View Single Post
  #22  
Old February 19th 04, 02:05 AM
Paul Morris
external usenet poster
 
Posts: n/a
Default unusual pebble shape

In article , "Icarus"
wrote:

Paul Morris wrote:

snip
right-hand image (Sol 5 navcam).

So the navcam image is just outside the range that would
reveal the "bug."


OK I know I'm being really pedantic now but... :-) The aspect
ratio for the two images is different - The rock outcrop is
significantly wider in the left hand image than in the right,
although the height is the same. Hence it seems to me that we
should expect the distance from the small white blob to the
'object' to be smaller in the right-hand image than in the left.
I think that puts it in the picture still. In fact, I've
annotated the pair of images to show how I think the faint
features in the two images correspond - go back and have a look:

http://www.envf.port.ac.uk/jr/object.html

I'm sure it's all academic anyway, since the thing didn't appear
in the hazcam images after the rover left the lander, which
suggests it probably did blow away, and it was probably only a
bit of crap from the lander anyway... :-)


You are correct about the aspect ratio. Thanks for clarifying that.

In a way, it is a relief to know the object was gone before the rover
started rolling. At least it did not get ground into the dust!

It seems a little implausible, though, that the object could have blown
away. There is no sign of dust devils at the site. With a martian atmosphere
of less than 10 millibars and a sheltered location in the crater, it doesn't
seem like the wind would be strong enough to move an object of that
size, unless it was of extremely low density.

Paul

--
Email: lastname at best dot com. No spam please.
All spam will be complained to sender's ISP.