While it is out in space the 12th Planet moves slowly, but increases speed rapidly as it comes close to one of its two foci. When the 12th Planet is passing your Sun it is moving rapidly, the time spent within your outer planet Saturn's orbit a mere 3 months [Note: see 2003 Date explanation]. It zips by.
It does not head directly into the Sun, as there is a play between attraction and repulsion which exists between all planetary bodies. The distance maintained is determined by these forces, relative to the mass and speed of the two objects - your Sun and the passing 12th Planet. All comets tracked do not have a mass sufficient to trigger a strong repulsion force in the planets they pass or the Sun, and thus the humans ephemeris assume the only elements to consider are the path and the speed. For a tiny comet, if the path is such that it brings the comet too close to a planet, there is a collision, as the repulsive force generated in a planet is not strong enough to repulse a tiny comet. Thus comet orbits assume that the comet is simply slinging toward the Solar System, and this math works due to their relatively tiny size. Humans assume that if on the initial orbit into the Solar System the result was such that the tiny comet headed into the Sun, they did not become a regular visitor, a returning comet. However, in the case of the 12th Planet, which has a mass much greater than the Earth, the repulsion force is a factor. Mathematically this is equal to the force of gravity when the two objects are close enough to touch, or they would in fact touch.
Simply stated, the faster the 12th Planet moves, the closer it can come, although the math in this matter is not quite that simple. Where it would seem that the 12th Planet is coming dead on, and in fact month after month and even year after year would be found in approximately the same place in the skies, nevertheless, as it approaches your Solar System, things change. The 12th Planet is both attracted and repulsed by your Sun. Why is it that comets do not just head for the Sun, and there stop? This is not a one-way issue. Both factors are at play. Thus, as the 12th Planet approaches your Sun, it picks up speed but also shies away. There is a battle going on, a tug in one direction with a push in another. The end result is that the 12th Planet still comes on, full bore, but veers to the side a bit as it approaches. As it is still picking up speed, the speed compensates for the repulsion, and the 12th Planet finds in the last few months that it can now come closer to the Sun, the repulsion being balanced by the speed.
Thus, when it gets to its maximum speed, entering your Solar System, it bends in toward your Sun, after having veered outward slightly, so that the angle is approximately 32 degrees. This angle can vary slightly depending on influences upon the 12th Planet in its long journey away from your Sun. For this passage, the 12th Planet's first pass will be at a time when the Earth is on the same side of the Sun as the 12th Planet's point of passage, but toward the rear of the Sun. Thus the 12th Planet will come into the Earth's orbital plane not directly between the Earth and the Sun, but forward, somewhat closer to the 12th Planet's approach. When one is looking toward Orion, at this time, from above the Earth's orbital plane, the perspective human astronomers prefer, the Sun will be to the right. The Earth, Sun, and 12th Planet will thus Form a Triangle in the Earth's orbital plane with a 23 degree angle at the Earth, an 18 degree angle at the Sun, and a 139 degree angle at the 12th Planet. It is at this point, essentially, that the 12th Planet is closest to the Earth, as with the angle of entry into the Earth's orbital plane being 32 degrees at this point, the 12th Planet essentially dives up through the Earth's orbital plane and quickly passes on.
The 12th Planet pulls down and away from your Sun only at the last minute. This is reflected in time as the last 9.7 weeks or 68 days [Note: see 2003 Date explanation]. This is reflected in distance as 1.2598 times the orbital diameter of Pluto, or two and one-half times the distance from your Sun to this farthest known planet which you call Pluto. The shape of the deviation is parabolic at the angle of turns, in all cases. This is not exact, but for purposes of calculating an orbit is something you can work with that will be close enough. Thus, the 12th Planet starts its deviation from its straight path in a parabolic manner, but has scarcely started to turn away when its increasing speed allows it to come closer to the Sun and it does another parabolic curve back toward the Sun, essentially correcting its path again to be straight toward the Sun. When it passes the Sun, piercing the Earth's orbital plane, it has come to the point in a parabolic curve where the line is essentially straight.
The distance of deviation from the orbital line, which is essentially a straight line toward the Sun on the approach, is not great, approximately 37 million miles. This relatively slight distance is enough to grant the 12th Planet the sharper angle it seeks. At this point the orbit of the 12th Planet has been altered, as the Sun is the only giant it is listening to. The 12th Planet maintains this line of orbit as it leaves the Solar System and travels out. In the scheme of things, this puts a slight lift in the orbit, as though the orbit between the two foci were your arm, extended out from your body, and the part of the orbit past the Sun were your hand. If you lifted your hand at the wrist slightly, a 21 degree lift, you would simulate what the 12th Planet's orbit is doing at this point. The 12th Planet maintains this deviation until it again passes your Sun, the second pass. It does not find it necessary to pull away from the Sun on this second pass, as the angle is correct to begin with.
It should be understood that the reason for the deviation in the first place is that the other planets in the Earth's orbital plane are also entering into the equation. The 12th Planet in essence pulls away from this orbital plane, as well as from the Sun. It does not want to move in along side the other planets, it wants to cross quickly at a sharper angle. Thus, the return orbit is comfortable in this regard. Having passed the Sun again on the second pass, and moving far enough from the Sun and the planets in the orbital plane to feel free of their influence, the 12th Planet again begins to listen to the second foci. Thus, it again makes a parabolic curve to head straight toward the second foci. Here the 12th Planet is somewhat further from the Sun than the measurement we have mentioned for the approach, as the second foci is farther away and has less influence at this point.