Hi Jazza, Gary & All
Quote:
Originally Posted by gary
For example, I recollect being at the Wiruna dark sky site around one of the oppositions, probably around the late '90's and the view on that particular night for several hours was better than some of the
closer approaches. The seeing was prefect and it was one of those nights where you could throw more and more power at an object and it just kept delivering. The detail particularly around the icecaps was astounding.
So a very close approach at opposition is opportune, but there can be
the above cited limiting factors, hence a certain amount of luck is involved
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Jazza,
Most are familiar with the Mars-hoax emails that seem to go around nearly every year around August. That email basically says that Mars will look about as big as the full moon on a certain date. Like most hoaxes, rather than being an outright un-truth it is in fact a corruption of the truth (or part thereof).
Back in 2003 (as it will be in 2018 for all intents and purposes) if you view Mars
with a telescope that magnifies about x70, then the image of Mars it produces will be
the same apparent size as the Full Moon as seen with the naked eye.
How do we work that out? The Moon in our sky appears about 30 arc minutes or 1800 arc-seconds diameter. Mars in 2003 was 25.1 arc-seconds diameter. That means Mars appeared 1800/25 = 72 times smaller than the Moon to the naked eye. If a telescope is used to view at x72, it makes Mars look 72 times bigger -- the same
apparent size as the Moon to the naked eye. If you use x144, twice as big, x288 4-times as big etc etc.
Obviously the seeing is the limiting factor then, and to paraphrase what Gary wrote, a smaller-sized but good (seeing-wise) Mars will beat a bigger-sized, bad (seeing-wise) Mars -- every day of the week.
Trouble is, the seeing won't always (rarely in fact, at least in Sydney) co-operate. Further complicating things, the detail on Mars, apart from the polar caps is quite low-contrast in nature meaning the dark bits aren't a lot darker than the light bits.
The detail on Mars is much harder to pick-out than naked-eye detail on the Moon -- it is
subtle and it takes
practice to see. The easiest dark detail to see is Syrtis Major. The polar caps a re generally fairly easy to see and several of the other dark markings too. In good seeing more aperture means more detail.
Don't wait till 2018. There are several okay, if not good opportunities (particularly 2014 & 16) in between to have a lash at it and if nothing else get some practice at training your eyes to see as much detail as the 'scope will show on Mars -- remember a good little Mars will always beat a big bad Mars!
This page here might help a bit too:
http://astronomy.concreteairship.com...marsseeing.htm
Gary,
I remember seeing Mars like that too and I think it was at the 1999 Mudgee Star Party (Sutherland Astronomical Society Inc only) that would almost certainly have co-incided with the ASNSW observing weekend at Wiruna in April 1999. The first night we were there (which according to my observing log would have been Wed 14 April 1999) the seeing was simply stunning. It was up there with the best few seeing nights I've ever seen plus it was only 10 days pre-opposition for Mars giving a 15.4 arc-second diameter disc. The 15th was also very, very good if not as good at the 14th. This was the same year Steve Lee discovered (and I am told Lachlan missed) his comet at the Mudgee Star Party.
In my old 10" I was looking at Mars at x290, x363 and even x580 and it was without a quiver, even at x580 for sometimes minutes at a time. It was the best Mars viewing I can remember period!
Best,
Les D
cool so i have untill 2018 to upgrade my astro gear and learn how to do astro imaging 
you look fit enough to see in another Thirty years at least and 2018 is only nine years away
