Chapter 99 98: Jupiter
Li Qingsong knew that Bright Nebulae were further divided into Emission Nebulae and Reflection Nebulae, depending on how they produced light.
Emission Nebulae were those that could emit their own light. Typically, the molecules of interstellar dust that constituted them were ionized by massive celestial bodies, causing them to release light in various colors.
Take the Aquila Nebula, for example. Within this nebula lay an extremely famous structure: the Pillars of Creation.
Several enormous pillars, stretching for tens of light-years, extended from this nebula. The gas clouds forming these pillars collapsed inward under the influence of external disturbances and their own Gravity, eventually condensing into stars.
Dozens, even hundreds, of massive stars were being nurtured in this stellar nursery. It was precisely the birth of these stars that ionized and heated the dust composing the nebula, causing it to release light.
Reflection Nebulae, on the other hand, did not emit light themselves but could reflect the light of nearby stars. The Witch's Head Nebula in Orion, for instance, glowed because it reflected the light of Rigel.
In addition, there was a more unique type: the Planetary Nebula.
When a massive star reached the end of its evolution and underwent a Supernova Explosion, its constituent materials would be violently cast into interstellar space. At its core, a dense celestial body would be left behind—either a neutron star or a Black Hole.
In the case of a neutron star, its extremely high radiation, energy, and magnetic field would "stir up" the entire nebula, granting it the ability to emit light as well.
The most famous of these was the Crab Nebula.
This massive star was located about 6,500 light-years from Earth. It had exploded around the time of the Song Dynasty back on Earth.
Despite the immense distance, the light from its explosion was so intense that it was visible even during the daytime on Earth and was clearly recorded by the people of that era.
However, none of these three modes of nebular luminescence seemed to fit the current situation.
'Regarding the nebula I'm observing now... first, I can rule out the possibility that it suddenly moved here from somewhere else.'
'Its velocity couldn't possibly be that high.'
'If it didn't travel here from another location, then it must have been here all along. And if it was always here, yet I never observed it before, it must have previously been a dark nebula.'
'There are only three reasons a dark nebula would become a Bright Nebula: one, it's ionized by its own nascent stars; two, it's reflecting the light of a nearby star; or three, it contains a dense celestial body at its core.'
'But none of those three scenarios are possible here.'
Combining this with the intelligence he had previously obtained from the Blutuk captives, a single possibility surfaced in Li Qingsong's mind.
The Blutuk migration fleet had arrived.
They were traveling from the distant Gliese 625 Star System toward the Solar System. Halfway through their journey, the fleet must have entered this dark nebula.
The high-speed ions ejected from their ships' engines, much like a dense celestial body or a nascent star, had "stirred up" the entire nebula, imbuing it with greater energy. As a result, this once-dark nebula, incapable of emitting its own light, had begun to glow, allowing him to observe it.
Li Qingsong had long known that the Blutuk Civilization's fleet would arrive sooner or later. There was nothing strange or shocking about that.
The only thing that was truly staggering was that the high-speed plasma ejected from a single ship's engine was minuscule in terms of energy compared to an entire nebula.
This particular nebula wasn't very large—only about ten billion kilometers across, roughly enough to envelop the entire Solar System.
Compared to the vast nebulae that spanned tens or even hundreds of light-years, it was undoubtedly just a tiny speck.
But that was only in comparison to other nebulae.
To intelligent life, it was still unimaginably vast.
'A single ship could only "light up" a tiny fraction of the nebula. To illuminate the entire thing... just how large must that fleet be?'
Even now, using the most technologically advanced, largest-aperture telescope he could build, the nebula was still just a dim, unremarkable point of light in Li Qingsong's eyes. It seemed to hold nothing worthy of note.
But as he gazed at that dim point of light, Li Qingsong seemed to see an endless fleet of colossal ships. He saw countless Space-Air Carriers, rows of heavy transport vessels, and squadron after squadron of powerful Warships possessing world-shattering might...
'The energy exhaust from a single ship is limited. But countless ships, combined, could light up an entire nebula.'
'What an immense scale. A migration spanning over twenty light-years, from the Gliese 625 Star System all the way to the Solar System... what a magnificent spectacle.'
'Compared to that...'
Li Qingsong glanced at his own migration fleet.
The scale of his own fleet was already quite massive. But compared to the Blutuk migration, it was like an ant dragging a breadcrumb next to a heavy freight train.
Li Qingsong felt a profound sense of his own insignificance. And with that sense of smallness came immense pressure.
Just that single glance was enough. The surging pressure was so intense it nearly suffocated him.
'I only have a little over two hundred years. In just two hundred years, I'll have to face an enemy this powerful?'
'Can I really, truly defeat them?'
Li Qingsong closed his eyes. A long moment passed before he opened them again. All traces of confusion, fear, and anxiety had vanished from his gaze, replaced by only calm and determination.
He gazed silently at the brilliant Sun and whispered, "If I'm all that's left in the Solar System, then I will be the one to protect our home."
The vast fleet continued its rapid advance. Its survey of the cosmos also continued, never ceasing for a single moment.
Gradually, the fleet crossed Pluto's orbit.
Unfortunately, Pluto was at a different point in its orbit at that moment, so Li Qingsong didn't catch a glimpse of it.
At this point, they hadn't truly entered the Inner Solar System. After all, Pluto had long been stripped of its major planet status and demoted to a dwarf planet.
The outermost major planet was Neptune.
Only by crossing Neptune's orbit would they truly enter the Inner Solar System.
After another long voyage of over a billion kilometers, this time from a distance of several hundred million kilometers, Li Qingsong saw it through his telescope: Neptune, a sapphire-blue orb, like a vast ocean.
After a journey of several years, crossing a vast distance of more than ten billion kilometers, and after an absence of several hundred years, Li Qingsong had finally returned to the Inner Solar System.
The fleet's advance did not stop.
Other than deploying a few probes toward Neptune, Li Qingsong made no other stops.
His goal remained fixed on the planet ahead: Jupiter, the largest in the Solar System.