Does Planet Nine or Planet X exist?

"The hypothetical Planet Nine is imagined as an ice giant in this artist’s conception. Neptune’s orbit is shown as the ellipse around the distant Sun (upper right). Credit: ESO/Tom Ruen/nagualdesign" (Astronomy, Does Planet Nine exist?)

The terms "Planet 9" and "Planet X" mean the strange gravity effect in the Kuiper Belt. That effect causes anomalies in Neptune and Uranus trajectories and it affects also some Kuiper Belt objects. Nobody has seen Planet 9 yet. The interesting thing is how that large object can remain unseen. 

There is a possibility that energy travels to that planet's nucleus which can be colder than its shell. That increases its mass all the time, especially in cases where energy cannot travel out from that planet's shell. 

Researchers predict that the temperature on the planet is about 47 Kelvin. That means -226 degrees Celsius and the absolute zero point is -273,15 C or 0 K. At that point atom movement ends and there is no infrared radiation from that object. 

"The newcomer replacing Pluto presently goes by “Planet Nine.” If and when it finally shows up, it will get the honor of a real name, but so far, the evidence for this hypothetical planet is all indirect. Just as many of the thousands of known planets orbiting other stars have been found by observing their gravitational effects, rather than by actually seeing them, Planet Nine has been identified thanks to the way it has apparently been tugging on a variety of small bodies in the outer solar system and pulling their orbits into lockstep patterns. If it exists, Planet Nine orbits the Sun at an average distance around 550 astronomical units (AU), or 550 times as far as Earth is from the Sun. Astronomers also think it has between five and 10 times Earth’s mass." (Astronomy, Does Planet Nine exist?)

"The orbits of 96 of 109 distant minor planets and extreme trans-Neptunian objects (ETNOs), known as of January 2021, are diagrammed here. The farthest point from the Sun of each is greater than 200 times the distance between Earth and the Sun (1 AU). Orbits colored red are ETNOs aligned with the hypothetical Planet Nine; those colored blue are anti-aligned. The three pink orbits are Sedna and two similar objects. Orbits colored brown are objects that come closer to the Sun than Neptune’s orbit. The predicted orbit of Planet Nine is in yellow. Credit: Nrco0e/Wikimedia Commons" (Astronomy, Does Planet Nine exist?)

Four exotic things that Planet 9 could be. 

1) Black hole. (That can be in far longer distance than 550 times Earth's distance from the sun. That 550 times Earth's distance from the sun is Planet 9 predicted distance from the sun) 

2) Coherent gravity wave

3) Miniature white dwarf. (Planet that pressed into extremely dense form) 

4) Coherent dark energy. (Nobody has seen that thing yet. But it's possible. That dark energy can have a coherent shape, like all other wave movements have). 

The temperature of that planet will be really low and the difference between energy levels on the day- and night sides can make it possible for energy to travel out from its sun side and that can make planet nine or planet X invisible to us. 

The interesting thing is that the very strong gravity effect doesn't cause some anomalies in Uranus, Neptune, and dwarf planet's atmospheres. Also, interesting observations are the X- and gamma-ray flares on Uranus's atmosphere.  That phenomenon can form when something accelerates cosmic particles. 

But can "Planet X" or Planet 9 be something different than we even imagine? There are calculations that Planet X's mass is something between Mars and ten times that of Earth. So could planet 9 be something small and dense? There have been introductions that this mysterious object can be grapefruit-size black holes. 

An interesting thing is that Planet Nine can be a very dense object. All dense objects are not black holes. That means it can be a very tightly packed material. That is far heavier than any material on Earth. That means it's theoretically possible that the large planet can packed to a similar form as some white dwarfs. 

When high-power energy impulse hits the planet it can turn the planet's atmosphere hotter than the planet's nucleus. That effect can push the planet into a small size very dense object. The energy that presses the planet can turn it into a dense object that can have a white dwarf's, neutron star's, or even black hole's density. 

So the object can be very small in comparison with its gravity effect. And that makes it hard to detect. When energy hits an object, its mass will increase. And that thing can mean that something that we think is a dwarf planet can be a dwarf planet with steroids. 

Actually, the mysterious gravitational effect in the Kuiper belt can be something that we even cannot imagine. It can be the coherent gravity wave structure. Or something that we have never seen yet. 

https://www.astronomy.com/science/does-planet-nine-exist/

Cosmic threats are always with us.

"Rogue planets may be numerous in the galaxy, but it surprises most to learn that there are between 100 and 100,000 rogue planets for every star in our galaxy, putting the total number of planets wandering through the Milky Way at somewhere around a quadrillion" (BigThink, Most planets in the Universe are orphans without parent stars)

The planetary defense is a thing. That we should think. The universe including our solar system is full of asteroids and dwarf planets. Some of them are small and we can see them at the last minute. And some of them are seen when they travel past the Earth. But the fact is that. Larger asteroids can cause larger threats than small asteroids. 

If about a 100-meter-size asteroid hits Earth. That will cause very large destruction. It's quite easy to defend cities and Earth against small asteroids. But if the problem is that if some Ceres-size asteroid comes to Earth we see that thing far away. 

And that means we have time to destroy that target. If there is lots of water on the asteroid the large-size nuclear weapon can detonate a hole in the ice that can cover the ocean. And then that erupting water acts like a rocket engine. That pushes the large asteroids away from their trajectories. 

But if a large asteroid like Ceres hits our planet that is the end of life here. In some horrifying scenarios, the large asteroid impacts the moon and then pushes it to impact the course of the Earth. Cosmic catastrophes can wipe any civilization into history and transform any planet into a cosmic molecular cloud. 

One of the threats is the rogue planets. Rogue planets can come into our solar system just like some asteroids. And a big rogue planet can turn the solar system into chaos. 

Most of the planets in the universe might be without parent stars. People call those planets as rogue planets. The rogue planet travels all around the universe. Some of them might be the result of a supernova or nova eruption. But it's possible. The planet can form spontaneously far away from stars, and that means. Rogue planets can be more common than we thought. 

The traveling planets are always a risk to solar systems. If a large, about Saturn-size rogue planet arrives in the solar system, that causes chaos. Those massive rogue planets will pull the asteroids and moons from their trajectory. But smaller rogue planets can also pull things like asteroids from the Kuiper belt behind them. 

The thing is that the threat of rogue planets is real. And if we face a situation where a rogue planet arrives in our solar system. We would need a very powerful tool. That can turn that planet away or crush it. The antimatter bomb can destroy a large planet. And then the laser systems can destroy those asteroids that will travel to our solar system. Or we can just sit and wait for the impact. 

The choice is that we will stand without making a thing. That can mean that the large object can impact Earth. If Earth impacts with a Mars-size planet that will be the end of our world. The thing is that the small rogue planets might be planets that the star explosion pushed away. And large rogue planets can be planets that formed outside the star's gravity field. 

https://bigthink.com/starts-with-a-bang/most-planets-are-orphans/