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| Sunday, 3 October 2004 |
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Junior Observer |  |
| News Business Features Editorial
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When the lights in the sky go out ...
What are our lights in the sky? The sun, moon and stars of course. Both the sun and the moon can be eclipsed. An eclipse of the Sun is called a solar eclipse while the eclipse of the moon is called a lunar eclipse. An eclipse of the Sun occurs when the Moon passes between Earth and the Sun, blocking off its light. A partial solar eclipse can last several hours but a total eclipse, in which the Sun is completely blotted out, lasts no more than a few seconds. If the Sun was completely blotted out for more than that, you can imagine what life down here would be like for us. Now let's check out how lunar eclipses occur. When the Moon enters the Earth's shadow a lunar eclipse which can last several hours occurs What you may find hard to believe is that at least two solar eclipses and two lunar eclipses takes place each year. However they are not all visible from any one place on Earth.
What are sunspots? Dark patches that mark the surface of the Sun are known as sunspots. These are areas of cooler gas and are caused by strong magnetic fields that temporarily block the outward flow of the heat from inside the Sun. Some sunspots can be upto 100,000 km (62,500 miles) in diameter. That is nearly ten times the width of the Earth. There may be days that the Sun is without any of these Solar blemishes for days, but a typical sunspot can last for a week or two. The number of sunspots varies in a cycle lasting about 11 years. Would you believe that at the peak of the sunspot cycle, more than 100 spots may be visible at a time? Sun's energy The Sun turns 600 million tonnes of hydrogen into helium every second. So, could it run out of energy? Not for thousands of years to come because it is so huge and has enough hydrogen to continue.
Soyuz rocket launch delayed
##### Fact file - The solar system * Despite appearances, the Moon is not silvery. The rocks on the moon reflect only 7 per cent of the light that hits them, so that they are actually dark grey. * Pluto is the only planet whose orbit crosses that of another. Even though Pluto's average distance from the Sun is greater than Neptune's, for part of its orbit Pluto is closer to the Sun than is Neptune. * Saturn has such a low density that it could float on water. * Asteroids are rubble left over from the formation of the solar system. Thousands of them orbit in a belt between the orbits of Mars and Jupitar. * The gas of a comet's tail is far thinner than the Earth's atmosphere. This is the reason that even when Earth passed through the tail of Halley's comet in 1910 there was no noticeable effect on our planet. * Venus is enveloped in unbroken clouds composed of sulphuric acid which is stronger than the acid in a car battery. * All the planets in the Solar system orbit the Sun.
What is an Artificial Satellite? Satellites are objects orbiting (going round and round) a planet. The moon is a natural satellite. Artificial satellites are those put into orbit by man. The first artificial satellite was Sputnik I launched by Russia in 1957. Now there are thousands of satellites orbiting the earth at various heights. Artificial satellites carry instruments that gather and send back information about the earth and its surroundings. This information is of immense value to weather forecasters, scientists, military planners, fishermen and a whole lot of other people.There are various kinds of satellites. The satellites called communications satellites are used to relay telephone messages and radio and television signals. It is such satellites that have made it possible for us to see on TV, live, cricket and tennis matches being played in Europe or Australia. Formerly one had to wait till the next day to see the recorded version. As there is no air in space and therefore no air resistance, satellites do not have to be sleek and streamlined, like rockets. So they come in a variety of shapes depending on the job they have to do. |
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| News | Business | Features
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| Politics | Produced by Lake House |
A Soyuz rocket is due to carry the next Russian-US crew to the
International Space Station (ISS) soon. The launch which was due to take
place on October 9 has been delayed due to technical reasons. Pictured are
(from L) Russian Space Force Officer Yuri Shargin, Russian Cosmonaut,
Salizhan Sharipov and US astronaut Leory Chiao talking to journalists in a
Soyuz-TM space craft simulator prior to their exam in the Star City,
Moscow Region, Russian Federation.
