Tom had always been curious about the Oort Cloud.
That is, does the Oort Cloud really exist?
Although various solar system evolution theories support the existence of the Oort Cloud, and some celestial bodies suspected to be from the Oort Cloud have been discovered within the solar system, such as comets and asteroids, the true Oort Cloud has never been observed by humans, nor by Tom.
It is estimated that among the celestial bodies in the Oort Cloud, those with a size of 1 kilometer or more could number in the trillions, and even those with a size of 20 kilometers or more probably number in the billions.
The total mass of Oort Cloud celestial bodies adds up to more than five times the mass of Earth.
More than five Earths' worth of mass is thus scattered at the edge of the solar system, never having been seen by anyone.
It seems difficult to understand how so many celestial bodies and so much mass have never been seen. But in fact, the reason is very simple.
