Real time views of Mars

That reminds me, it recently occurred to me that, because Mars is in a
larger orbit than Earth, the increase in total size of a polar ice cap
coincides with a decrease in the proportion of it visible from Earth, and
vice versa. What is the effect on the total amount of ice cap at each end
visible from Earth?

"AA Institute" wrote in message
oups.com...

Mars Previewer II seems to work just fine, so thanks. The
planetocentric declination of Earth is quoted as -12.2 degrees, that
means Mars' south pole is tilted toward Earth, and the ice cap should
be easily on view in my 8-inch Newt... unless it's summer in the
southern hemisphere of Mars... in which case, the ice cap will be
small. Anyone glimpsed the ice cap yet?

I'm told the summer solstice on Mars has just passed, but was that
summer in the *southern* hemisphere?

Well, actually trying to visualise things in 3D in my head, I just
realised it to be a gemoetrical thing. And you are right about the ice
cap shrinking toward each and every opposition of Mars. During those
times, whichever pole (north or south) is pointed toward Earth, is also
pointed toward the Sun, so the solar radiation incidence on that pole
would be greatest, causing it to shrink to a minimum, depending on the
magnitude of the tilt.
Of course, a lot will also depend on Mars' heliocentric distance at the
time, which varies markedly between oppositions because of the higher
orbital eccentricity.

So, currently, it is midsummer in the southern hemisphere of Mars. For
anyone on vacation there, it'd be time to get the deck chairs out!!!
:-)

Interestingly enough, according to the TES instrument onboard the Mars
Global Surveyor spacecraft, the southern tropics (Martian latitude,
circa. -30 degrees or so) currently experience a daily maximum
temperature of a comfy +20 degrees celsius... can't be bad!

Here's the chart:-
http://tes.asu.edu/daily.html


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On Sun, 04 Sep 2005 13:02:04 -0700, AA Institute wrote:

Lots of options here, from everyone...

Mars Previewer II seems to work just fine, so thanks. The
planetocentric declination of Earth is quoted as -12.2 degrees, that
means Mars' south pole is tilted toward Earth, and the ice cap should
be easily on view in my 8-inch Newt... unless it's summer in the
southern hemisphere of Mars... in which case, the ice cap will be
small. Anyone glimpsed the ice cap yet?

I'm told the summer solstice on Mars has just passed, but was that
summer in the *southern* hemisphere?

I've been doing captures of Mars for the last week. They are he
http://www.bogusnet.net/gallery/view...umName=Mars%21

In some shots, the polar cap is visible, in others it is not.
The pics were taken with a SCT and no diagonal (webcam plugged straight
into the visual back.

If you can ID which meridian is visible in the shots, leave a comment
below the pics. If they are small, click on them and they get bigger.

Where I set up, it seems I just have a little window of decent seeing
when mars gets to a certain altitude. Then thermal effects get in the way
and it gets fuzzier near the meridian.

Oh well. Guess I'm gonna have to take it out into the boonies as
opposition gets closer.

Regards to you all,
Uncle Bob

crappy images.