Mars color images

On Wed, 7 Jan 2004 2:05:27 -0600, Subz wrote
(in message ):

From: "Subz"
Newsgroups: sci.astro.amateur, uk.sci.astronomy

"Martin" wrote in message
...
Anyone else taken a good close look at that rock that appears on the left
hand side of the frame, about half way up and about and about a tenth of
the
way in? It looks like its got a couple of deep recesses or even holes in
it.

Martin

Similar to rocks found in large bodies of water, where a small stone has
been caused to "bore" a hole into the rock it is "sat" on by the action of
water. The stone becomes trapped by the small depression it has made and
continues to deepen it. At least that's my understanding of it.

According to my grandfather that was one way to make a really good marble. I
used to have a couple of his that he made as a kid. (Or collected from others
in games of marbles.) He would look for rocks in the streams with holes in
them, than put an over-sized marble-to-be into the hole and check back in a
few months.)

I was
terrible at GeoSci. I dare say the same could be caused by Martian sand
storms, as powerful as they are.

Does look like a skull though!

Could it be... Marvin???
--
Harry F. Leopold
aa #2076
AA/Vet #4
The Prints of Darkness

"Nothing can stand up to atheistic critical examination. You guys are the
proctologists of Religion." - angelicusrex

I can't believe that JPL is stuck for web space and bandwidth. They must
have anticiapted that people are gonna want to see this stuff!!!!!

Martin

They have had something like 2 billion hits on the website. They say
they have 1300 web servers but even that many can't keep up.

Does anyone else think that the alignment of the mosaic is a bit crude?
There's one part (lower-right) that is really shoddy alignment.

Petty criticism, I know, but it just bugs me.
Paul.

"Paul Neave" wrote in message
...
Does anyone else think that the alignment of the mosaic is a bit crude?
There's one part (lower-right) that is really shoddy alignment.

Petty criticism, I know, but it just bugs me.
Paul.



I think they were just keen to get the pictures out there. Have you seen the
latest website update? They talk about people waiting till the demand drops
off, but we are only just at the start of this and of course another Rover
to land in a couple of weeks. I really think JPL need the help of the larger
scientific community here and get plenty of mirrors up of their site.

The demand on their site is going to go up, not down. You can't download the
Quicktime movies now (they make a neat screensaver) and I really want to see
the full high res images, so they need to get mirrors up soon. They managed
that for the Maestro software.

Martin

"Mike Humberston" wrote in message
...
"Bob Schmall" wrote:

Question: must the rounding be the result of flowing water? A lake bed
would
not seem to be the place for this type of erosion, unless the rocks were
in
place at some other time before or after the lake formed.

No. Rounding can result from other forms of erosion, e.g. by the
wind (containing sand grains) or but just sitting in an
environment where the rock is heated during the day and cools
during the night giving differential expansion and consequent
exfoliation.

Most of the rocks on the picture are not particularly rounded (as
with pebbles from a river or beach) but have a faceted look
which if often indicative of wind erosion. Note also the
undercutting on the windward side.

--
Mike Humberston

Mike:
Thanks for a cogent reply. The question was intended to start a discussion
and it has, but only a couple of posts were related to the original topic.
NASA says that wind erosion is the likely cause of the softened profiles and
polishing.
As for the "holes" in a couple of rocks, could they have been caused by an
embedded rock or rocks that dropped out? This is a common effect here on
Earth.

Bob

i have assumed that most of the holes are artifacts of a lava flow,
you know, bubbles? --Loren


In article , Bob Schmall wrote:

"Mike Humberston" wrote in message
...
"Bob Schmall" wrote:
Question: must the rounding be the result of flowing water? A lake bed
would
not seem to be the place for this type of erosion, unless the rocks were
in place at some other time before or after the lake formed.

No. Rounding can result from other forms of erosion, e.g. by the
wind (containing sand grains) or but just sitting in an
environment where the rock is heated during the day and cools
during the night giving differential expansion and consequent
exfoliation.

Most of the rocks on the picture are not particularly rounded (as
with pebbles from a river or beach) but have a faceted look
which if often indicative of wind erosion. Note also the
undercutting on the windward side.

--
Mike Humberston

Mike:
Thanks for a cogent reply. The question was intended to start a discussion
and it has, but only a couple of posts were related to the original topic.
NASA says that wind erosion is the likely cause of the softened profiles and
polishing.
As for the "holes" in a couple of rocks, could they have been caused by an
embedded rock or rocks that dropped out? This is a common effect here on
Earth.

Bob

Does anyone else think that the alignment of the mosaic is a bit crude?
There's one part (lower-right) that is really shoddy alignment.

The geometry makes it impossible for all edges to meet perfectly. For
them all to meet perfectly the two axis of rotation of the pancam
would have to be exactly about the camera lens. It is almost
impossible to do this in real life. On Spirit, the rotation points are
slightly behind the lenses for azimuth. They are also inboard of each
eye for sideways rotation, because it has 2 cameras for stereo vision
(actually 4 including the nav cams).

You could paste 2 pictures together well... but you would have lots of
problems trying to paste 12 together. Also, Each eye can only take
certain parts of the light spectrum, you need data from both eyes to
get the whole spectrum, and combing the color portions from different
perspectives is interesting.

Peterson, David wrote:
You could paste 2 pictures together well... but you would have lots of
problems trying to paste 12 together. Also, Each eye can only take
certain parts of the light spectrum, you need data from both eyes to
get the whole spectrum, and combing the color portions from different
perspectives is interesting.

All true, but as long as you have points of reference it's a fairly easy
process to warp each image to remove the distortion so that they all
match up. I'm surprised that this geometry wasn't all worked out in
software before they launched. There may be some missing or mangled
data in there. The DSN isn't all that reliable at getting the data to
JPL intact the first time around. The only other thing I can come up
with is that the geometry has either changed or was expected to change
significantly after the long trip (and all that bouncing around). In
time, as with the Pathfinder images, these will all be seamless mosaics.
Look for the final "Success Panorama" to be pretty seamless (and huge).

Clear skies,
Greg

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools Software for the Observer:
http://www.skyhound.com/cs.html

Skyhound Observing Pages:
http://www.skyhound.com/sh/skyhound.html

"Peterson, David" wrote:
/
You could paste 2 pictures together well... but you would have lots of
problems trying to paste 12 together. Also, Each eye can only take
certain parts of the light spectrum, you need data from both eyes to
get the whole spectrum, and combing the color portions from different
perspectives is interesting.

Do they actually use both cameras for the true color panorama? That is
surprising. I would have thought that they would use both cameras for
the 3-D stereo but create the true color image from just the left camera,
which has 3 blue filters, 1 green and 3 red. The right camera has 7 far
red/IR filters and 1 blue. For spectral analysis, the right camera is the
one to use, but I can't see how it can contribute to a true color image.

Do they actually use both cameras for the true color panorama? That is
surprising. I would have thought that they would use both cameras for
the 3-D stereo but create the true color image from just the left camera,
which has 3 blue filters, 1 green and 3 red. The right camera has 7 far
red/IR filters and 1 blue. For spectral analysis, the right camera is the
one to use, but I can't see how it can contribute to a true color image.


You are correct. I just heard they some where... but looking at the
fliter wheels you do get color from one eye. I think when the make the
3-D color, first they make the 3-D from grayscale images and then
colorize them from the one color eye.