UCSC: Wandering Jupiter Accounts for Unusual Solar System

[bystander]

Wandering Jupiter Accounts for Our Unusual Solar System
University of California, Santa Cruz | 2015 Mar 23

[i]This diagram shows the orbital distribution of extrasolar planets smaller than Jupiter that have been detected by the Kepler mission, in comparison to the orbits of Mercury, Venus, Earth, and Mars. Most of these extrasolar planets are much closer to their host stars than the innermost planets of our solar system are to the sun. [b](Credit: Batygin and Laughlin, PNAS)[/b][/i]

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Jupiter may have swept through the early solar system like a wrecking ball, destroying a first generation of inner planets before retreating into its current orbit, according to a new study published March 23 in Proceedings of the National Academy of Sciences. The findings help explain why our solar system is so different from the hundreds of other planetary systems that astronomers have discovered in recent years.

"Now that we can look at our own solar system in the context of all these other planetary systems, one of the most interesting features is the absence of planets inside the orbit of Mercury," said Gregory Laughlin, professor and chair of astronomy and astrophysics at UC Santa Cruz and coauthor of the paper. "The standard issue planetary system in our galaxy seems to be a set of super-Earths with alarmingly short orbital periods. Our solar system is looking increasingly like an oddball."

The new paper explains not only the "gaping hole" in our inner solar system, he said, but also certain characteristics of Earth and the other inner rocky planets, which would have formed later than the outer planets from a depleted supply of planet-forming material. ...

Planet hunters have detected well over a thousand exoplanets orbiting stars in our galaxy, including nearly 500 systems with multiple planets. What has emerged from these observations as the "typical" planetary system is one consisting of a few planets with masses several times larger than the Earth's (called super-Earths) orbiting much closer to their host star than Mercury is to the sun. In systems with giant planets similar to Jupiter, they also tend to be much closer to their host stars than the giant planets in our solar system. The rocky inner planets of our solar system, with relatively low masses and thin atmospheres, may turn out to be fairly anomalous. ...

New Research Suggests Solar System May Have Once Harbored Super-Earths
California Institute of Technology | 2015 Mar 23

Jupiter’s decisive role in the inner Solar System’s early evolution - Konstantin Batygina, Greg Laughlin

• Proceedings of the NAS (online 2015 Mar 23) DOI: 10.1073/pnas.1423252112

[Nitpicker]

That's a very non-linear graphic in the radial direction (a log scale, at a guess, without thinking too much). Mercury has a semi-major axis of almost 0.4 AU, but it looks about twice that in the graphic.

It would also be interesting to see this diagram re-scaled in relation to the "Goldilocks zone" and the frost line of each star, rather than just the distance.

[Ann]

I found this hugely interesting. As some of you know, I have this gut feeling that the Earth is truly unusual even in a cosmic sense. By that I don't mean that life in the universe is unusual, because I can't know anything about that. But suppose that most planets inside their suns' habitable zones are super-Earths with thick atmospheres. What would the Earth had been like if it had been twice as massive as it is and had had an atmosphere as massive as the atmosphere of Venus? It would still have been inside the habitable zone of the Earth. Would it have had liquid water? I don't know. Would it have had life? I don't know. But if it had had life, would it have had complex life forms even remotely similar to ourselves? Perhaps. But could such an Earth have supported us humans, even a modified sort of humans? I strongly doubt it.

I searched the web for images of the sort of sturdy life forms that might exist on a super-Earth with a thick atmosphere. Would this guy have been happy living on a planet like that?

Ann

[geckzilla]

I found this hugely interesting. As some of you know, I have this gut feeling that the Earth is truly unusual even in a cosmic sense.

Katie Mack was posting the other day about how even in our own solar system, Earth is weird for wearing its oceans on top. Everyone else has their oceans on the bottom.

Would this guy have been happy living on a planet like that?

How rude.

[Ann]

I found this hugely interesting. As some of you know, I have this gut feeling that the Earth is truly unusual even in a cosmic sense.

Katie Mack was posting the other day about how even in our own solar system, Earth is weird for wearing its oceans on top. Everyone else has their oceans on the bottom.

Would this guy have been happy living on a planet like that?

How rude.

Katie Mack pointed out another amazing aspect of our wonderful planet.

But I didn't get the "rude" thing. Am I missing something?

Ann

[Nitpicker]

Can't quite put my finger on it ...

[Ann]

You mean he looks like a f**k sign?

But don't we all, with our heads sort of raised in the middle?

Ann

[geckzilla]

Well, you know, the eyes and eyebrows are shaped like a fingernail, the mouth is conveniently located on the finger joint, the shoulders are conspicuously asymmetrical like index and ring finger knuckle joints... Yes, very rude alien indeed.

[BMAONE23]

Reminded me of these guys

Click to play embedded YouTube video.