ART ASTRONOMY Uranus
2023 on Sun, Moon, Venus & Miscellaneous PROCESSING
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MARS
2010, 2012 & 2014 Mars is the planet we most associate with possible extra-terrestrial life in our Solar System. (even if this isn't necessarily true!) The "Red Planet" has been the subject of science fiction for many years & the similarities between Earth & this (smaller) world are some of the reasons behind that thinking... The rotational
period of Mars is roughly the same as Earth's (roughly 24 hours 40 minutes)
& like our Earth the tilt of Mars creates seasons (though more extreme
than here on Earth) with the polar regions being covered in icy caps during
the winter seasons. These icy caps which expand & shrink as the seasons
on Mars change, are made up of frozen water with a thin layer of "dry
ice" (frozen CO2) on top...it has been suggested that if the entire
South Polar region were to melt it would cover Mars entirely with water to a
depth of about 36 feet! |
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All the Mars images here have been taken with the planet not in the most favourable position in our skies – the elevation is getting better each apparition & by the next in 2016 Mars should be nice & high for us, making it much better for imaging! J Compared next to each other Mars is roughly half the size of our Earth...its gravity around 37% of ours - which suggests anyone could leap almost 3x the height they could on Earth! :) The Sun is much further away from Mars (over 1.5x further than from Earth) & from that distance the Sun appears around half the size of what it does in our skies...warming the Red Planet substantially less than it does us..! Mars has 2 tiny moons that race across the Martian sky constantly - Phobos & Demos... (Fear & Panic - appropriate as "Mars" was a god of war!) Phobos races across the Martian sky twice a day, Demos is much slower but still only takes less than 3 days to cross the Martian sky! |
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Mars has clouds & dust storms
(some of these are gigantic, lasting weeks) as well as volcanoes - seemingly
extinct but scientists are not entirely certain of that... Some of these
volcanic mountains are literally enormous - Olympus Mons is 3x taller than There are also huge chasms or valleys/canyons & the Mars Lander craft reveal stony landscapes on the surface, not unlike many places on Earth. But Mars possesses only a thin
atmosphere & temperatures are much colder in general than on Earth, with
large fluctuations also... |
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This image was taken well into the 2014 Martian apparition. (an apparition is when Mars first appears in the morning sky after coming out from behind the Sun as viewed from the Earth, till when it disappears behind the Sun in the evening sky...) At 9.8 arc-seconds in diameter (our Moon appears at 1800 arc-seconds in our sky in comparison!) the Red Planet was becoming fairly small again after opposition but there is still plenty to see, with thin cloud covering much of the right-hand side in this image...this is the side that is shadowed in darkness because Mars like our Moon also goes through phases. You can also see on the upper right 3 darker "spots" - these are 3 large volcanoes, the Tharsis trio with their peaks poking out above those thin clouds! Slightly to the left of the lower one of these volcanoes is an eye-like feature, this is actually a dust storm over "Solus Lacus." The icy North pole appears at the bottom as that white patch... |
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The next
image is looking at a different side of Mars, clouds are still visible as is
the North Polar cap. (NPC) |
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Another perspective, in this we see "Syrtis Major" - that dark feature/form that resembles the Indian sub-continent here on Earth. Both the white NPC & South Polar regions are on display in this image, white haze covering the SP regions: this is where the “Hellas Basin” is - a huge, impact crater, the largest one visible in our Solar System. At about
2300km across & 9km deep scientists speculate as to whether liquid water
might exist at the bottom due to the atmospheric pressure being so much
greater than that on the general surface of Mars where the pressure isn’t
sufficient to allow this liquid state, turning ice into water vapour. Again in this image there are thin clouds across much of
the Martian globe. |
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Very similar to the preceding image but with slightly less evidence of cloud cover in this image...these last 3 images were taken when Mars was appreciably larger than in the first image (roughly 13 arc-seconds for these 3) |
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Again similar but with Syrtis Major much nearer the left hand side (or "Limb") Seen in the perspective shown in my image here Mars is rotating from right to left with the North Pole at the bottom. In technical terms the left limb is known as the "P" limb & the right limb the "F" - this designates that the left "P" is "preceding" or "going first" so it is on the side that Mars direction of rotation is heading...the "F" meaning "following" & this is the trailing side of Mars..! If the image
was displayed with the North Pole at the top of the image
then everything would be transversed…with the planet appearing to rotate from
left to right! J |
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Mars is 14.4 arc-seconds (written as 14.4") in this image (almost as large as it got in the 2014 opposition) We can see the cloud cover in general but also more concentrated little patches of cloud - those on the lower left not amongst the general cloud cover on the upper right. We also see 2 of the Tharsis volcanoes poking through the cloud cover on the upper right: the large "square-like" dark feature in the lower half is called "Acidalia Planitia." |
