Why Jupiter Has No Rings

The title is false, Jupiter does have rings, but they are so thin, they are very hard to see, even in the best of conditions.

But why does Jupiter not have big, beautiful rings like Saturn? A recent article I read said Jupiter's moons are to blame. If it didn't have all those giant moons, it would have rings much bigger and more spectacular than Saturn's.

A new study says that giant moons destroy rings before they have a chance to form. And the Galilean moons of Jupiter, one of which is the largest moon in the solar system, seem to be good at it. Therefore, it is unlikely Jupiter ever had large rings at any point.

Massive planets form massive moons, which prevent them from having substantial rings.

Well, I thought the article had more to it than that, but that seems to be the sum total of it.

In a 'related' video, which I didn't watch for lack of time, the headline said Jupiter may have 'eaten' some sibling planets while it was growing. That sound interesting, so I'll keep my eyes open for more on that, but I suspect it will be as thin as Jupiter's rings.

 

https://www.msn.com/en-us/news/technology/scientists-solve-the-reason-why-jupiter-has-no-rings/ar-AAZRF0k?ocid=mailsignout&li=BBnbfcL

Wandering Jupiter

A few weeks ago, I explored the possibilities of what might happen if Neptune's orbit should get jiggled by a rogue sun wandering too close to our system. More recently, I read an article that explains that Jupiter has already done some wandering, in order to be in the orbit it's in.

Jupiter's current orbit averages 5.2 astronomical units (AU = the average distance between the sun and Earth). But researchers now say the gas giant started to form some 18 AU away, which is about twice as far out as present-day Saturn. Furthermore, Jupiter made that journey in about 700,000 years, which is the blink of an eye in astronomical terms.

The idea of a wandering Jupiter is not new; I've heard several theories about it. But this time there is some proof that Jupiter formed a long way from the sun and then migrated inward, and that proof came from the Trojan asteroids that share Jupiter's orbit.

Jupiter has 2 groups of Trojan asteroids that share its orbit around the sun. A large group is in front of the planet, and a smaller group follow it. Researchers ran numerous computer simulations that showed the early solar system through millions of years of evolution by 50-day increments.

The simulations showed that the inward migration of the giant planet always resulted in a larger swarm of Trojans in front of Jupiter than behind it. As Jupiter traveled inwards—propelled by gravitational interactions between the fledgling gas giant and the sun's protoplanetary disk—it created a wide zone of gravitational stability in front of it, leading to more asteroids being caught before it than behind it.

Other simulations that relied on Jupiter forming in its current position resulted in both groups of asteroids being the same size.

One more step to this becoming the solar system we know today.

I can't help but wonder what was happening to Venus, Earth and Mars during the 700,000 years that Jupiter came rolling so much closer.

 

"Trojan asteroids reveal Jupiter's great migration", Astronomy, July 2019