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What are reasonable expectations of a 4" apo on mars this year's opposition?

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#1 mike bacanin

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Posted 07 March 2020 - 12:00 PM

I'm looking forward to the Mars opposition later this year. I've put together a nice 100ED setup on a driven equatorial and recently acquired a small set of eyepieces suited to planetary observing including 5XW, 4 TOE and 3.4 HR.

What can I expect to see feature wise in steady seeing? for example can Olympus mons be glimpsed? Mars is one planet I have not really observed in earnest. I'll acquire a map of mars before then. Look forward to your comments.

 

Mike


Edited by mike bacanin, 07 March 2020 - 12:01 PM.

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#2 junomike

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Posted 07 March 2020 - 12:11 PM

Olympus Mons?   Ah, IME using a 6" and 7" ED Refractor, the best I've done is the darker Mare areas and the Polar cap.

 

This is under very steady seeing which I've had maybe 3 - 4 times in 10 yrs.

 

Here's what I'd say is an appropriate representation of what you can expect.

 

Not to be a killjoy, but Mars  IME is  one  of the most disappointing Planets to view (compared to say Jupiter or even Saturn)


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#3 Cliff C

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Posted 07 March 2020 - 12:28 PM

Mike,

You can get very nice views of Mars with a 4" scope on nights of steady seeing. This year Mars reaches opposition in October meaning that it will be at very good height above the horizon where the air is more stable. Mars will also be quite large this time. Some of my best views of Mars were during an autumn opposition back in 2005. The scope I used was a 4" triplet using magnifications between 160x-180x, occasinally up to 200x.

I don't think you come anywhere near resolving Olympus Mons however. That's a task for a much larger scope. After this year the next several oppositions will be during the colder months with Mars not reaching nearly the same apparent diameter.

Get out there and have fun!

Cliff


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#4 dusty99

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Posted 07 March 2020 - 12:33 PM

That's a good question.  I've heard of people making out Olympus Mons as a contrast spot with a C14, and there are pictures where you can see it that were made with a C8 on AstroBin, but those are the result of a combination of a lot of frames captured through different filters.  It seems like a very small target for a 4", even at close opposition.


Edited by dusty99, 07 March 2020 - 12:35 PM.

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#5 Stellar1

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Posted 07 March 2020 - 12:50 PM

I can’t wait to hit up Mars this fall with my new (to me) Eon 115 triplet, better than Christmas!


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#6 sg6

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Posted 07 March 2020 - 12:53 PM

I suspect that you will get a small disk but with shadowy detail.

Might have darker areas and maybe a hint of white at the poles.

 

Mars needs from assorted reading at least 250x and preferably 300x and 350x. It tends to get ignored or not appreciated that Mars at it nearest and bigest (25.1") will always be smaller then Jupiter at it's furthest and smallest (29.8").

 

I tend to agree with Junomike, Mars is disappointing, not a lot to see. Sort of red and a few indistinct darker patches, with maybe a hint of a white pole.

 

And for some reason everyone goes on about it.

At least this year Mars is at the end of the year so more dark time for people.

 

Think 200x will be a red disk with other patches, but will the scope manage up around the 250x mark?


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#7 Hesiod

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Posted 07 March 2020 - 01:05 PM

It goes without saying that more the aperture, more you can see, but even with a 4" you may see a lot, both in term of transient phenomena (e.g. clouds*, thawing, sandstorms,etc...) and "static" features (darker and brighter areas, or the mottled aspects believed by Schiaparelli to be channels**).

Since you have a driven mount, observing at length should not be an issue, and IME this is the most useful thing you can do with your current equipment

 

 

 

 

*these little but bright white dots sometimes mark the position of mt Olympus, in my experience is as close as you can go about "seeing" it in a 4"

 

**actually in some cases may be indeed actual features


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#8 Dave Mitsky

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Posted 07 March 2020 - 01:12 PM

I own a 101mm Tele Vue apochromatic refractor and find planetary views through it rather lacking.  

 

I've observed Mars through larger apertures but most of my views of the Red Planet have been through a 17" f/15 classical Cassegrain at magnifications over 200x.  When the seeing is very good, I use 300x plus.  I use blue, orange, or magenta color filters.


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#9 WarmWeatherGuy

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Posted 07 March 2020 - 01:16 PM

This will give you an idea of what you can capture using lucky imaging. It is way better than what you see with your eyes.

Small bore challenge: Mars w/ 6" or less


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#10 Shorty Barlow

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Posted 07 March 2020 - 01:36 PM

I'm also looking forward to viewing the opposition with my 102mm Starwave. I can set this up fairly easily and might be an interesting alternative to my 150mm Newtonian.

 

med_gallery_249298_10284_129561.jpg

 

Regardless of what the pessimists and 'nay-sayers' claim Mars can be an interesting target in refractors around 10 centimetres. 

