Extraterrestrial

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.

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

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.

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

Proxima, a slightly smaller red dwarf than Ross 508, has been frequently observed by astronomers as a giant flare in the past.

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

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

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

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.