Full Version: Out Of The Crater At Last.
Why is the upper rim of the large crater in the distance so bright? And is that more bedrock around smaller craters in the foreground?
I believe the whitish patches, including the one near the rock are bounce marks left by the airbags
There are some incredibly beautiful dune features too:
There are some incredibly beautiful dune features too:
Here's 'the look back'
JPL/MIPL does it better than I, thats for sure, here's their version instead:
JPL/MIPL does it better than I, thats for sure, here's their version instead:
QUOTE
Sunspot wrote: I believe the whitish patches, including the one near the rock are bounce marks left by the airbags
I don't think those white spots are bounce marks, the bounce marks actually change the texture of the surface...flattens it out due to the 'bonding' agents in the soil whatever they may be (what was it? saline slush?)
Anyway, those just look like areas that have exposed bedrock, probably a 'dip' in the plain where mini-dust devils clear away the material.
I'm sooooo happy it finally got out of the crater...not that I'm unhappy about the science they've done there, and I'm awaiting the announcement on Tuesday. But I can't wait for it to go rovin'.
Eric P / MizarKey
QUOTE (MizarKey @ Mar 23 2004, 02:26 AM)
QUOTE
Sunspot wrote: I believe the whitish patches, including the one near the rock are bounce marks left by the airbags
I don't think those white spots are bounce marks, the bounce marks actually change the texture of the surface...flattens it out due to the 'bonding' agents in the soil whatever they may be (what was it? saline slush?)
Anyway, those just look like areas that have exposed bedrock, probably a 'dip' in the plain where mini-dust devils clear away the material.
Nope, they are indeed bounce-marks. Compare the image with the rock and white (not really white, just brighter) spots with this panorama, taken from inside the crater:
http://marsrovers.jpl.nasa.gov/gallery/pre...-B041R1_br2.jpg
Those are indeed bounce-marks, and we are just seeing them from a different angle.
The reason the bounce-marks look brighter is that they push the darker larger objects down into the brighter sand. No saline solution or water needed to explain that one.
It seems the heatshield is right onroute to the crater 
Nice place to stop to take a rest
Nice place to stop to take a rest
QUOTE (remcook @ Mar 23 2004, 04:29 PM)
It seems the heatshield is right onroute to the crater
Nice place to stop to take a rest
Nice place to stop to take a rest
It's on route all right - but not till after the crater when they start heading south
Doug
NASA just released their official Navcam panorama: http://marsrovers.jpl.nasa.gov/gallery/pre.../20040323a.html
Here is the thumbnail version:
Here is the thumbnail version:
QUOTE (djellison @ Mar 23 2004, 04:59 PM)
QUOTE (remcook @ Mar 23 2004, 04:29 PM)
It seems the heatshield is right onroute to the crater
Nice place to stop to take a rest
Nice place to stop to take a rest
It's on route all right - but not till after the crater when they start heading south
Doug
sorry...I took that single rock (the only one in the surrounding, which Opportunity hit while bouncing) to be the heatshield. Anyway...that rock is right in the middle of the path to the crater.
QUOTE
Sunspot wrote: I believe the whitish patches, including the one near the rock are bounce marks left by the airbags
MizarKey wrote: I don't think those white spots are bounce marks, the bounce marks actually change the texture of the surface...flattens it out due to the 'bonding' agents in the soil whatever they may be (what was it? saline slush?)
Anyway, those just look like areas that have exposed bedrock, probably a 'dip' in the plain where mini-dust devils clear away the material.
lars_J wrote: Nope, they are indeed bounce-marks. Compare the image with the rock and white (not really white, just brighter) spots with this panorama, taken from inside the crater:
http://marsrovers.jpl.nasa.gov/gallery/pre...-B041R1_br2.jpg
Those are indeed bounce-marks, and we are just seeing them from a different angle.
MizarKey wrote: I don't think those white spots are bounce marks, the bounce marks actually change the texture of the surface...flattens it out due to the 'bonding' agents in the soil whatever they may be (what was it? saline slush?)
Anyway, those just look like areas that have exposed bedrock, probably a 'dip' in the plain where mini-dust devils clear away the material.
lars_J wrote: Nope, they are indeed bounce-marks. Compare the image with the rock and white (not really white, just brighter) spots with this panorama, taken from inside the crater:
http://marsrovers.jpl.nasa.gov/gallery/pre...-B041R1_br2.jpg
Those are indeed bounce-marks, and we are just seeing them from a different angle.
