Xiao Yu did not visit Uranus, because Uranus happened to be on the other side of the sun at this time. However, according to estimates, after another two billion kilometers of flight, Xiao Yu's fleet will collide with Neptune when it reaches the orbit of Neptune.
Pass by and have a rare opportunity to observe Neptune up close.
At this moment, the speed of Xiao Yu's fleet relative to the sun has reached 500 kilometers per second.
During the long journey, Xiao Yu arranged the fleet in the shape of a sphere. At the core of the sphere were three county-level spaceships. Outside, there were seventy township-level spaceships surrounding it. Beyond that, there were a thousand
A village-level spaceship, like stars over the moon, guards the county-level and township-level spacecraft in the center.
Each spacecraft is at least 500 kilometers apart from each other. More than a thousand spaceships form a big ball with a diameter of 10,000 kilometers. Xiao Yu is sitting in the center of the big ball, commanding a huge fleet, majestic in the
Traveling rapidly through space.
In front of the fleet, the village-level spacecraft that was on guard duty emitted laser beams from time to time to vaporize the asteroids blocking the way. Xiao Yu's fleet was like a crab, running rampant in the solar system.
Ahead, the blue ocean-like Neptune has entered Xiao Yu's field of vision. Here, Xiao Yu saw the spectacular large black spot on Neptune and observed Triton at close range.
Triton was once a Kuiper belt object, but was later captured by Neptune's strong gravity, so Triton's orbit is retrograde, and it is slowly approaching Neptune. When its distance from Neptune exceeds the Roche limit, it
It will be torn apart by Neptune's strong gravity, and then the fragments of Triton will hit Neptune.
It is foreseeable that this will be another huge impact event no less than the collision between Jupiter and the Moon. However, because the distance is too far, it will not have much impact on the inner planets.
Xiao Yu did not slow down his fleet. Now that he had made up his mind to leave the solar system, no matter what kind of scenery, Xiao Yu could no longer stop.
The encounter with Neptune lasted only a moment. Not only did Xiao Yu not stop for Neptune, he instead used Neptune's gravity to accelerate the speed of his fleet to 520 kilometers per second.
A month later, Xiao Yu's fleet arrived in the orbit of Pluto. Through the telescope, after expressing some sympathy for Pluto, which was 300 million kilometers away, Xiao Yu continued to fly towards the outer solar system.
This is already the territory of the Kuiper Belt. The Kuiper Belt is the main source of short-periodic comets in the solar system. For example, the famous Halley's Comet is believed to come from here. However, Xiao Yu is not so lucky.
Encounter it. Now Halley's Comet is still wandering in no corner of the solar system.
Here, it is six billion kilometers away from the sun. Looking at the sun from here, it is only slightly brighter than looking at Venus from the earth. She has turned into a point of light and lost all details. But even though it is so far away, she
It still dominates everything here. Yes, in the Kuiper Belt, celestial bodies such as Pluto, Xena, and Sedna are still orbiting the bright spot in the distance together with countless cold stones.
Here, it is cold and dark. Loneliness is the eternal melody of the universe, and light is the rare scenery in the universe.
There are at least 100 million celestial bodies scattered in this huge space. But Xiao Yu can't see anything. Compared with this huge space, the density of matter is too thin.
Xiao Yu is still moving forward. In space, because he has lost the reference object, he is not aware that he is moving. Xiao Yu's huge fleet just floats quietly in space without any movement.
Xiao Yu has been observing the intensity of the solar wind. During this nine-month long journey, Xiao Yu saw that the speed of the solar wind was slowly decreasing, which meant that the influence of the sun on this place was getting weaker and weaker.
Gradually, gradually, the speed of the solar wind dropped from several hundred kilometers per second to below the speed of sound, which is 340 meters per second. Xiao Yu knew that he had arrived at the edge of the solar system.
Outside, there will be an infinite world of interstellar media. The sun, with its powerful energy and solar wind, has carved out a world of its own in the interstellar medium, and the place where Xiao Yu is located will be the Sun Empire and the interstellar world.
The border of the medium.
Here is the heliopause. Here, it is 18 billion kilometers away from the sun.
Under the influence of the interstellar medium, the speed of the solar wind finally dropped below the speed of sound. The solar wind will have a fierce confrontation with the interstellar medium here, and countless particles will collide fiercely where Xiao Yu cannot see.
Temperatures as high as several thousand degrees Celsius.
Yes, it is cold and dark here, and humans will be instantly frozen into ice blocks here, but the temperature here is indeed as high as several thousand degrees Celsius.
