地球如何形成的?

发布网友发布时间：2022-05-15 12:25

共5个回答

热心网友时间：2023-10-23 11:13

大约在45亿年前，一些气体、尘埃、冰粒等物质聚集在一起，逐渐形成了地球的雏形，这个雏形只有一千米的大小，与茫茫宇宙相比，非常小。但就是这个“小地球”不停地旋转，吸收聚集着周围的其他物质，经过上千万年的积累，逐渐形成了现在地球的大小。但是当时的地球和现在的地球完全不一样。

地球刚形成的时候，总是会受到来自宇宙中各种陨石和小行星的撞击，再加上地球内部放射性元素产生了很多热量，以致于当时的地面上到处都是喷发的火山和流动的熔岩，地球基本是一个被熔岩覆盖着的大火球。等到撞向地球的小行星减少了，地球表面的温度降低了，岩浆慢慢固化、结块，形成了坑坑洼洼的原始地壳。

↑原始地壳的形成过程（从左到右：遍地的岩浆-岩浆逐渐冷却-坑坑洼洼的原始地壳）

伴随着岩浆喷出的，是大量的气体和尘埃，由于质量比较轻，这些气体逐渐上升，因为地球引力包裹在地球外层，久而久之形成了原始的大气层。原始大气层中的各种物质混合在一起发生各种化学和物理反应，使得大气层开始降雨。这些雨水在地壳的低洼处流淌，最后顺着地势汇聚到一起，大约在35亿年前，形成了原始海洋。

质量轻的气体上升-原始大气层-降雨

↑原始海洋的形成过程（从左到右）：岩浆喷出

质量重的岩浆、尘埃下沉-原始地壳-积水-原始海洋

后来生命从原始海洋中诞生，经过漫长又复杂的演变，最终活跃在地球的各个角落，才形成了我们现在所生活的地球。

——以上内容参考米莱童书《生命简史》

热心网友时间：2023-10-23 11:14

科学家认为，地球是由气体和尘埃发展而来的——围绕新生恒星旋转的气体和尘埃在重力作用下挤压到一起形成一个炽热的球体，历经数百万年后，这个炽热的球体逐渐冷却，开始出现岩石地壳。地球周围的大气是由有毒气体（包括甲烷、氢、氨等）转化形成的，这些有毒气体由地球表面的火山喷发而来。
历经数十亿年，水分化做雨水从云朵落下，于是地壳的盆地内开始形成海洋，其余的部分便成为陆地。是类地行星。木星、土星、天王星和海王星是类木行星

热心网友时间：2023-10-23 11:14

太阳系在大约50亿年前诞生后，大约过了5亿年，地球开始形成。地球是由原始的太阳星云分馏、坍缩、凝聚而形成的。
首先，星子聚集成行星胎，然后再增生而形成原始地球。

热心网友时间：2023-10-23 11:15

大约46亿年前，由于太阳周围的稀疏质点的相互碰撞，并逐渐向太阳赤道面集中，形成了围绕太阳转的各个行星，其中一颗行星就是地球。

热心网友时间：2023-10-23 11:15

Earth is the only planet known to exist in the universe. With sunrise and sunset, we humans live and multiply on this vital planet. So how did the Earth, which raised us human beings, come into being? Throughout the ages, many people have asked questions and given some answers. With the continuous progress of human society, the causes of the earth from the initial "God" graally closer to science. Many different views have been put forward about the formation of the earth. The modern school believed that the earth was formed in the outer space of the solar system and was captured by the sun as it moved near the sun and became a planet orbiting the sun. Others insist on the results of the Big Bang Theory. According to the Big Bang theory, the universe was formed about 20 billion years ago by the sudden explosion of a relatively small but very large mass of material. In the 19th century, the theory of Earth formation was accepted, a view put forward by the scientist Calvin. He believes that the Earth is formed by the cooling of molten matter. He thinks so, partly because the Earth's temperature is in flux, and partly because it seems to provide evidence that volcanoes spew hot lava out of the house. However, there was ample evidence at the beginning of the 20th century that the Earth had probably never been completely melted. So there's a theory that Earth and the rest of the solar system are formed by the accumulation of st and gas in space. This is probably the result of gravity. This attraction attracts all objects to each other. The discussion and speculation about the origin of the earth can be said to be divided. However, there is so far no answer that we can all be convinced of. Therefore, people need to continue to explore the question of how to raise their own Mother Earth.