Extraterrestrial

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.

Because Mercury does not have an atmosphere to play a role in insulation, so the temperature of the back side of Mercury can be as low as minus 172 degrees Celsius, and because of the proximity of the sun, the temperature of the sunny side of Mercury will soar to 432 degrees Celsius under the baking of the sun, so it can be seen that Mercury is simply a realistic version of the "world of ice and fire"

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

After the sun evolves into a red giant, the hydrogen in its core is almost completely fused into helium, so the nuclear fusion inside the sun stops, after which the sun loses its internal radiation pressure and continues to collapse, leading to a constant increase in temperature and pressure in its core, while the helium in the central region of the sun is gradually compressed into the condensed state.

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

Further research shows that this mysterious force accounts for 68.3% of the total mass energy of the universe, and it is because of this that it is able to overcome gravity and become the dominant force controlling the operation of the universe

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

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.

The so-called gravitational equilibrium surface refers to the surface formed by the same point of gravity. On Earth, we call the gravitational equilibrium surface that coincides with the stationary ocean surface the "geodetic level", which is actually equivalent to what we often call sea level.

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