如果太阳系中有未知行星撞地球的话，我们早就可以观察到。的翻译：If the unknown planet hit the Earth in the solar system, we could have been observed. 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

If the solar system in the unknown planet hit the Earth, then we would have to be observed.

If the unknown planet hit the Earth in the solar system, we could have been observed.

If in solar system has the unknown planet to hit Earth's, we already may observe.

If there is an unknown planet in the Solar System crashed into the earth, we can be observed.

If the unknown planet hit the Earth in the solar system, we could have been observed.