Lost: one giant planet

Computer simulations of the early solar system suggest the possibility that our system had more than four giant planets initially and that one was ejected as the solar system settled into its current form. Dr. David Nesvorny’s hypothesis, published in The Astrophysical Journal Letters, depicts the early solar system as a chaotic place, with planets and moons buffeting each other in wildly unstable orbits.

“We have all sorts of clues about the early evolution of the solar system,” says Nesvorny, of the Southwest Research Institute. “They come from the analysis of the trans-Neptunian population of small bodies known as the Kuiper Belt, and from the lunar cratering record.” These suggest that the orbits of the giant planets were affected by a dynamical instability when the solar system was only about 600 million years old. As a result, the giant planets and smaller bodies scattered away from each other.

Some small bodies moved into the Kuiper Belt and others traveled inward, producing impacts on the terrestrial planets and the Moon. The giant planets moved as well. Jupiter, for example, scattered most small bodies outward and moved inward.

But this scenario presents a problem. Slow changes in Jupiter’s orbit, such as the ones expected from interaction with small bodies, would have conveyed too much momentum to the orbits of the terrestrial planets, stirring up or disrupting the inner solar system and possibly causing the Earth to collide with Mars or Venus.

“Colleagues suggested a clever way around this problem,” says Nesvorny. “They proposed that Jupiter’s orbit quickly changed when Jupiter scattered off of Uranus or Neptune during the dynamical instability in the outer solar system.” The “jumping-Jupiter” theory, as it is known, is less harmful to the inner solar system, because the orbital coupling between the terrestrial planets and Jupiter is weak if Jupiter jumps.

Nesvorny conducted thousands of computer simulations of the early solar system to test the jumping-Jupiter theory. He found that, as hoped for, Jupiter did in fact jump by scattering from Uranus or Neptune. When it jumped, however, Uranus or Neptune was knocked out of the solar system. “Something was clearly wrong,” he says.

Nesvorny then considered whether the early solar system could have had five giant planets instead of four. By running the simulations with an additional giant planet with mass similar to that of Uranus or Neptune, things suddenly fell into place. One planet was ejected from the solar system by Jupiter, leaving four giant planets behind, and Jupiter jumped, leaving the terrestrial planets undisturbed.

“The possibility that the solar system had more than four giant planets initially, and ejected some, appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, indicating the planet ejection process could be a common occurrence,” he concluded.

Related:
Discuss this article in our forum
Astronomers detect distant solar system with five planets
Astronomers cop an eyeful of giant planet’s demise
Sol System “Pretty Special,” Say Astronomers
Solar System’s “Bouncing” Linked To Mass Extinction Events

Source: Southwest Research Institute

, ,

Comments are closed.

18 Vintage Postcards Oshkosh, Wisconsin, early 1900s picture

18 Vintage Postcards Oshkosh, Wisconsin, early 1900s

$20.00



Vintage Early Porcelain Beer Bottle Stoppers & Bail Wire Pre-Prohibition Blank picture

Vintage Early Porcelain Beer Bottle Stoppers & Bail Wire Pre-Prohibition Blank

$5.99



Qposket Early Sailor Moon Disney Princess Bulk Sale picture

Qposket Early Sailor Moon Disney Princess Bulk Sale

$47.73



THE THING #26 CGC 9.8 NM/MT WHITE PGS EARLY TASKMASTER APPEARANCE MARVEL COMICS picture

THE THING #26 CGC 9.8 NM/MT WHITE PGS EARLY TASKMASTER APPEARANCE MARVEL COMICS

$55.00



29 Vintage Postcards Milwaukee, Wisconsin, early 1900s picture

29 Vintage Postcards Milwaukee, Wisconsin, early 1900s

$35.00



Kurt S. Adler The Early Years Reproduction of The Nostalgic Color Wheel - Vin... picture

Kurt S. Adler The Early Years Reproduction of The Nostalgic Color Wheel - Vin...

$32.95



Early example of the work of Leonard Misonne 1870-1943 Winter 1910 picture

Early example of the work of Leonard Misonne 1870-1943 Winter 1910

$9.20



Viewmaster Single Reels - early Numbers 282 thru 351 US Travel scenes, YOU PICK picture

Viewmaster Single Reels - early Numbers 282 thru 351 US Travel scenes, YOU PICK

$4.00



Rare Early 1900s Gooderham & Worts Whiskey Advertising Bottle Opener / Corkscrew picture

Rare Early 1900s Gooderham & Worts Whiskey Advertising Bottle Opener / Corkscrew

$45.00



vtg Christopher RADKO ornament MUSHROOM SANTA #96-212 Early RARE glass large 8

vtg Christopher RADKO ornament MUSHROOM SANTA #96-212 Early RARE glass large 8"

$199.00



Powered by WordPress. Designed by WooThemes