Study finds that a giant planet may have “escaped” from our solar system

Although Pluto has lost its status as “Planet Nine“When the classification was downgraded to a dwarf planet, there is ample evidence that our solar system either had or She currently has A large planet far from Pluto may one day claim the former Pluto mantle and become Right ninth planet. The unusual regular orbital patterns observed in the Kuiper Belt indicate that some celestial bodies larger than Pluto lurk just outside the distant band of icy debris at the edge of the Solar System where Pluto, Eris and the other dwarf planets live.

The hypothetical existence of distant Planet Nine, or ‘Planet X’, is still controversial, but evidence continues to grow in its favor. Certainly, this wouldn’t be the first time that a hypothetical planet had been found. Neptune was the first planet to be found by studying the orbits of other bodies in the solar system. Interestingly, its location was discovered by predictions drawn from pen and paper accounts about telescope observations.

Unintentionally, modern astronomy paper Nature has found that there is a high probability that a gas giant, similar to those in the outer solar system, was rapidly ejected from its orbit around the sun early in the evolution of the solar system. The presence of the “missing” Planet Nine so early in the formation of the Solar System’s history would explain much of how and why the Solar System looks like it does today.

Related: What scientists know so far about the ninth planet

To model the birth and evolution of possible star systems, the team of collaborating scientists from China, France and the United States ran nearly 14,000 simulations of the early solar system to see what it came to look like today, with four Earths. The planets and the asteroid belt orbit close to the sun, four gaseous planets orbit farther away, and cold, rocky bodies are scattered behind the gas giants.

Interestingly, the simulations strongly indicate the presence of early instability in the orbits of the giant planets – Jupiter, Saturn, Uranus, Neptune and possibly the ninth planet. Such objects would have been much closer to the primordial Sun at some point, before gas coalesced into the Sun and actually caused powerful fusion reactions that expelled gas and dust outward, including the aforementioned planets. Scientists believe that this resulted in a rapid and chaotic displacement into their current orbits.

Simulations indicate that in the early days, the gas giants had very circular and regular orbits at regular intervals from the Sun; After the budding star began to compress them outward, they experienced an unstable transition from compressed orbits to orbits aligned with the plane of the disk to current orbits.

Mr Seth Jacobson of Michigan State University, who was involved in the study, described this as a “global source of planetary instability in the galaxy.”

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“We think all disks go through this, which is what astronomers call the transition disk phase, where the disk is optically evaporated from the inside out,” Jacobson told Salon, referring to the protoplanetary disk of gas and dust that previously painted (and all) solar systems. . We can see nascent solar systems forming around the galaxy in the same way, indicating a similar pattern to how all solar systems form.

“What’s really remarkable is that extrasolar astronomers have already confirmed that a very high percentage of giant gas systems as well as super-Earth systems have gone through planetary system instability, and we think the solar system is similar,” Jacobson continued.

Inside a collapsing cloud of stellar debris – a gaseous solar nebula and possibly a dead supernova remnant – our primordial sun is starting to turn on the heat. Heating of ionized gaseous elements in the disk, and the emission of energetic photons from our young Sun, eventually led to gas being expelled from the protoplanetary disk by evaporation.

The inner edge of this gaseous disk would theoretically “pull” the planets with it as it expanded outward. Jacobson said the initial location of the gas giants in the inner solar system would be “a very strong catalyst for instability.” This could have caused a Planet Nine-type world to be ejected from the solar system forever.

In fact, in 90% of the simulated scenarios, this instability was triggered. The orbits of the planets have been stable for billions of years in our solar system. However, the mystery of the early development of our solar system remains unclear. The location of the Trojan asteroids of Jupiter and the irregular satellites of the giant planets indicate a chaotic redistribution as with the diverse composition of the Earth and its moon, which requires a great deal of mixing between the different bodies. (that it widely believed that a Mars-sized object called Theia collided with the early Earth, and the ejected material formed the Moon.)

Experts now realize that the timing of the giant planet’s migration has been a problem. The geological evidence is also radically outdated for this model’s time scale, known as the “Nice” model (as in Nice, France): Specifically, a series of three papers appeared in one issue of Nature that laid out a solution, suggesting in The Origin to the Giant Planet instability occurred approximately half a billion years after the formation of the Solar System, and would have depended on the gravitational encounter between two planets to trigger a series of destabilizing reactions.

“Instability will always occur very early in the history of the solar system after a few million years from its inception,” Jacobson added. “The Sun was still in its constellation at the time. If there was an ejected ice giant, this ice giant might not have already been ejected. It might have been captured in this elliptical orbit.”

If the expulsion is too late, it will likely turn out to be a rogue planet. In this motion scenario, starting with 10 million years of formation instead of 500 million years in the age of the Solar System, the incubation stellar cluster The system can be born in the interception of the runaway planet. The result is an extended elliptical orbit.

“During the lifetime of a protoplanetary nebula disk, the amount of gas in the disk decreases over time,” Jacobson emphasized. “Only when the disk has really gotten the amount of gas in the disk really low can the photoevaporation effect occur. Then the photoevaporation effect moves very quickly. The phase of the transition disk is actually very short and clears the disk from the inside out.” The effect is similar to that of a puddle of water around the stove, as the water near the fire evaporates quickly and takes a little longer.

Jacobson said the motion of the planets was a surprising result of the simulation. “What I think we didn’t even fully appreciate until after we started this simulation is that there’s still enough gas in the disk and that process still takes enough time that it can significantly impact the planet’s orbits while the process is happening,” Dunn is.

Why does the solar system look like it is: