Extraterrestrial

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

It's good news that Earth has regained contact with Voyager 2 after such a long period of loss of control. But somewhat sadly, Voyager 2 is carrying very little battery power left

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?

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.

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

Compared to radio messages sent by humans, this method seems to be more suitable for intelligent civilizations to announce their presence in the universe, because this method belongs to the "broadcast" in space, and intelligent civilizations in all directions can be observed

Titan is the largest moon of Saturn and the second largest in our solar system, even a little larger than Mercury, one of the eight planets. Due to tidal locking, Titan's rotation period and revolution period are the same, similar to our Moon

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

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.

The Big Dipper is located in the constellation Ursa Major, and under good observing conditions, we can find them almost every day in the night sky of the Northern Hemisphere. These seven shining stars form a unique spoon shape that is very easy to recognize.