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Here on a night with good seeing we see Olympus Mons almost at centre-stage on the planet. (actually a bit to the right & up from dead-centre!) We can see that the NPC has receded at the bottom of the planet leaving little patches of icy areas surrounding it. Olympus Mons is the largest shield volcano known as described at the start of the Mars section here...I have used a NASA image in the insert & placed our image next to it in this little insert above the planet...NASA image on the left. In our own image the lighter "reverse C" is the edge of the volcanic escarpment, some 600km across. This is where it rises from the plains below reaching that aforementioned height of (roughly) 25km at the top where the "caldera" is situated, the centre of the dark spot in our image: this is the depression at the top of most volcanoes where they discharge most of their larva etc... (Click this image for full scale.) |
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The next image set is the individual channels from the preceding image with the combined rgb (colour) image shown below these channels: this is the size we saw on the screen of our laptop as we captured the videos. The blue
channel shows the clouds to best effect & the red the dark
markings...these dark markings change over time because the winds on Mars
drive the predominantly red soil/sand around the Martian globe depositing it
on the darker areas & in effect hiding some of this dark material to
different degrees over time...hence their apparent changes in appearance. (Click this image for full scale.) |
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Another vista of Mars, this time with bright clouds in the centre of the disk: this is actually Elysium Mons. Another
"monster Martian volcano" wreathed in "orthographic
clouds" which is the term for clouds that gather around mountains that
are very high. (similarly on Earth) This image was taken 3 nights after the
next 3 images... |
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The next
image is another where Syrtis Major is on the "CM" or "central
meridian" - that longitudinal coordinates
system used on all planets similar to those used on Earth in many respects...
this & the next 2 images were
taken on the same night. |
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This time Syrtis Major is
further to the left or closer to the "F" limb. (see above) This
means that Mars had not rotated as much as in the image above...in fact this
image was taken 100 minutes earlier than the previous image on the same night
giving us a clear idea of the direction & rate of rotation! ;) |
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...almost 2 hours earlier again on the same night with Syrtis Major having only just come around the "F" limb/edge: in this & the 2 images above we can also see Elysium Mons wreathed in those "orographic clouds" mentioned in the image taken 3 nights later. Another
interesting point is that the clouds over Syrtis Major here are distinctly
"blue" - they are known as "Blue Syrtis Clouds" &
have been a recognised phenomenon on Mars for many years. |
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The next image is one with
Syrtis major & its "Blue Clouds" disappearing around the
"P" limb..! |
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Another night with very good seeing, here Olympus Mons is shown to the right ("F" Limb) side of the centre of Mars' disk. Some of those
darker markings amongst the cloud features to the left & slightly above
Olympus Mons (adjacent to the Tharsis volcanoes) is the Valles Marineris canyon system - 4000km long with depths of up to 7km..! |
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Another vista with Olympus
Mons, Valles Marineris & the Tharsis volcanoes around
the central regions of this image... |
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This time
(just for something different!;) ) a view showing
Syrtis Major but with Mars the other way up...ie,
with the North Pole at the top of the image. J |
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Another slightly different view
with one of the Tharsis volcanoes peeping through the clouds at the upper
right... |
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Yes - you guessed it, another image revealing a similar face of Mars! Seeing dictates that you get images of Mars when the seeing cooperates, not necessarily when the face of Mars you'd like to image is showing..! ;) But here the
image reveals some of those very nice little "puffy" clouds as well
as the more extensive, thin, hazy cover. |
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We're winding back 2 years here to the 2012 apparition. (Mars is only favourably placed for imaging every 2 years). Mars was even lower in elevation in the
skies for the 2012 apparition & harder again to get good images, but for
these few images we were quite fortunate! The Acidalia
Planitia region is well displayed as is the NPC - notice the large
"rift" or "chasm" in this Polar Cap. (Chasma Boreale) |
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Another
view of the polar ice canyon (Chasma Boreale) in
this image...this chasm is almost 600km long, about 100km wide & up to
2km deep..! |
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A rather hazy image here with Syrtis Major prominent again! Elysium Mons
with its orographic clouds is disappearing around the left "P"
limb/side. |
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In this
image there is a small amount of haze (orographic clouds) around Elysium Mons
in the centre of the Martian disk with Syrtis Major only just coming into
view on the "F" limb, accompanied by its (almost) trademark blue
cloud cover... |
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Now a simple animation composed of several frames put together to create this rotating Mars: it is an image using the blue filter (ie, a "mono" image) & this filter is best at revealing the clouds that are usually a feature on the Red Planet. Because this
image is "upside down" in comparison to most of the other images
with the NPC at the top it appears to rotate the opposite as I explained
above...but this is all just to do with whichever way we orientate the
globe!!! :) Several concentrated little cloud "clumps" feature in
this blue image animation. |
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Here
is an image taken with a smaller scope & a (now) very old model colour
camera. (colour cameras record in full colour) Mars was only 34 degrees above the Northern horizon (very low for
imaging) & we were very inexperienced at the time…but for all its faults
this image was still fairly nice..!;) |
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