Extraterrestrial

An in-depth analysis of the light from these quasars using the Hubble telescope has shown that the Andromeda galaxy's "halo" has two nested gas shells, with the "inner shell" extending outward by about 500,000 light-years and the "outer shell" extending by up to 2 million light-years

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.

At the time of the "family photo" of the solar system, the Voyager 1 probe has reached a distance of 6.4 billion kilometers from Earth, very distant, so in the view of the Voyager 1 probe, the solar system, the major celestial bodies are very small

The moon is the closest planet to the earth and the brightest and most easily observed object in the earth's night sky. Because the moon is always facing the same way towards the earth, for us humans living on earth, we can only ever observe one fixed side of the moon.

Whichever way you look at it, humans cannot be the only intelligent creatures in the universe. As far as we know, the universe has existed for at least tens of billions of years, so a reasonable speculation is that there is probably an advanced civilization in the universe that is hundreds of millions or even billions of years ahead of humans, and if that is the case, their level of technology is something that we humans simply cannot imagine.

Between the Earth and the Moon there exists a much more empty space than imagined, so what can be put down in this space?

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.

Like Earth, Titan has a nitrogen-rich atmosphere, with 98.44% of its atmosphere being nitrogen, making it the only nitrogen-rich planet in the solar system other than Earth.

Below the solar system, there is a star system labeled "alpha Centauri".

So far, we have not found any trace of life on Mars. No one knows whether there is life on Mars. However, when we are exploring Mars, sometimes we will see some interesting scenes, even some garbage. It is strange that there is no one on Mars. Why is there garbage? Where does this rubbish come from?