1500 years ago, everybody knew the Earth was the center of the Universe. 500 years ago, everybody knew the Earth was flat… Imagine what you’ll know tomorrow.
Agent K (Tommy Lee Jones) in the movie Men in Black
We have moved on! From the days when we humans had a simple thought. That is, everything above is heaven and everything below is hell. When we were sure that the afterlife existed and it existed either in the sky above or the ground below. We have moved on from the time when the universe was centered around the earth and the sun, the moon, and the planets went around in perennial circles around the earth. Circles, mind you, circles.
We have moved on from the time when stars were stationary and if they appeared to move, it was because of the movement of the earth.
Then came Kepler, with his laws of planetary motion and we understood that the planets moved in an ellipse around the sun. Newton then came up with the law of universal gravitation. This was a major breakthrough in the way we thought about the solar system, and in general about space itself.
We discovered the nine planets orbiting the sun. Ahem, eight. Until now! Poor Pluto was kicked out of the team for being too small(Yeah, I know! These scientists are bullies).
Planets, starting from Mercury to Saturn were all discovered as early as the 17th century. Actually, the planets till Saturn were observed in ancient times. But Galileo was the first to observe it with a telescope in the year 1610.
Uranus was the first planet to be discovered in the new age. It, like many scientific discoveries, was discovered by accident. It was discovered on 13th March 1781 by William Herschel. Herschel was performing a survey of all stars of at least magnitude 8 — from slightly too faint to see with the eye. That’s when he noticed a very faint object — only barely within the limit for viewing with the eye — that moved in front of the fixed stars. Hence, it had to be closer to the earth than the stars he was observing. At first, he thought it was a comet.
Later, he and others realized it was a Planet doing its thing around the sun. Much later it was observed that Uranus has a ring system, though not as complicated as the beautiful Saturn.
The discovery of Neptune is quite interesting. It was predicted mathematically before it was directly observed. Alexis Bouvard, in the year 1821, published the astronomical tables for the orbit of Uranus. It predicted the position of Uranus in the future. It was based on Newton’s laws of motion and gravitation. However, over time, the observed results started deviating from the predicted path.
The irregularities, both in the planet’s ecliptic longitude and in its distance from the Sun, or radius vector, might be explained by a number of hypotheses: the effect of the Sun’s gravity, at such a great distance might differ from Newton’s description; or the discrepancies might simply be observational errors. Or, maybe not!
Bouvard, a sound theoretical astronomer, was so confident of his equations and predictions that he stated that his equations were perfect and the observers were the ones causing the errors in the relative observations. Damn! There were discrepancies noticed right from the year 1820 to 1845, where the orbit of Uranus deviated further and further from the predicted path.
The discrepancies, that we are talking about here is basically the speed of Uranus around the sun. It was moving at different speeds based on its position around the sun. So, he figured out that there had to be something out there responsible for this because the mathematics was spot on. Finally, when Bouvard had enough of this bullshit, he took all the data about the discrepancies and gave it to an astronomer(Le Verrier) and told him that there must be another planet.
It took Le Verrier a while to figure it out, but he eventually came up with the maths required to fit the positions. Before we get into the details, let us step back and analyze why this happens. First thing first, two objects attract each other because of gravity. Suppose Uranus is moving at a certain speed. But over time, the observations showed us that Uranus was moving at a slower speed in some places in its orbit.
The only possible explanation for this is the gravitational influence of an external entity, near the position of Uranus where it had slowed down. It had to be a celestial body of considerable mass to alter the speed of an object as massive as Uranus. Hence, it could not be a comet. The only other possibility was the presence of a NEW planet. A new planet, beyond the orbit of Uranus. He sent his predictions to the observatory in Berlin. The folks at the observatory pointed their telescopes in the direction predicted by Le Verrier that very night, and voila, found Neptune that very night.
The discovery of Pluto is another interesting story in itself.
Why am I saying all this? Well, here comes the best part.
That’s because we may be on the verge of discovering a new planet. Well, scientists have predicted the presence of another planet lurking in the solar system. We may finally have nine planets in the solar system, after demoting Pluto to dwarf planet. Yayy! And why is this so exciting? Let us take a look at the big picture here.
All the planets from Mercury to Saturn were found very early. The three new major breakthroughs we witnessed as humans, as a whole species is the discoveries of Uranus, Neptune, and Pluto. Pluto is not a planet anymore. Well, technically, we discovered rings on Saturn in the 1600s when Galileo pointed his telescope to the skies.
But the point is, we already knew about the existence of Saturn much earlier, centuries ago. Damn it, it was visible to the naked eye. There are only a handful of generations of humans that have witnessed a planet being discovered in the solar system. We may be one of them! That is exciting, isn’t it? What’s more? We will be going on the journey together.
Yes, we are aware of the predictions. We are all excited to find the Earth’s distant cousin. Just like driving a car to a far away place, without having navigation on our mobile phones. Sometimes, we are gonna be disappointed every time we realize we have taken a wrong turn or hit a dead end and have to turn back. But we are also gonna be happy when we get a step closer or we make a right decision, taking us one step closer to the discovery of the new planet.
We, as a human race are seeing some crazy things in space. We can “see” black holes which are in other galaxies, neutron stars, pulsars, planets, stars, galaxies which are thousands of light years away. But, we are not sure about the existence of a planet in our very own neighborhood, our solar system. This is equally riveting and mind numbing at the same time.
