Planet Four Talk

Obliquity of Mars

  • HMB6EQUJ5 by HMB6EQUJ5

    To what extent does the Martian Olbiquity play in understanding the formations we are currently viewing? To my knowledge Mars' obliquity is rather close to Earth's at this time (roughly Mars: 25degrees Earth: 23degrees). However long term (the aspect I'm more interested) due to gravitational pull from other planets, Mars can tilt anywhere from lower than 10 degrees to perhaps over 60 degrees!. Resulting in longer winters and shorter summers at times. Ergo, the current South Polar region would have been in a more "temperate" climate and areas of currently higher latitude would have been in permafrost i would imagine. There's a nice short article about this on the HiRISE page written by Edwin Kite.

    Additionally I would be interested to know if it is envisioned at some point "down the road" to expand P4 research to more higher latitudes?

    The discussion board has been very dynamic and the subj of "Boulders" has been a wonderful read. Many thanks in advance...

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  • Kitharode by Kitharode moderator

    Hi Bill. Tricky question. You're right when you say that Mars' obliquity varies greatly over time, so it seems obvious that major changes will occur on the surface. Exactly what those changes would be and what effect they would have I'm not sure about, but I'll come back as and when I find anything. I'm sure others will have something to add.

    Obliquity won't affect the length of winter/summer, that's controlled more by the eccentricity of the orbit. Mars has a relatively large eccentricity and is closest to the Sun, hence moving at its fastest, in southern summer. This is why the current southern summers are relatively short and hot.

    I'll let Meg talk about the future of P4. We're certainly going to the north pole in the future.

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  • HMB6EQUJ5 by HMB6EQUJ5 in response to Kitharode's comment.

    Correct Kith..! Possibly higher temps in summer and lower temps in winter but length is not a consequence. 😃

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  • Kitharode by Kitharode moderator in response to HMB6EQUJ5's comment.

    Not knowing how much you know about astronomy, forgive me if I'm feeding you stuff you already know. This discussion doesn't answer your original question, but it's very relevant and hopefully useful: http://talk.planetfour.org/#/boards/BPF0000008/discussions/DPF0000ddz

    In short, changing the tilt of a planet changes the latitudes at which 'permanant' day/night will occur. On Mars this will have an effect on where the seasonal icelayer will form.

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  • HMB6EQUJ5 by HMB6EQUJ5 in response to Kitharode's comment.

    thanks again for that discussion link is interesting and the article from NASA AMES adds to my understanding here 😃 . I'll have to journey sometime "over the hill" from the coast and visit NASA AMES.

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  • mschwamb by mschwamb scientist, translator in response to HMB6EQUJ5's comment.

    Additionally I would be interested to know if it is envisioned at some point "down the road" to expand P4 research to more higher latitudes?

    Spiders seem to restricted to the South Pole. There are also some fans discovered on dunes in the North so we do eventually plan to head to the North Pole of Mars. So we do plan to eventually head to the North has Kith said. In terms of other latitudes, it would be a different project, but there was talk a long while ago that when we're done with the South and North Pole of doing something else like looking for changing features by having citizen scientists review images of the same spot at different times. That's just brainstorming. We've got lots of images from HiRISE to go through, no shortage of things to look at right now, but in 2-5 years we could be doing incorporating new things.

    Cheers,

    ~Meg

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  • HMB6EQUJ5 by HMB6EQUJ5 in response to mschwamb's comment.

    Greatly appreciated Meg! Thx 4 reply with your busy schedule.

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  • mschwamb by mschwamb scientist, translator in response to HMB6EQUJ5's comment.

    No problem. I'm slightly less busy now that the conference is done. To give more of an answer, the obliquity basically would change the location of the Polar cap such that as you said what is now the polar layered deposits would not be ice covered. I believe the obliquity changes are thought to have impacted the formation of the layers in the South Polar Layered deposits (see this), but as long as there is an ice sheet of carbon dioxide ice exposed the geysers would still go off likely. off since the Southern Summer would still happen during perihelion. Though this hasn't been explicitly modeled. I think you'd need to assume alot about the properties of the geysers. Hopefully with Planet Four we'll learn more about how the geysers go off and spiders form.

    Cheers,

    ~Meg

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