Temperature is just a physical quantity that measures the intensity of thermal motion of the molecules of an object. The material here is too little and too thin, so although the temperature is high, it has no effect on Xiao Yu. Just like the ionosphere of the earth,
The temperature is as high as over a thousand degrees, but there are still many artificial celestial bodies flying freely there.
This is the final battlefield. In the confrontation with the interstellar medium, the solar wind was completely defeated. Xiao Yu knew that after passing through this place, except for gravity, the sun would have no other means to exert influence here.
Xiao Yu spent two days passing through here and through the heliosphere. Looking at the detector, the number of high-energy charged particles from the sun slowly decreased and finally disappeared. Looking at the distant star, it was already a little dim.
, a bright spot that is not much different from other stars in the universe, there is an unspeakable feeling in Xiao Yu's heart.
"Mother, dear mother, goodbye, goodbye." Xiao Yu murmured to himself, feeling the urge to cry.
Moving forward, we will reach the interstellar medium, which is the world of hydrogen and helium from the Milky Way. The matter here is so thin that it is unimaginable, not even reaching the level of one atom per cubic centimeter. Such a density is equivalent to
A drop of water has a material density evenly distributed in a space of five million cubic kilometers.
What will greet Xiao Yu ahead will be a lonely journey of more than six thousand years in such a space.
After leaving the heliosphere, Xiao Yu has been depressed for a year. During this year, Xiao Yu has been in a state of mental trance. The daily operations of the fleet have been handed over to automatic programs.
, Xiao Yu just looked at the direction of the sun through the telescope every day, immersed in memories and couldn't extricate himself. Fortunately, the route had already been set, and there was no need to worry about being attacked by asteroids here, so Xiao Yu's fleet did not have any accidents.
Condition.
Here, there are already 35 billion kilometers away from the sun. It takes thirty-two hours for the sun's light to reach here. But here, in such a remote place, Xiao Yu actually has
made a major discovery.
He discovered a planet.
Yes, it has reached hydrostatic equilibrium and has enough mass to clear out other small celestial bodies in its orbit. This planet, no matter how you look at it, meets astronomers' definition of a planet.
Its mass is 1.5 times that of the Earth. It is a rocky planet that orbits the sun at an extremely slow speed, with a period of 732 years.
Looking at this planet, Xiao Yu's heart suddenly became enlightened and he understood many things.
Before, humans have been wondering whether there is another large planet beyond the orbit of Pluto. Otherwise, there is no way to explain the weird orbits of many small celestial bodies in the Kuiper Belt. Now, Xiao Yu finally found the answer.
There is indeed a large planet here. But because it is too small and too dark here, humans have not been able to discover it.
Xiao Yu named this planet "Lost Star". This is a lost place, and there has never been a trace of it in human written records.
Xiao Yu poured great energy into the Lost Star. Xiao Yu even rushed to build a detection satellite and launched it in the orbit of the Lost Star. In this way, even if Xiao Yu's fleet continues to leave, Xiao Yu
Yu can also continue to observe the lost stars.
The Lost Star has no atmosphere, but on the surface of the Lost Star, Xiao Yu observed a liquid that looked like liquid nitrogen and a white solid that looked like water ice. This shows that if there is a suitable temperature for the water ice to melt and the liquid nitrogen to sublimate,
It could also have an atmosphere like Earth.
There are mountains on the Lost Star, which proves that it once had crustal movement, which proves that it has a liquid, hot core. Perhaps there will also be volcanic eruptions and hot springs caused by geothermal heat, and in the hot springs
Wherever there is, life may exist.
Xiao Yu has a lot of thoughts in his heart.
Xiao Yu's observation of the Lost Star lasted for a full year. Until he could no longer receive signals from the satellite, Xiao Yu had to give up his research on it with regret.
The discovery of the Lost Star saved Xiao Yu from his depression. Xiao Yu regained his spirit and gained the desire to explore.
The compilation work of the Heroes of the Sky has been restarted, and research on projects such as ultra-distance communication, anti-gravity technology, and new-generation spacecraft engines has also been put on the agenda. Physical theoretical research is also being carried out in full swing, and even huge scientific research*
* Calculating calculations have already scheduled the calculation schedule of the main computer to three hundred years in the future.
In other words, the data that needs to be calculated now is enough for the main computer to operate at full load for three hundred years. This result made Xiao Yu smile bitterly. However, there was plenty of time in the journey, and Xiao Yu was not in a hurry.
Time slowly slipped away in this lonely but fulfilling state. Since the encounter with the Lost Star, Xiao Yu has not encountered any material objects again. This situation has lasted for six hundred years.
Six hundred years later, Xiao Yu arrived at a place.
Here is the Oort cloud, which is one light-year away from the sun.