Extraterrestrial

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

The "Ryder" crater is actually located on the rim of a much larger crater. Exploration data show that this old crater is about 70 km in diameter, and its rim rises high above the inner area, with an altitude difference of about 3 km

The moon has no people and no other living creatures, but scientists have found a lot of garbage on the surface of the moon, which is very strange, since the moon has no people, why would there be so much garbage?

The solar system is located in a region with a stellar density of only 72 million parts per million of the highest stellar density region in the Milky Way, which is a remote and inhospitable part of the galaxy.

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.

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

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 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.

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

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