Through Your Telescope: Mars

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Sun, Dec 30 - 5:32 pm EST | 10 years ago by
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    Now is an excellent time to view Mars. If you just got a new telescope for Christmas, you’ll be able to get excellent views of Mars throughout January.

    Here’s where it is (click on it to see a bigger one):

    Marsevening
    Mars is visible over the eastern horizon in the early evening.

    Most telescopes will show you a nice, bright red disk and sometimes you can see white dots, the polar ice caps, at either the top or bottom.

    OK, so I was disappointed in Stellarium for this little demo. The images below aren’t quite representative of what you’ll see. For example, Mars looks bigger in an AstroScan than in the LX200. That’s because Stellarium switched rendering modes and started showing a Hubble image when the FOV got small.

    Still, you can sometimes see the moons of Mars through a 10 inch SCT, so that was accurate.

    Here’s a general idea of what you’d see through an Astroscan:

    Marsastroscan-1
    Take this one with a grain of salt. Mars doesn’t look this big in an Astroscan. You can see a bright red disk though and sometimes the polar caps.

    Here’s Mars through an 8-inch Dobsonian:

    Marsdobsonian
    With an 8-inch Dobsonian, polar caps are sometimes visible on really steady and clear nights.

    Finally, the LX200:

    Marslx200
    Mars is excellent through a 10-inch SCT, like the LX200. I often see dark regions marking the surface on clear, still nights. I never thought they were canals, though.

    It used to be that refractors offered better views of the planets because of their long focal lengths, optics free of aberrations typical in mirror telescopes and higher magnifications. Over the years, the optics in reflecting telescopes has gotten so much better that I now think they do every bit as good on the planets as a refractor.

    Congrats on your new scope, now get out there and start using it!

    Next up: The Andromeda Galaxy. It’s heading right for us you know…

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      • http://www.gpsreview.net/ Tim

        I’ve noticed that you appear to be using Stellarium to approximate what Mars might look like, or what level of detail you might see on Mars, by somehow correlating different telescope configurations with Stellarium settings. Can you explain how you did this?

        As one of those “new telescope for Christmas” people, I’m trying to approximate not only what my viewing expectations should be, but also what the “best case scenario” might offer.

        How might I use Stellarium to approximate the level of detail I might see with the various configurations on my own scope? What do I need to know about my scope and how to I correspond that to settings in Stellarium?

        I understand what Stellarium will show is a “best case” scenario and that due to light pollution and atmospheric junk I will probably never match the “best case” view, but it would help me set expectations and know how close I am to actually using the scope properly. :)

      • http://www.astronomybuff.com Tony

        Hi Tim,

        Yes, well…. as I mentioned in the post, Stellarium didn’t do all that great of a job approximating what you’d see in an eyepiece. As I zoomed it, the rendering mode changed to that of a HST image of Mars, which you’re definitely NOT going to see through your eyepiece.

        On most nights, you can expect to see a fuzzy red dot. On some exceptionally clear nights, you’ll see little white spots on the top or bottom of the dot, those are the polar ice caps.

        On extraordinarily clear nights (your best case scenario), you can see the polar caps, bright and dark regions from the mare and perhaps a follow a dust storm (but that usually corresponds to a lack of contrast and it isn’t all that exciting to look at).

        To see much detail, you’ll need higher magnification, between 100-250x and a very clear, still night. This means a really steady mount, decent optics and large aperture. You’ll also need to spend more time that you want getting a good focus.

        Usually, the atmosphere will limit what detail you can see though.

        Hope this helps and let me know how it goes…

      • http://www.gpsreview.net/ Tim

        Thanks, Tony! Perhaps maybe I should ask it a little differently. Ignoring Mars for a moment, (sorry Mars) the way you have labeled some of the Stellarium screenshots “through an 8-inch Dobsonian” and “through a 10-inch SCT” seems to hint that you are taking some sort of values from the telescope and corresponding them to values in Stellarium. Ignoring that Stellarium didn’t do a good approximation of what it would actually look like, how might I take some of the specifications from my scope and “match” them with some sort of Stellarium settings to compare “this is what I see through my scope” versus what Stellarium shows.

        Is there some way to take some values from the telescope like the scope focal length and the eyepiece focal length (just guessing those might be the appropriate units, I’m probably wrong) and then “matching” that in Stellarium to try to simulate the same view? (Albeit inaccurate as you mention.)

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