Never mind...I misread Sunspots post, he posted the image of the 'lovely dunes' which included the white spots and I thought he was asking if they were bounce marks. My bad.
Eric P / MizarKey
I'm not sure if those two depressions with the "white spots" in them are airbag marks (what I thought at first too). They are referenced here by JPL, nicknamed "homeplate" and "first base". They are not referred to as airbag marks though, just interesting depressions, with possible bits of bedrock exposed in them. See "Twin Dimples Intrigue Scientists" at end of this page:
http://marsrovers.jpl.nasa.gov/gallery/pre.../20040323a.html
http://marsrovers.jpl.nasa.gov/gallery/pre.../20040323a.html
I believe that the airbag marks form a trail heading out the right side of the crater, as viewed in the navcam panorama (the opposite side as the "depressions"). The MOC image of the lander LINK: 2004 MOC ROTO image shows the 'first bounce' and effects of rocket firing (visible lightening of the ground) as being about 150-160 degrees south of Opportunity's landing crater. There is a large, visibily lighter area in the Navcam pano (bracketed below) and the bounce marks I think I can see from that area to the crater:
It matches up with the angles given in the NASA large panorama of the site (150-160 degrees).[U]
It matches up with the angles given in the NASA large panorama of the site (150-160 degrees).[U]
Yep, "homeplate" and "first base" are not bouncemarks, I was mistaken earlier. The bounce marks (and the small rock) are on the opposite side of the rover relative to the exposed flat areas.
I thought the plain would be pretty boring until Endurance crater is reached, but there seems to be yet more things to look at. Spirit must be getting pretty jealus of its sister rover.
I thought the plain would be pretty boring until Endurance crater is reached, but there seems to be yet more things to look at. Spirit must be getting pretty jealus of its sister rover.
Yeah, it looks like Spirit does all the work and Opportunity gets the credit 
A new view of the rock hit by the aribags:
http://marsrovers.jpl.nasa.gov/gallery/all...30P2557L7M1.JPG
http://marsrovers.jpl.nasa.gov/gallery/all...30P2557R1M1.JPG
How far away is it and how large??
http://marsrovers.jpl.nasa.gov/gallery/all...30P2557L7M1.JPG
http://marsrovers.jpl.nasa.gov/gallery/all...30P2557R1M1.JPG
How far away is it and how large??
>How far away is it and how large??
Based on the left and right images, there's a parallax of 92 pixels at the rock. The distance equation for Opportunity's pancam is:
D = 1071/(130 - N)
D = 1071/(130 - 92) = 28.2 meters
The width of the rock is 54 pixels. At 0.28 mrad/pixel (pancam spec) that's 15 mrad. Width then would be 28.2*0.015 = 0.42 m.
The width of the bounce mark is 223 pixels or 1.8 m.
Joe
Based on the left and right images, there's a parallax of 92 pixels at the rock. The distance equation for Opportunity's pancam is:
D = 1071/(130 - N)
D = 1071/(130 - 92) = 28.2 meters
The width of the rock is 54 pixels. At 0.28 mrad/pixel (pancam spec) that's 15 mrad. Width then would be 28.2*0.015 = 0.42 m.
The width of the bounce mark is 223 pixels or 1.8 m.
Joe
QUOTE (jmknapp @ Mar 25 2004, 03:51 PM)
28.2 meters
1 days rove.
We need some sort of applet or little VB app to do those sums for us
Doug
>We need some sort of applet or little VB app to do those sums for us
OK, I'll do a little forms-based web page, probably tomorrow (engaged rest of today).
Even with such a calculator, the main work is downloading the two pictures and reading them into an image processing program to get the pixel locations.
OK, I'll do a little forms-based web page, probably tomorrow (engaged rest of today).
Even with such a calculator, the main work is downloading the two pictures and reading them into an image processing program to get the pixel locations.
OK, here's a bare-bones web-based stereoscopic range calculator for the MERs:
>>MER Parallax Calculator<<
What you have to do is from a l/r stereo pair (EFF) from the pancam or navcam, identify an object you want to calculate the range to. That object should have a small feature on it that you can locate down to the accuracy of one pixel. Then input the horizontal position of this feature in the left and right images. If desired, input an object dimension in pixels (e.g. width).
>>MER Parallax Calculator<<
What you have to do is from a l/r stereo pair (EFF) from the pancam or navcam, identify an object you want to calculate the range to. That object should have a small feature on it that you can locate down to the accuracy of one pixel. Then input the horizontal position of this feature in the left and right images. If desired, input an object dimension in pixels (e.g. width).
great stuff
Doug
Doug
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