"earth"

Prehistoric civilization have always been the talk of the town, and it's no wonder - after all, humans have been around for so short a time in the history of the planet that if we were to compress the history of the planet into a single day, then humans would probably only appear in the last two minutes of that day. In the past, there have been frequent claims of the discovery of suspected prehistoric civilization, the most notable of which would be a two-billion-year-old nuclear reactor.

Do UFOs exist?

If we dig up all the sand in the Sahara Desert, then we can see the "bedrock" of this desert

In our solar system, there are 2 planets in the habitable zone of the solar system, one of which is our home planet Earth, and the other is Mars

A rigorous discussion of the unknown is not possible, so it is necessary to narrow down the universe we are discussing to only the universe we can see

The earth was born more than 4 billion years ago, when it was very different from the earth of today, one of which is that the environment of cosmic space is more different.

Since there are many lakes in China, many of them have the title of "largest".

The energy released by the sun's nuclear fusion reaction, in addition to making the sun shine and heat, there is an important role, that is, to resist its own gravity

For humans, the universe is too dimensional for us to see the details of its depths for the time being

It has been billions of years since life appeared on earth, and although there are seven planets in our solar system in addition to earth, as well as a number of dwarf planets, moons and other relatively large bodies, so far we have not found alien life on any other planet in our solar system for the time being. Even mars, another earth-like planet in the habitable zone of our solar system, has not found a single sign of life. Could it be that life on earth is really unique and no other planet is allowed to have life?