 

med_gallery_249298_5348_73571.jpg

 

With the caveat that you don't expect that much of course. I find filters are a great help and I've used all of the above with some success. Larger albedo features such as the Syrtis Major Planum should be visible through a decent 4" refractor. This was first discovered by Christiaan Huygens possibly in 1659 and was the first documented surface feature of another planet. When visible the polar caps can be seen, often with the aid of a light blue filter for some reason. A refractor around 10cm should be able to achieve a good 200x ~ 240x depending on conditions. I've always enjoyed the Mars oppositions. Just don't expect too much.


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#11 Sketcher

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Posted 07 March 2020 - 02:13 PM

As with any other celestial object, I would suggest an approach that involves no expectations.

 

Go out, make observations, take notes, make sketches; and do as so many other telescopic observers have done for the past few centuries:   See what you can see.  And be happy with all that you can see..

 

It's not surprising to hear from owners of larger telescopes saying that you're not likely to see much with a 4-inch apochromat.  Similar statements get made almost daily.  "Seeing a lot" or "seeing a little" are such subjective terms.  Even if one only uses smaller telescopes, one will, sooner or later, end up "seeing a lot".

 

A Mars story:

 

Some time back in the late '60s I made my first Mars observations.  Before that I had read books on amateur astronomy, books that recommended making sketches (among other things).  So I already know quite a bit about observational amateur astronomy before I got lucky enough to receive my first telescope -- a 2.6-inch refractor.

 

I was a bit more fortunate than some of today's beginners.  I didn't have others flaunting their larger apertures and telling me I wouldn't be able to see much.  So I went out on every clear opportunity, observing and sketching Mars with my 2.6-inch (not an apochromat), cardboard-tubed refractor   Over time, my sketches revealed the rotation of Mars.  You see, Mars rotates with close to the same diurnal period as earth.  As a result, when one observes the planet at the same time, on consecutive nights, one ends up seeing (very nearly) the same earth-facing hemisphere of Mars.  Yet, over time, the rotation difference takes its toll, and ever so gradually, as days become weeks, one sees those features move with the planet's rotation.  Eventually, I found myself changing my observing times to catch the planet as early as possible or as late as possible in order to see just that tiny amount beyond one Martian limb or the other.

 

Did those sketches show much?  Well, they showed enough -- enough to keep me going out on every clear opportunity, enough for me to see and identify the most prominent Martian surface features, enough to watch as the planet slowly rotated about its rotational axis.

 

I have fond memories of those days, and those (long lost) sketches.  But if someone had informed me that I wouldn't be able to see much with a 2.6-inch telescope, would I have made those observations?  Would I have those memories?  Would I have stuck with amateur astronomy for the next five decades?  Yeah, I was "hooked" even before looking through that first telescope.  But I started out in a different time, and as Jon might say:  I lived (and evidently still live) in a different world.

 

So just go out and make your observations.  Don't give any thought to what others see or claim to see.  All that really matters is what you see -- regardless of how little or how much that might be.


Edited by Sketcher, 07 March 2020 - 02:15 PM.

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#12 Rutilus

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Posted 07 March 2020 - 02:23 PM

I made this Mars map from an opposition several years ago. The scope used  was a 120mm f/8.3 Achromat.

Regarding Olympus mons,I have seen white clouds around the feature that have given its position away,

that observation was made with a 100mm ED scope.

If there are no dust storms, your scope is capable of picking out many features.

 

Attached Thumbnails

  • Mars-mapcn.jpg

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#13 MarkGregory

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Posted 07 March 2020 - 02:57 PM

Don’t be disappointed when you realize you won’t see details on the Mars surface, it is simply way too far away for terrestrial telescopes to pick up surface features. JunoMike showed you in his attached image what you might see, if you are lucky. And, if there is a dust storm on the planet, you won’t see anything. Or I should say “we” won’t see anything. Good luck and have fun. 


Edited by MarkGregory, 07 March 2020 - 02:59 PM.


#14 Astrojensen

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Posted 07 March 2020 - 03:17 PM

 it is simply way too far away for terrestrial telescopes to pick up surface features.

What nonsense is this? 

 

Earth-based amateur telescopes can absolutely show surface features on Mars. 

 

 

Clear skies!
Thomas, Denmark


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#15 mikeDnight

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Posted 07 March 2020 - 03:34 PM

Mike, you'll be able to see loads of detail on Mars in your 4" ED. If you make sketches, you'll see the planet rotating, and be able to get a real feel for the features on view. Olympus Mons is well within the grasp of your telescope. Sometimes it will appear as a bright spot due to cloud, while at other times it may be cloudless and appear as a dark spot.

 

Attached are a couple of maps of Mars that I've made. The first was in 2003 as viewed through a 5" apo at 149X, while the second map, made in 2016, is much more meaningful to you, as it was made using a 4" apo while Mars was only a few degrees above the UK horizon. Mars in 2020 will be much higher and much larger than in 2016, so even greater potential to get detailed views.

