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博客园 - Jason_Asm

搬家了 怎样做研究--一篇绝对有价值的文章 理发用语中英文对照 英国打工经验谈 GHOST的黑色灾难!! Miss You~ GF明天去SWEDEN... GMAIL 一场失败的比赛。 The first exam will be on Sep 29th. 被PROLOG占据一天 人工智能历史 Begin to EnD VISA ~~~ Scarborough Fair 《斯卡布罗集市》 新概念英语4册第36课(*) Recently Working 辞职申请书 1G Free Space
新概念英语4册第35课(*)
Jason_Asm · 2004-09-01 · via 博客园 - Jason_Asm

Space odyssey

The Moon is likely to become the industrial hub of the Solar System, supplying the rocket fuels for its ships, easily obtainable from the lunar rocks in the form of liquid oxygen. The reason lies in its gravity. Because the Moon has only an eightieth of the Earth`s mass, it requires 97 percent less energy to travel the quarter of a million miles from the Moon to Earth-orbit than the 200 mile-journey form Earth`s surface into orbit!

This may sound fantastic, but it is easily calculated. To escape from the Earth in a rocket, one must travel at seven miles per second. The comparable speed from the Moon is only 1.5 miles per second. Because the grabity on the Moon`s surface is only a sixth of Earth`s (remember how easily the Apollo astronauts bounded along), it takes much less energy to accelerate to that 1.5 miles per second than it does on Earth. Moon-dwellers will be able to fily in space at only three percent of the cost of similar journeys by their terrestrial cousins.

Arthur C.Clark once suggested a revolutionary idea passes through three phases:

1. ' It`s impossible -- don`t waste my time. '

2. ' it`s possible, but not worth doing. '

3. ' I said it was a good idea all along. '

The idea of colonizing Mars -- a world 160 times more distant than the Moon -- will move decisively from the second phase to the third, when a significant number of people are living permanently in space. Mars has an extraordinary fascination for would -- by voyagers. America, Russia and Europe are filled with enthusiasts -- many of them serious and senior scientists --  who dream of sending people to it. Their aim is understandable. It is the one world in the Solar System that is most like the Earth. It is a world of red sandy deserts ( hence its name -- the Red Planet), cloudless skies, savage sandstorms, chasms wider than the Grand Canyon and at least one mountain more than twice as well as Everest. It seems ideal for settlement.


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Everest  珠穆朗玛峰