day)is 24 hours, because Earth is moving around the Sun, and must turn an extra for the Sun to be in the same place in the sky.

 

 

9. WHO WAS COPERNICUS?
Ans: In the 1500 s, most people thought the Earth was fixed in the centre of the universe, with the Sun and the stars revolving around it. Nicolaus Copernicus(1473-1543) was the Polish astronomer who first suggested the Earth was moving around the Sun.

 

 

 

 

 

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THE MOON

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THE MOON 











 

 

 

1. WHAT ARE THE MOON SEAS?

Ans: The large, dark patches visible on the Moon’s surface are called seas, but in fact they are not seas at all. They are huge plains formed by lava flowing from inside the Moon.

2.WHO WERE THE FIRST MEN ON THE MOON?

Ans: The first men on the Moon were Neil Armstrong and Buzz Aldrin of the US Apollo II mission. They landed on the Moon on July 20,1969.As Armstrong set foot on the Moon, he said: “That’s one small step for (a) man, one
giant leap for mankind.”

3. WHAT IS MOONLIGHT?

Ans: The Moon is by far the brightest thing in the night sky.But it has no light of its own.Moonlight is simply the Sun’s
light reflected off the white dust on the Moon’s surface.

4. WHAT IS A LUNAR ECLIPSE?

Ans: As the Moon goes around the Earth,sometimes it passes right into Earth’s shadow, where sunlight is blocked off. This is a lunar eclipse. If you look at the Moon during this time, you can see the dark disc of the Earth’s shadow creeping across the Moon.

5. WHAT IS THE MOON?

Ans: The Moon is the Earth’s natural satellite. It has circled around the Earth for at least four billion years. It is a rocky ball about a quarter of Earth’s size and is held in its orbit by mutual gravitational attraction. Most scientists believe that the Moon formed when, early in Earth’s history, a planet smashed into it. The impact was so tremendous that nothing was left of the planet but a few hot splashes thrown back up into space.Within a day of the smash, these splashes had been drawn together by gravity to form the Moon.

6. WHAT IS A HARVEST MOON?

Ans: The harvest moon is the full moon nearest the autumnal equinox (when night and day are of equal length). This moon hangs bright above the eastern horizon for several evenings,providing a good light for harvesters.

7. WHY DOES THE MOON LOOK LIKE CHEESE?

Ans: The moon looks like Swiss cheese because it is full of holes and can appear yellowish. The holes are craters in the surface created when it was bombarded by huge rocks early on in its history.

8. WHAT IS A NEW MOON?

Ans: The Moon appears to change shape during the month because, as it circles the Earth, we see its bright, sunny side from a different angle. At the new moon, the Moon lies between the Earth and the Sun, and we catch only a crescent – shaped glimpse of its bright side. Over the first two weeks of the month, we see more and more of the bright side (waxing) until full moon,When we see all its sunny side. Cover the next two weeks, we see less and less(waning), until we get back to just a sliver-the old moon.

9. WHY DOES THE SEA HAVE TIDES?

Ans: The Moon’s gravity draws the oceans into an oval around the Earth, creating a bulge of water on each side of the world. These bulges stay beneath the Moon as the Earth spins round and so seem to run around the world making the tide rise and fall as they pass.

10. HOW LONG IS A MONTH?

Ans: It takes the Moon 27.3 days to circle the Earth, but 29.53 days from one full moon to the next, because the Earth moves as well. A lunar month is the 29.53 days cycle. Calendar months are entirely artificial.

 

 

 

 

 

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