Planet Nine from Outer Space

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Michigan: In Search of the Ninth Planet

Post by bystander » Tue Oct 17, 2017 7:20 pm

In Search of the Ninth Planet
University of Michigan | 2017 Oct 17
A University of Michigan doctoral student has logged two pieces of evidence that may support the existence of a planet that could be part of our solar system, beyond Neptune.

Some astronomers think this alleged planet, called Planet Nine, exists because of the way some objects in space, called "Trans-Neptunian Objects," or TNOs, behave. These TNOs are rocky objects smaller than Pluto that orbit the sun at a greater average distance than Neptune. But the orbits of the most distant of these TNOs—those whose average distance from the sun is more than 250 times as far as Earth's distance—seem to point in the same direction. This observation first led astronomers to predict the existence of Planet Nine.

For these TNOs to be aligned in the orbits they currently occupy because of Planet Nine's influence, astronomers say, they would have been in the solar system for longer than a billion years. However, some astronomers think in that amount of time, some of these objects should have either smashed into another planet, been thrown into the sun, or ricocheted off into space by other planets' gravitational force.

The U-M research, led by Juliette Becker, a graduate student in the Department of Astronomy, consisted of a large set of computer simulations, which uncovered two findings about these TNOs. First, the researchers established a version of Planet Nine that would most likely cause our solar system to look the way it currently does, by preventing the TNOs from being destroyed or thrown out of the solar system. Second, the simulations predict that there is a process that they call "resonance hopping" by which a TNO jumps between stable orbits. This process can prevent the TNOs from being ejected from the solar system. ...

Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine - Juliette C. Becker et al
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Carnegie: Extremely Distant Solar System Object Found

Post by bystander » Wed Oct 03, 2018 3:03 pm

Extremely Distant Solar System Object Found During Hunt for Planet X
Carnegie Institution for Science | 2018 Oct 02
Carnegie’s Scott Sheppard and his colleagues—Northern Arizona University’s Chad Trujillo, and the University of Hawaii’s David Tholen—are once again redefining our Solar System’s edge. They discovered a new extremely distant object far beyond Pluto with an orbit that supports the presence of an even-farther-out, Super-Earth or larger Planet X.

The newly found object, called 2015 TG387, was announced Tuesday by the International Astronomical Union’s Minor Planet Center. ... 2015 TG387 was discovered about 80 astronomical units (AU) from the Sun, a measurement defined as the distance between the Earth and Sun. For context, Pluto is around 34 AU, so 2015 TG387 is about two and a half times further away from the Sun than Pluto is right now.

The new object is on a very elongated orbit and never comes closer to the Sun, a point called perihelion, than about 65 AU. Only 2012 VP113 and Sedna at 80 and 76 AU respectively have more-distant perihelia than 2015 TG387. Though 2015 TG387 has the third-most-distant perihelion, its orbital semi-major axis is larger than 2012 VP113 and Sedna’s, meaning it travels much farther from the Sun than they do. At its furthest point, it reaches all the way out to about 2,300 AU. 2015 TG387 is one of the few known objects that never comes close enough to the Solar System’s giant planets, like Neptune and Jupiter, to have significant gravitational interactions with them. ...

A New High Perihelion Inner Oort Cloud Object ~ Scott Sheppard et al
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor