Depictions of planetary atmospheres in art

For a long time before probes landed there, the favourite colour
depicted in art for the atmosphere of the planet Mars was blue.

Chesley Bonestell depicted stark Martian landscapes with a deep blue
sky. When Viking landed, one of the first colour images displayed was so
skewed in its chroma histograms, the rocks (and the sky) were blue.
Whether this was deliberately done by an overzealous Bonestell fan or
simply out of a silly mistake (which was rapidly rectified), I can't
say, but Mars, up to when probes landed on it, had a blue sky in the
minds of humans.

Sky colour is determined by the chemical makeup of the atmosphere, but
Mars' colour is less to do with its gases and more to do with its dust.
Hubble telescopic observations suggest that at some points Mars'
atmosphere is indeed blue, but I'm wondering what an observer on the
surface might see even at those points in time.

I've also seen depictions of Jupiter from amidst the cloudtops -
beautiful paintings by Adolf Schaller, Alan Gutierrez and Andrew C
Stewart for example. They invariably depict the deep sky above the
clouds being a deep blue. Now, somewhere there must be a technical paper
or something that leads to this invariability, but I must ask: Galileo's
images of Jupiter, looking at the limb and the cloudtop haze, in true
colour, suggests that there is little there to support Jupiter's sky -
to an observer amidst the cloudtops - being blue as such.

Earth's skyglow - the haze that bleeds off into space above the solid
surface visible to any astronaut or aviator flying high enough - is a
deep blue. Earth's sky from the perspective of an observer on the
surface is blue. Mars' skyglow - as tenuous as it is - tends to be a
biscuit brown to orange colour. Mars' sky - according to probes that
have landed there - is a biscuit brown at the horizon tending to a
coffee at the zenith, with an odd blue haze directly around the sun.
Based on photographs from Voyager and Galileo, the best I can come up is
that Jupiter's sky at those high altitudes would be a quite subtle
greyish orange-brown, that a more technically correct backdrop to a
depiction of - say - the Galileo parachute probe would be a quite subtle
greyish orange-brown.

Thoughts?


David
--
per aspera ad astra

In article , wrote:


I've also seen depictions of Jupiter from amidst the cloudtops -
beautiful paintings by Adolf Schaller, Alan Gutierrez and Andrew C
Stewart for example. They invariably depict the deep sky above the
clouds being a deep blue. Now, somewhere there must be a technical paper
or something that leads to this invariability, but I must ask: Galileo's
images of Jupiter, looking at the limb and the cloudtop haze, in true
colour, suggests that there is little there to support Jupiter's sky -
to an observer amidst the cloudtops - being blue as such...

Y'know, David, I was starting to think I was the only one here who was
curious to know if the descending Galileo probe was going to be pointed so
that it could get some sky-view shots as it got deeper into the cloud
layers. I was fairly disappointed when I read that it was only going to be
sending data, not images. You ever check the article in Spaceflight Now,
about Galileo's Jovian atmospheric entry, featuring a rather creepy
artist's concept of Galileo hitting atmosphere flaming and falling apart,
a la Columbia, at http://spaceflightnow.com/galileo/03...lileogone.html
....containing the image at
http://spaceflightnow.com/galileo/images/burnup.jpg

You know what _I_ can't wait for is the images from the Huygens lander at
Titan, unless it hits one of those friggin' methane lakes.

So, any bets, anyone, on whether or not the image from the Cassini Web site at
http://saturn.jpl.nasa.gov/cgibin/gs...jpg&type=image
is going to be at all accurate? Something about the way those frozen
methane outcroppings are rendered reminds me too much of the cover art
from an old Hugo Gernsback "Amazing Stories" mag. Even if Huygens misses a
lake, I'm still worried that the sky on Titan is going to be so thick that
you can't really watch Saturn rise over the horizon.

--
"All over, people changing their roles,
along with their overcoats;
if Adolf Hitler flew in today,
they'd send a limousine anyway!" --the clash.
__________________________________________________ _________________
Mike Flugennock, flugennock at sinkers dot org
Mike Flugennock's Mikey'zine, dubya dubya dubya dot sinkers dot org

Mike Flugennock wrote:

In article , wrote:


I've also seen depictions of Jupiter from amidst the cloudtops -
beautiful paintings by Adolf Schaller, Alan Gutierrez and Andrew C
Stewart for example. They invariably depict the deep sky above the
clouds being a deep blue. Now, somewhere there must be a technical paper
or something that leads to this invariability, but I must ask: Galileo's
images of Jupiter, looking at the limb and the cloudtop haze, in true
colour, suggests that there is little there to support Jupiter's sky -
to an observer amidst the cloudtops - being blue as such...

Y'know, David, I was starting to think I was the only one here who was
curious to know if the descending Galileo probe was going to be pointed so
that it could get some sky-view shots as it got deeper into the cloud
layers. I was fairly disappointed when I read that it was only going to be
sending data, not images.

Not enough power and bandwidth for graphics data, I'd imagine. I was sad
the parachuting probe had no imaging capabilities.