Now, coming to planet nine(Yes, finally!), why all the hype now? Why are so many people talking about it? Astronomers have made an interesting discovery. There is actually more than one phenomenon in the solar system that cannot be explained with our present knowledge of the solar system and the space around it.
“There are now five different lines of observational evidence pointing to the existence of Planet Nine,” Konstantin Batygin, a planetary astrophysicist at the California Institute of Technology (Caltech) in Pasadena, said in the statement. “If you were to remove this explanation and imagine Planet Nine does not exist, then you generate more problems than you solve. All of a sudden, you have five different puzzles, and you must come up with five different theories to explain them.”
There are 5 reasons why astronomers believe another planet is waiting to be discovered. Let’s start…
Here is reason number 1.
SEDNA! Sedna is a dwarf planet that orbits farther away from the orbit of Pluto. It’s closest approach to the sun is far greater than Pluto’s distance away from Earth. It’s not easy for a planet to form so far out there in the solar system. And planet nine might have played around with the orbit of Sedna. Sedna’s orbit is extremely elongated, which is quite different from the circular planetary orbits that feature in our solar system.
Sedna was discovered by a team led by Mike Brown, an astronomer at the California Institute of Technology. “So the zeroth-order piece of information is that, somewhere out there, something perturbed Sedna, and that thing is no longer there. Now, that thing could’ve been another planet; it could have been a star that came close to the sun; it could have been a lot of stars if the sun was born in a cluster,” Brown said.
So, some other body should have influenced it. The only close and massive enough to influence it is Neptune. But, Neptune is still too far away from it to influence it. So, there must be another massive planet hiding somewhere that was responsible for the eccentricity in the orbit of Sedna, which has changed over millions or billions of years.
The predicted path of Planet Nine, actually comes close enough to the orbit of Sedna, that it can influence it and set it in its current orbit. The simulations run by various scientists and astronomers illustrate this. To beef up the theory further, there are 6 other objects that have very similar orbits. Namely 2012VP113 nicknamed Biden, 2004VN112, 2007TG422, 2010GB174 and 2010GP13. These dwarf planets too, like Sedna, may well have been influenced by Planet Nine.
Reason 2 still includes the same dwarf planets.
The inclination of the mentioned dwarf planets is quite similar to each other and at the same time, very different as compared to the other planets in our solar system, which orbit the same star, our SUN!! This is very unusual. That is because the planets tend to orbit along the same path.
If our solar system is put on a plane with the orbit of the earth at zero degrees, the other known planets of the solar system, up to Neptune are only a few degrees apart in their orbital planes. Pluto, an ex-member of the solar system has a steeply inclined orbit. Its orbit crosses the path of Neptune’s orbit. But the two of them never collide, as though they are in some sort of agreement. This phenomenon is called as orbital resonance. But, Pluto apart, all the other planets appear to be on the same plane. But, the orbits of the above-mentioned dwarf planets are quite different. They are roughly tilted by 30 degrees.
We are not talking about one object here, to consider it an anomaly. All these dwarf planets have the similar inclinations. This should have been caused by another massive object, over millions of years. Simulations run by scientists seem to agree that, Planet Nine is the most probable explanation for the tilt in the orbits of these dwarf planets. Over millions of years, Planet Nine pulled these dwarf planets and changed the inclination of their orbits. Another interesting observation is that the inclination of their orbits is similar, indicating that they were all pulled by the same object with the same amount of force. Planet Nine might well be the likely culprit.
The third reason…
Although not very convincing is the tilt in the orbits of planets of our solar system itself. Although the variations are small, the variations do exist.
A look at the table shows that the inclination is in the same direction. It’s not random. Ideally, these planets should not have an inclination at all. It means another object is pulling these planets in a particular direction. The object we are looking for maybe Planet Nine.
The fourth reason…
Is the existence of other less massive objects which are strongly affected by the gravitational pull of Planet Nine. Going by the inclinations observed in Sedna, Biden and the other dwarf planets, scientists hypothesized the existence of other objects that may have even more inclined objects, maybe even 90 degrees. And, over the past few years, a number of such objects have been found(Umm, yeah. Far far away!). Most of them are tiny planets or asteroid-like objects. Since most of them are small, the gravitational pull of Planet Nine influences their path of orbit greatly.
Adding to that, which you may consider as reason 5,
The presence of objects that move in the opposite direction as compared to the general flow of the solar system. Though there is no up or down in space, if you consider, the movement of most objects in the solar system as counterclockwise, there are some objects which orbit the sun in a clockwise direction.
The likely explanation for this anomaly is that the influence of Planet Nine over millions of years on these objects, gradually pulled them into an inclined orbit, into 90 degrees orbit and then slowly, over long periods of time, Planet Nine will make the entire solar-system plane process(a change in the orientation of the rotational axis of a rotating body), or wobble, just like a top on a table.
So, what do we know about(ahem, we think we know!) about Planet Nine? It is a massive planet, estimated to be 10 times as massive as our Earth. The orbital period of Planet Nine is estimated to be about earth 15,000 years(Yes. That long). It may have a radius about 4 times that of Earth. That is all we know about it! Damn, that’s frustrating.
And when Planet Nine is finally discovered, we may have an entirely new picture about the origin and evolution of the Solar System. And finally, our horoscopes will be more accurate!! It will be one of the greatest days in the history of mankind.
The Original post is published on NikTalks.com.
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