 

IMG_5291.jpg

 

583f5cfdf1d05_2016-11-2814_16_39.jpg.030c1cb6f11b988d7a8ecc8e2d768263.jpg

 

I forgot to mention, the top map was made from observations looking directly through the telescope, without a diagonal.

The bottom map was made from observations using a prism diagonal, so north is top with east west reversed. I purposefully made it this way so I could use it as a reference while looking through my diagonal during future apparitions. It's all about comfort for me these days!


Edited by mikeDnight, 07 March 2020 - 04:06 PM.

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#16 mikeDnight

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Posted 07 March 2020 - 03:54 PM

Below are some of the original sketches from my 2016 observations while using my 4". The scope was almost horizontal because of the low angle of the planet, yet there was never a time when detail wasn't visible.  The sketches are imaged off my tablet as the original pic's are too large to post, so I apologise for the low quality, but it may give some idea of what things may look like. With Mars being much higher and larger in 2020, I'm hoping that detail will be even more obvious.

 

IMG_5358.jpg


Edited by mikeDnight, 07 March 2020 - 03:57 PM.

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#17 dusty99

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Posted 07 March 2020 - 03:56 PM

I like those drawings, MikeD!  Last opposition I saw some good surface detail in both a 5" achro and a 4" apo, just nothing as small as Olympus Mons.  A regular yellow #8 filter helped.  You may have better seeing, as I'm on a mountainside.


Edited by dusty99, 07 March 2020 - 04:00 PM.

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#18 t.r.

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Posted 07 March 2020 - 04:19 PM

What nonsense is this?

Earth-based amateur telescopes can absolutely show surface features on Mars.


Clear skies!
Thomas, Denmark

Thank you some sanity at last!!! Folks details on Mars at opposition can be seen in a 60mm refractor for cripes sake! 100mm will do fine for this apparition rest assured. Look up Ron Bee’s “Light Cup Journals” and Bill Palino’s Mars sketches for what is possible with 4 inches...yes Olympus Mons as an albeido feature (not resolvable) is doable as is the “w” clouds...I’ve done it with a TV Genesis! Such bunk here...really discouraging for someone looking for facts. You’re observing location means a lot!

Edited by t.r., 07 March 2020 - 04:24 PM.

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#19 sunnyday

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Posted 07 March 2020 - 05:04 PM

I'm also looking forward to viewing the opposition with my 102mm Starwave. I can set this up fairly easily and might be an interesting alternative to my 150mm Newtonian.

 

 

 

 

With the caveat that you don't expect that much of course. I find filters are a great help and I've used all of the above with some success. Larger albedo features such as the Syrtis Major Planum should be visible through a decent 4" refractor. This was first discovered by Christiaan Huygens possibly in 1659 and was the first documented surface feature of another planet. When visible the polar caps can be seen, often with the aid of a light blue filter for some reason. A refractor around 10cm should be able to achieve a good 200x ~ 240x depending on conditions. I've always enjoyed the Mars oppositions. Just don't expect too much.

I love it when we give a description like yours. thank you


Edited by sunnyday, 07 March 2020 - 05:08 PM.

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#20 sunnyday

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Posted 07 March 2020 - 05:07 PM

Sketcher,

thank you for sharing your memories, really interesting.



#21 Shorty Barlow

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Posted 07 March 2020 - 06:18 PM

I love it when we give a description like yours. thank you

You're welcome.



#22 John Miele

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Posted 07 March 2020 - 08:28 PM

I was able to see polar ice and some dark markings in my SV90T when Mars was only around 10 arc-sec dia. In a 100mm at the peak of this opposition, I expect you will see many surface details on a night of good seeing. Try red and orange filters and remember it takes patience. If you want to really see Mars, park yourself in a comfortable observing chair and allow at least an hour. It's amazing how the details begin to appear...


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#23 jeffmac

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Posted 07 March 2020 - 09:47 PM

It's mostly about the seeing. With superb seeing and your set-up, you should be able to see substantial detail. My experience on Mars with my Tak FC100 has shown me excellent detail, when the seeing is excellent. Polar cap with detail around the edges, the Hellas basin, the major dark "continental" features and limb clouds are some features that are visible with a 4" apo. Very satisfying for me. YMMV.

Edited by jeffmac, 07 March 2020 - 09:55 PM.

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#24 John Fitzgerald

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Posted 07 March 2020 - 09:58 PM

Mars is always a disappointment to me over 50 plus years, even with favorable oppositions, which occur with Mars fairly far south of the equator, unfavorable for my location.  When nearest, the disk is still small, but very bright.  When it gets high in the sky here, it is in an unfavorable opposition.  The last few oppos, I have just ignored it.



#25 gene 4181

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Posted 07 March 2020 - 10:15 PM

 And start  viewing Mars as soon as possible  ,  the more you view  it  the more you'll start too see  .   I've always enjoyed Mars  , its a favorite  .


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