New Planet!?

Astronomers have possibly discovered a new planet in our solar system!  This was announced earlier this year, so you may have heard the news already.  If not, then I'm glad you heard it from me!  The discovery was made by a team of astronomers at Caltech, which was led by Mike Brown.  He is also a professor of Planetary Astronomy there.

While the planet hasn't been seen directly, based on orbits of many objects in the Kuiper Belt and computer simulations, a large planet is the most likely cause.  The simulations are created using the known values (altered orbits of Kuiper Belt objects) and using unknown variables such as the object that has altered these orbits.  The Kuiper Belt is similar to the Asteroid Belt which lies between Mars and Jupiter, only it is between 30 and 50 AU (Astronomical Units) from the Sun.  Remember, an AU is the average distance between the Sun and the Earth (approximately 93 million miles).  The Kuiper Belt also contains objects much larger than asteroids,  the most popular of which is Pluto.  

Since Pluto is no longer considered a planet, this hypothetical planet has been designated as Planet 9 until a proper name is assigned to it.  The estimated orbital period for this planet is 15,000 Earth years.  The planet would likely have to be slightly smaller than Neptune or 2-4 times the size of Earth to cause the disturbances of the objects in the Kuiper Belt that have been recorded.

The planet hasn't been discovered yet because it likely lies, on average, approximately 700 AU from the Sun and has a highly elliptical orbit. Since the orbit is highly elliptical, the closest approach to the Sun could be around 200 AU while the furthest it could reach away from the Sun is 1,200 AU. The known planets that orbit the Sun, have the Sun at the center of their orbit while this new planet likely will not.  This can be caused by the Sun capturing this planet from a passing star that has planets orbiting it. Perhaps it was a rogue planet that had lost its parent star but has found an adoptive star.  The planet could have also been a member of our solar system all along but had its orbit altered by a passing star.

As you can see, there are a lot of unknowns and as mentioned, it might not be a planet at all. But the planet theory is the best fit based on the data and the computer simulations.  I think it would awesome if a new planet is discovered in our solar system!

For now, astronomers are still running simulations and also focusing large telescopes on the night sky to see if they can detect this planet.  The estimated area of the sky that the planet could be right now is towards the outstretched arm of Orion.  It may take months or even years to detect this planet, if it's out there.  I'm hoping that it is out there, and that it will be found soon!