600, Terras

The three comets came closer to the fourth Terrestrial planet. The first comet was at a collision course. A crash would be very destructive. But the iceberg rotation had stopped and hidden behind the comets coma, the geyser started once again at the iceberg’s front. It slowed down the comet. Just before the encounter, the comet suddenly exploded. It broke into a hundred bits that were no longer harmful to the planet.

A shower of ice rocks fell towards the surface. When the first ice hit, it exploded. All the ice rocks were vaporized by the impact. In the craters, there was no ice left. But a big cloud of damp and dirt rose towards the sky.

Soon there were several impacts of various dimensions. Several ice rocks sailed over the surface before they hit. But all the rocks were vaporized. Soon the whole planet was covered by clouds of smoke and damp. Just before the second iceberg reached the planet, it started to rain for the first time. The planet had got an atmosphere.

The second comet exploded in a thousand pieces. They entered into the atmosphere and were dragged in orbit around the planet. The friction of the atmosphere heated the ice rocks so they slowly vaporized in their voyage around the planet. Hundreds of shooting stars flew over the planet and made stripes of damp over the sky.

Then it started to rain again. Just a little in the beginning, but soon much harder this time. The rain dragged particles of dust in the fall. The rain was more like mud than water, and spread all over the surface. Finally the planet had got its soil.

Then the third comet arrived. It exploded in ten bits. They fell towards the planet in a more or less straight direction. The first ice block vaporized merely halfway before it hit the planet. A flood of mud and water was thrown in all directions. Then it all collapsed again. The crater became the first part of the ocean.

The other pieces hit less directly. For a while, there were chaos of explosions, clouds and floods at the planet. But after the last impact, it all seemed to settle. Day by day, the planet formed an ocean, atmosphere and clouds. Nearly the whole planet was covered with water. Only a hundred islands peaked up like mountain tops. Finally, the weather became rather predictable with alternating rain, sunshine and storms.

The star system seemed to have gained its stability, when a comet reached the third Terrestrial planet, half a year later. The two first comets followed the same process as at the fourth planet. They formed oceans and atmosphere. However, the third comet never exploded. It only stroked the planets orbit, ripped of some atmosphere, continued the path. Then it disappeared in the direction to the Kuiper belt.

Half a year later a comet reached the second Terrestrial planet. The process of the fourth planet was repeated. It made seas and atmosphere. However, the planet was hit hard several times. The planet’s core was warm and lava poured out of some cracks in the surface. Volcanoes erupted. The planet’s inner magna mixed with the surface. The smoke poured out and covered the light from the star. An ice-age began.

The first Terrestrial planet was also hit by all three comets. Even though the impacts were not as hard as the second planet, it was much hotter. The short distance to the star warmed a lot, and the gloving core heated just as well. When the surface was penetrated, volcanoes exploded. The core spewed glowing magna and minerals that heated the atmosphere way beyond the boiling point.

In the following years, the four planets stabilized. No traces of the comets were left. The four Terrestrial planets were, in order from the star; a boiling gas planet, a mixed planet with seas, continents and atmosphere, a smaller and rocky planet with a thin atmosphere, and finally a planet basically covered by one single sea.