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.
