The reasons for leaving are varied, and the intel does not document them in detail, except for a few typical galaxies.

Ye Han was particularly interested in this aspect of the situation, so he looked at it very carefully.

The first stop after the aliens leave their home galaxy is a long-lived red dwarf, which is the closest star to the alien's home star, and the relationship between the two is equivalent to that of the Sun and Proxima Centauri.

The aliens found that there were several planets there, and they planned to settle there, but they flew to the earth and found that the red dwarf star was too barren, and both stars and planets there were light elements, and only a small amount of iron could be found in the core of the planet, and there were incredibly few elements above the iron, much lower than the gold reserves on the earth.

This is simply an unbearable nightmare for an alien civilization that is desperately lacking in heavy elements, so the aliens do not hesitate to rush to the next goal.

Seeing this, Ye Han couldn't help grinning, he was no longer the big-headed soldier who didn't know anything about astronomy, he knew very well that Proxima Centauri was a red dwarf, and in many science fiction works, there were really a lot of themes about immigrating Proxima Centauri, he really wanted to ask those authors now, do you know what happened to Proxima Centauri?

The information did not mention the details of the second and third targets, and they were abandoned by the aliens anyway.

The fourth target is a nice place, a yellow dwarf star similar to the Sun, with five planets, one of which is located in the habitable zone!

According to the technological level of aliens, it is not difficult to transform this planet into an ecological planet and settle down, but the bad is in the galaxy environment, the Kuiper belt in the outer layer of the galaxy is wide and thick, at least hundreds of comets are always orbiting in the galaxy, and each planet is scarred by comets.

You don't have to ask to know that this is a young galaxy that has just formed.

Aliens are not afraid of the galaxy being young, but those five planets are all terrestrial planets, so they can't bear it, even if there is a giant planet outside, they can block a comet, right?

In the end, the aliens had no choice but to abandon this young and dangerous galaxy.

Next is the seventh target, which is also a galaxy that looks very suitable at first glance, but after entering the galaxy, it is found that the planet in the habitable zone rotates too slowly, and the magnetic field is almost none, and no one can save the planet unless the alien shell can resist the high-energy rays of interstellar space.

Another time, the conditions of the galaxy were very good in all aspects, except that the habitable zone was not a single planet, but a pair of twin stars orbiting each other!

The situation is also good for the binary stars, both of which are potential ecological stars with liquid water, and the strength of the magnetic field and gravity are good, which can be said to be the best choice for aliens to encounter after leaving the home galaxy.

But the distance between the two planets is less than 200,000 kilometers, and the gravitational pull of the two planets is entangled with each other, and every high tide is as exaggerated as a tsunami, and when you overhead another planet, the gravitational pull under your feet is significantly reduced, and vice versa, your weight will also increase.

And that's not all, it's not just the tides that follow gravity, it's the earth and the liquid core!

The gravitational pull of the two planets tears each other's earth apart, and the most direct result is that the two planets are densely populated with volcanoes, and countless active volcanoes will erupt on time when they turn to the opposite side, and then gradually stop after turning out of the opposite side, just like two spherical giant starships spraying each other with cannons.

If that's the case, the aliens can overcome it, but the more troublesome part is that the two planets are so close that one day, the two of them will tide lock on each other, like the moon, and face each other forever.

At that time, the two planets will turn into yellowish eggs together, and no one knows exactly what the result will be.

The aliens had no choice but to abandon the system, but the starship stayed there for decades, fetching a lot of resources from the planet there before reluctantly leaving.

Without those resources, Starship might not have been able to make it to the solar system.

Aliens have also encountered some strange situations.

For example, there is a huge giant planet next to the star, because of the gravitational influence of the giant planet, this star is very active, and the solar wind is raging in flares, if such a galaxy can also evolve an ecosystem, it must be exactly like the legendary hell.

There is also a giant planet in the habitable zone, and that giant planet has a moon with great potential for transformation, but the aliens have encountered an old problem, the heavy element content of this galaxy is too low, and it is not impossible to settle there, but the scarce heavy elements cannot last for several generations.

It's better to leave late than early, and the aliens are gone again.

Later, the aliens seemed to have mastered certain rules, and they no longer chose targets casually, but would rather go farther at a time and choose the right target.

And these targets have something less than accurate in common, and they must be single-star, binary, or clustered to the exclusion of all stars; It must be a yellow dwarf, too small or too big is not acceptable; The number of planets must not be too small, and there must be a giant planet shield in the middle of the galaxy; The age of galaxies cannot be too low, otherwise the celestial system is unstable; The most important point is that the content of heavy elements must meet the standard!

Ye Han didn't know how long the aliens had been looking for this standard, but they finally found the solar system and the earth, and from all aspects, the earth was very much in line with the aliens' new home standard.

Thinking of this, Ye Han was puzzled, could it be that the aliens' home planet is the same as the earth's environment? This isn't necessarily too coincidental, is it? Or is it that only in an environment similar to that of the earth can higher intelligent beings evolve?

If this is the case, when humans leave the solar system and migrate to the stars, they don't have to find a suitable galaxy by themselves, as long as they refer to the criteria set by the aliens to find a target, the success rate can be greatly improved.

For a moment, Ye Han suddenly had a feeling of being tall...... There must be a coincidence in the birth of life, but there must also be an inevitable aspect, so are intelligent beings like humans and aliens a coincidence or an inevitability? Or is intelligent beings a prank on the universe?

couldn't think of a reason, Ye Han simply reported this information to the Northern Capital, anyway, the Northern Capital is an expert, this kind of thing still gives them a headache.

Well...... Presumably, after defeating the aliens, humanity is not far from interstellar immigration.

As soon as he sent the information away, Ye Han suddenly received a communication request, and he immediately turned on the radio: "I'm Ye Han!" After speaking, he realized that the communication signal came from hundreds of kilometers away.

At this time, he heard a voice: "Captain, I'm Luo Qi, we're back!" ”

Ye Han jumped up suddenly: "Luo Qi? Are you back? How's it going? ”

Luo Qi sighed: "Let's go back and talk about it." ”

Ye Han's heart instantly sank to the bottom.