Sunday, October 10, 2021

G__D ENABLED BULLYING
Gas Giants May Have Bullied Planet 9 to the Fringes of Our Solar System
ANTHROPOMORIC COSMOLOGY


Caroline Delbert
Fri, October 8, 2021

Photo credit: Steven Hobbs/Stocktrek Images - Getty Images

A smaller planet more like Earth or Mars could have been pushed to the outer reaches of our solar system (or into deep space), according to a new paper.

Scientists think Planet 9 used to be more like Planet 6 or 7—meaning it once swirled among the gas giants before they ultimately kicked it out of orbit.

The solar system has three zones: inner planets, outer planets, and what's beyond.

Scientists believe that there could be a ninth planet in our solar system, lurking somewhere beyond Neptune—but don't get too excited, because this isn't about Pluto.

Rather, this is the story of a mysterious Earth- or Mars-sized planet that may have swirled beyond the asteroid belt, among the gas giants, before they ultimately swept this potential "Planet 9" toward the outer reaches of our solar system ... or even into deep space. The theory makes sense on its face: Jupiter is kind of known as a bully, after all.

That's according to two researchers from the University of British Columbia and the University of Arizona who have studied various computer simulations depicting the evolution of our solar system. Their findings are outlined in a new paper, published last month in the Annual Review of Astronomy and Astrophysics.

In it, the scientists speculate that there's something missing in those models, like the fact that our solar system would have four gas giants in a row (Jupiter, Saturn, Uranus, and Neptune) and then no other planets after that other than small, irregular dwarf planets like Pluto.

"Logic suggests there should be some planets of other sizes, and their simulations back them up," Phys.org reports. "Adding another Earth- or Mars-sized planet to the outer solar system, perhaps between two of the gas giants, produces a more accurate model—at least during the early stages of development."

The new research focuses on the the initial position of this "Planet 9"—a common name for the loose collection of hypotheses about a potential ninth planet outside the main area of our solar system. Planet 9 could be a black hole, for instance, or it could be 10 times the size of Earth.

Specifically, the paper zooms in on the possibility that the four gas giants pushed Planet 9 to the outer reaches of the solar system. Planets exercise gravity on each other, which is partly why experts suspect that Planet 9 exists in the first place.

How would the gas giants shove out a much smaller, much denser planet, then? Jupiter especially already acts like a linebacker in orbit, deflecting smaller objects like comets or meteors as they approach the solar system. (This is one of many reasons a Melancholia-like rogue planet is extremely unlikely.)


Photo credit: NASA

The scale of our solar system appears even larger when you consider where Planet 9 is roughly believed to exist. First, there is the inner planets zone, where Mercury, Venus, Earth, and Mars are packed relatively tightly together. After that is the Kuiper Belt, full of icy rocks and other small items.

From there, the scale zooms way out to accommodate Jupiter, Saturn, Uranus, and Neptune, all gas giants that are spread much further apart. Neptune may appear small among these titans (see the image above), but is still many times Earth's mass, and large enough to fit 57 Earths inside by volume.

After that, Pluto is the star of the so-called third zone, a huge expanse dotted by, so far, just dwarf planets and other celestial bodies like comets. This is where scientists get stuck, because it seems so unlikely that the evolution of our solar system would cough up just four very similar gas giant cores and then stop.

How do we actually find Planet 9 if it exists? These scientists posit that increasingly more powerful telescopes could bring us some closure in the near future. If not, one string theorist proposed something a little wild last year: an array of tiny probes that would blanket the third zone in order to shake loose any items—like larger planets or even the primordial black hole—that some scientists believe is Planet 9.

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