Extraterrestrial

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?

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

In the photos returned from the rover, we see Mars as a desolate world without a trace of life. Although Mars looks desolate and dry, there are many people who believe that Mars may become a second home for us humans

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

The sun, which we call the 'source of all things', has been sending light and heat to the earth for the past 4.6 billion years, which is why the earth is such a vibrant planet.What exactly does the sun use as fuel and how has it been able to burn for 4.6 billion years without going out?

Although the Earth is just a "grain of dust suspended in the sun" in the universe, for us humans, this "grain of dust" is irreplaceable.

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

Nowadays, Mars is obviously unsuitable for direct human habitation, because the environment of Mars is very different from that of Earth, such as Mars is unusually arid, desolate and without a trace of life. Despite this, scientists are still keen to explore Mars

According to our knowledge of known life, liquid water is essential for life. In other words, if there is liquid water on a planet, there is a possibility of life, and it is for this reason that scientists always consider liquid water as the first requirement when assessing the possibility of life on a planet.

This satellite is the communications satellite LES-1. In the 1960s and 1970s, the United States launched several such communications satellites, from LES-1 to LES-9, which were relatively small, weighing only about 32 kg, each with a horn antenna and an x-band transponder, as well as a 237 MHz signal transmitter, which were powered mainly by solar panels