You ever check the article in Spaceflight Now,
about Galileo's Jovian atmospheric entry, featuring a rather creepy
artist's concept of Galileo hitting atmosphere flaming and falling apart,
a la Columbia, at http://spaceflightnow.com/galileo/03...lileogone.html
...containing the image at
http://spaceflightnow.com/galileo/images/burnup.jpg

Gee, what do you know - a blue sky... ;-)

You know what _I_ can't wait for is the images from the Huygens lander at
Titan, unless it hits one of those friggin' methane lakes.

So, any bets, anyone, on whether or not the image from the Cassini Web site at
http://saturn.jpl.nasa.gov/cgibin/gs...jpg&type=image
is going to be at all accurate? Something about the way those frozen
methane outcroppings are rendered reminds me too much of the cover art
from an old Hugo Gernsback "Amazing Stories" mag. Even if Huygens misses a
lake, I'm still worried that the sky on Titan is going to be so thick that
you can't really watch Saturn rise over the horizon.

When Voyager went past Titan, the moon was blanketed in a thick layer of
cloud, leaving a lot of people thinking that's all Titan would *ever*
be. No probe has been near Titan since, but not that long ago Hubble was
pointed in that direction. A series of snapshots showed Titan to have
large dark formations, suggesting the possibility Voyager experienced
what Mariner 9 did at Mars - it arrived at an inopportune time
weather-wise. Unlike Mariner, Voyager simply flew past, unable to hang
around and wait for whatever to subside. With HST however, Titan has
been observed with a comparatively clear sky (if the dark patches
observed are not huge meteorological formations - who knows?). Either
way, I'm reasonably hopeful about Titan's skies and Huygens.


David
--
per aspera ad astra

On Tue, 28 Oct 2003 14:52:50 GMT, David Sander
wrote:

Mike Flugennock wrote:

In article , wrote:


I've also seen depictions of Jupiter from amidst the cloudtops -
beautiful paintings by Adolf Schaller, Alan Gutierrez and Andrew C
Stewart for example. They invariably depict the deep sky above the
clouds being a deep blue. Now, somewhere there must be a technical paper
or something that leads to this invariability, but I must ask: Galileo's
images of Jupiter, looking at the limb and the cloudtop haze, in true
colour, suggests that there is little there to support Jupiter's sky -
to an observer amidst the cloudtops - being blue as such...

Y'know, David, I was starting to think I was the only one here who was
curious to know if the descending Galileo probe was going to be pointed so
that it could get some sky-view shots as it got deeper into the cloud
layers. I was fairly disappointed when I read that it was only going to be
sending data, not images.

Not enough power and bandwidth for graphics data, I'd imagine. I was sad
the parachuting probe had no imaging capabilities.


I read an article that mentioned the bandwidth issues when it got in
close to Jupiter and because of all the interferece they were lucky to
get data :-) Now if they could somehow get a SLAM (Project Pluto) to
fly amongst the clouds, and skip the warheads for more shielding and a
longer lasting reactor. . .well it could be interesting.

In article ,
David Sander wrote:
Not enough power and bandwidth for graphics data, I'd imagine. I was sad
the parachuting probe had no imaging capabilities.

There was a proposal to put a camera on the atmosphere probe. Alas, given
the low radio data rate, relatively few pictures could have been returned
even with compression. Moreover, doing image compression with early-1970s
electronics (Galileo was *old*) required unpleasantly large amounts of
hardware and power. So it looked unattractive and didn't get selected.

...I'm still worried that the sky on Titan is going to be so thick that
you can't really watch Saturn rise over the horizon.

When Voyager went past Titan, the moon was blanketed in a thick layer of
cloud, leaving a lot of people thinking that's all Titan would *ever*
be. No probe has been near Titan since, but not that long ago Hubble was
pointed in that direction. A series of snapshots showed Titan to have
large dark formations...

Careful here -- if I'm not mistaken, those Hubble images were in infrared.
It looks like Titan's atmosphere is halfway clear at some IR wavelengths.
Unfortunately, I don't think Cassini has imaging capability in that band
(although I could be wrong, it's been a while since I saw details on it).
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |

Henry Spencer wrote:
In article ,
David Sander wrote:


When Voyager went past Titan, the moon was blanketed in a thick layer of
cloud, leaving a lot of people thinking that's all Titan would *ever*
be. No probe has been near Titan since, but not that long ago Hubble was
pointed in that direction. A series of snapshots showed Titan to have
large dark formations...


Careful here -- if I'm not mistaken, those Hubble images were in infrared.
It looks like Titan's atmosphere is halfway clear at some IR wavelengths.
Unfortunately, I don't think Cassini has imaging capability in that band
(although I could be wrong, it's been a while since I saw details on it).

According to
http://www.lpl.arizona.edu/conferenc...ume/mcewen.pdf
Cassini has "better spectral (and polarization) filters for
imaging the surface than does HST." They also suggest that while the HST
images of the surface may appear clear, there is a possibility that even
in the 'atmospheric window' (940nm) over 99% of the light reflected from
the surface may be transmitted diffusely. If so Cassini won't be able to
make much of an improvement on HST's 100km/pixel.


