Study explains why Mars growth stunted

Credit: NASA

A University of Oklahoma astrophysics team explains why the growth of Mars was stunted by an orbital instability among the outer solar system's giant planets in a new study on the evolution of the young solar system. The OU study builds on the widely-accepted Nice Model, which invokes a planetary instability to explain many peculiar observed aspects of the outer solar system. An OU model used computer simulations to show how planet accretion (growth) is halted by the outer solar system instability. Without it, Mars possibly could have become a larger, habitable planet like Earth.

"This study offers a simple and more elegant solution for why Mars is small, barren and uninhabitable," said Matthew S. Clement, OU graduate student in the Homer L. Dodge Department of Physics and Astronomy, OU College of Arts and Sciences. "The particular dynamics of the between the giant planets kept Mars from growing to an Earth-mass planet."

Clement and Nathan A. Kaib, OU astrophysics professor, worked with Sean N. Raymond, the University of Bordeaux, France, and Kevin J. Walsh, Southwest Research Institute, to investigate the effect of the Nice Model instability on the process of terrestrial planetary formation. The research team used computing resources provided by the OU Supercomputing Center for Education and Research and the Blue Waters sustained peta-scale computing project to perform 800 computer simulations of this scenario.

The goal of this study was to investigate simulated systems that produced Earth-like planets with Mars analogs as well. Recent geological data from Mars and Earth indicates that Mars' formation period was about 10 times shorter than Earth's, which has led to the idea that Mars was left behind as a 'stranded planetary embryo' during the formation of the Sun's inner planets. The early planet instability modeled in this study provides a natural explanation for how Mars emerged from the process of planet formation as a 'stranded embryo.'

The success of the terrestrial planetary formation simulations for this study were found to be tied to the detailed evolution of the solar system's two giant planets—Jupiter and Saturn. Systems in the study where Jupiter and Saturn's post-instability orbits were most similar to their actual current orbits also produced systems of terrestrial that resembled the current solar system.

A paper, "Mar's Growth Stunted by an Early Giant Planet Instability," has been published in the online version of the scientific journal Icarus.

Explore further

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More information: Mars' Growth Stunted by an Early Giant Planet Instability, arXiv:1804.04233 [astro-ph.EP]

Matthew S. Clement et al, Mars' growth stunted by an early giant planet instability, Icarus (2018). DOI: 10.1016/j.icarus.2018.04.008

Journal information: Icarus

Citation: Study explains why Mars growth stunted (2018, May 7) retrieved 21 July 2019 from
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May 07, 2018
"....a simple and more elegant solution for why Mars is small, barren and uninhabitable,"....

Huh, I didn't know anyone was permitted to publicly express such an honest evaluation of the Mars data collected too date.

{insert sarcasm font here}

May 07, 2018
Your own, evaluation (however sarcastic) is itself dishonest: No scientist alive would ever argue that Mars is habitable.

Per Kasting, Whitmire & Reynold's oft cited, "Habitable Zones around Main Sequence Stars" Icarus 1993, CO2, H2O and N2 dominated atmospheres and the presence of liquid surface water are the only conditions which define whether or not a planet is habitable; whether a planet has life or not is irrelevant. It still is an open question as to whether Mars has life or not, particularly since the regions which would be most hospitable to known life have been completely unexplored and since Mars was habitable for a time in the distance past.

Amusingly, this paper actually casts further doubt on one of Ward & Brownlee's longtime Rare Earth arguments that Jovian worlds are beneficial to the formation of habitable worlds. Then again, they never claimed life would be rare in the universe, either!

May 08, 2018
S_V, my grumble is that every time there is an article such as this one? Bluntly describing reality. I opinionate here is further evidence against space habitation.

Commentators accuse me of defeatism & being too conservative. What do they base their opinions upon? Speculative fiction and cinematic special effects.

As a concession to "Bold Explorer, Ventures Forth!" hysterics. I point out we have no evidence that biologicals can survive, reproduce & thrive past the Van Allen Belt.

I advocate a concentration of funding and resources on developing an orbiting network of drones, waldoes & robots.

To search out usable materials for constructing the basic infrastructure of automated facilities.

These facilities, would in turn, be available for the logistics of supply and support by intrepid adventurers.

You would think I advocated cooking and eating the other commentators children!

KISS-Organization-Redundancy-Planning, Are the key to success.

May 08, 2018
Nothing that you just wrote has anything to do with you mischaracterizing Clement's statement on habitability, and what other commenters accuse you of is just as irrelevant.

Again: Scientists already acknowledge Mars is uninhabitable today. That does not mean it is necessarily bereft of life, as the presence of life and habitability are two very different phenomenon.

May 09, 2018
I see two choices. A pittance of outrageously expensive, manned expeditions. To cover a few hundred kilometer's of surface. Maybe drill a few hundred meters deep into any surface.

Maybe they will discover Archaic fossils and maybe not. Maybe they will discover living organisms hiding deep under the surface & maybe not.

Heck, a researcher could walk past a clue, by just a meter or two, and miss it entirely.

If there is success claimed at finding fossils or living organism?, How do you confirm & verify the evidence? Send another outrageously expensive expedition. To prove or fail to prove or claiming to disprove the previous results.

Second choice. Concentrate on producing in orbit, fleets of robotic machinery. That could saturate a landscape. Increasing the chances of discovering something important enough to send a human to investigate.

With the robots gathering resources needed to support & expand the human effort.

A systematic effort to cover this System.

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