The milky way is a huge galaxy with hundreds of billions of stars, and the sun is just one of the less prominent stars that, along with many other stars in the galaxy, orbits the centre of the galaxy.

How exactly did such a complex life emerge on Earth? This is a great mystery to modern humans, but we are almost certain that the "birth of life" is a process that has a very small probability of occurring.

There are many rumors that Pluto is a terrible world, where the temperature is so low that no life can survive, and even if there is life, it may be some extreme virus, so how terrible and unusual is Pluto?

The mass of a star cannot grow indefinitely, it can only reach the "Eddington limit" at most, so beyond this threshold, it will soon "eject" the extra material

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

In the Milky Way, the closest stars to the Sun are 4.22 light years away

Intelligent life is rare in the universe, or perhaps it is just wishful thinking on our part. As mentioned earlier, just in the galaxy, there are hundreds of millions of planets that have the natural conditions to nurture life, so a reasonable speculation is that life has evolved on many planets, and even a number of planets have evolved intelligent life.

Compared to iron, those rare earth elements in the universe, which are heavier than iron, are even rarer

If a shot is fired at the moon from the space station, the bullet fired will be firmly bound by the earth's gravity and it will be impossible to hit the moon

In our universe, whether as large as a galaxy or as small as an electron, we are always in motion, and even when we think we are sitting motionless in our chairs, the earth is carrying us around the sun at a speed of about 30 kilometres per second, and the sun is also in motion, in fact it is carrying the entire solar system around the centre of the milky way, and at a speed of about 220 kilometres per second.