John Cody

"David Sander" wrote in message
...
For a long time before probes landed there, the favourite colour
depicted in art for the atmosphere of the planet Mars was blue.

Chesley Bonestell depicted stark Martian landscapes with a deep blue
sky. When Viking landed, one of the first colour images displayed was so
skewed in its chroma histograms, the rocks (and the sky) were blue.
Whether this was deliberately done by an overzealous Bonestell fan or
simply out of a silly mistake (which was rapidly rectified), I can't
say, but Mars, up to when probes landed on it, had a blue sky in the
minds of humans.

Bonestell did one painting of Mars with a grey sky under the advice of
Gerard Kuiper of Yerkes Observatory. This painting was published in Life
magazine, but Bonestell worried about the paintings he was just completing
for his book, The Exploration of Mars, all of which had blue skies. He
contacted Earl Slipher, who had just returned from observing and
photographing Mars in South Africa. Slipher assured Bonestell that Mars' sky
would be blue, much to the artist's relief.

Sky colour is determined by the chemical makeup of the atmosphere, but
Mars' colour is less to do with its gases and more to do with its dust.
Hubble telescopic observations suggest that at some points Mars'
atmosphere is indeed blue, but I'm wondering what an observer on the
surface might see even at those points in time.

Bill Hartmann has told me that Mars' sky would be a deep, stratospheric
blue, which would be visible whenever the dust thinned.

I've also seen depictions of Jupiter from amidst the cloudtops -
beautiful paintings by Adolf Schaller, Alan Gutierrez and Andrew C
Stewart for example. They invariably depict the deep sky above the
clouds being a deep blue. Now, somewhere there must be a technical paper
or something that leads to this invariability, but I must ask: Galileo's
images of Jupiter, looking at the limb and the cloudtop haze, in true
colour, suggests that there is little there to support Jupiter's sky -
to an observer amidst the cloudtops - being blue as such.

The blue sky of earth is the result of the size of the oxygen molecule,
which scatters the light hitting it ("Rayleigh scattering"). I should think
that any gas molecules of about the right size would do the same thing.
Gasses which are themselves colored would affect the color of an atmosphere,
too.

Also, what you see from space, which would be reflected light, would be very
different from what you would see on the surface, which would be transmitted
light. For instance, if the atmosphere of a planet was very good at
reflecting blue light, the sky might look reddish (or at least that part
immediately around the sun) to an observer on the surface. This might very
well be the case on Uranus and Neptune.

RM

In message , David Sander
writes

Earth's skyglow - the haze that bleeds off into space above the solid
surface visible to any astronaut or aviator flying high enough - is a
deep blue. Earth's sky from the perspective of an observer on the
surface is blue. Mars' skyglow - as tenuous as it is - tends to be a
biscuit brown to orange colour. Mars' sky - according to probes that
have landed there - is a biscuit brown at the horizon tending to a
coffee at the zenith, with an odd blue haze directly around the sun.
Based on photographs from Voyager and Galileo, the best I can come up is
that Jupiter's sky at those high altitudes would be a quite subtle
greyish orange-brown, that a more technically correct backdrop to a
depiction of - say - the Galileo parachute probe would be a quite subtle
greyish orange-brown.

But isn't clear air (or clear hydrogen/helium) always going to be blue,
because it's only the blue light that's scattered? Mars's sky is brown
because of suspended dust, though there was apparently a theory at one
time that it was inherently brown because the atmosphere contained
nitrogen oxides.
I recall a discussion about the green sky on Altair 4 in "Forbidden
Planet" - beautiful, but implausible.
Is there any dust in Jupiter's atmosphere?
--
Rabbit arithmetic - 1 plus 1 equals 10
Remove spam and invalid from address to reply.

In article ,
David Sander wrote:

When Voyager went past Titan, the moon was blanketed in a thick layer of
cloud, leaving a lot of people thinking that's all Titan would *ever*
be. No probe has been near Titan since, but not that long ago Hubble was
pointed in that direction. A series of snapshots showed Titan to have
large dark formations, suggesting the possibility Voyager experienced
what Mariner 9 did at Mars - it arrived at an inopportune time
weather-wise. Unlike Mariner, Voyager simply flew past, unable to hang
around and wait for whatever to subside. With HST however, Titan has
been observed with a comparatively clear sky (if the dark patches
observed are not huge meteorological formations - who knows?).

That's mostly (maybe entirely) because the HST observations were at a longer
wavelength. Voyager couldn't see anything at wavelengths longer than about
650 nm (red-orange) because its vidicon's response died at that point. The
HST images are at 900-1000 nm (near-IR). Titan itself doesn't seem to have
changed much, aside from going through almost a complete seasonal cycle
since Voyager.

--
Kathy Rages

"David Sander" wrote in message
...
Based on photographs from Voyager and Galileo, the best I can come up is
that Jupiter's sky at those high altitudes would be a quite subtle
greyish orange-brown, that a more technically correct backdrop to a
depiction of - say - the Galileo parachute probe would be a quite subtle
greyish orange-brown.

Thoughts?

Sounds like research for Man Conquers Space 2: Let's Get Jiggy
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