Phoenix - spring images, HiRISE views of Phoenix after the long, long winter |
Phoenix - spring images, HiRISE views of Phoenix after the long, long winter |
Apr 18 2010, 02:44 PM
Post
#136
|
|
Senior Member Group: Members Posts: 4256 Joined: 17-January 05 Member No.: 152 |
One point that hasn't been mentioned is that even if you register the ground around Phoenix perfectly between the "before" and "after" frames, then Phoenix itself won't be registered if the viewing angle is different between the two images. That's because the top of the body and arrays is something like a metre above the ground. If there's a difference in viewing angle of order 30 degrees that would produce a significant shift in deck and arrays. This might explain why it looks like Phoenix shifted/collapsed. This could be corrected for given those viewing angles.
In terms of the shadows, it's possible that topography or albedo are confusing the issue. My impression is that both arrays are still up, and just coated in dust so they match the appearance of the ground. If one had tipped, the illumination angle on that array would be very different from the ground and it should look considerably brighter or dimmer than the ground. I'm also curious whether the small frosty patches just north of Phoenix could coincide with the major digs, like Dodo/Goldilocks or Snow White? Could the ice exposed in those digs encourage frost/ice around them? My guess is the visible patches are too far from the body, but I haven't done any measurements. |
|
|
Apr 18 2010, 04:18 PM
Post
#137
|
|
Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
Good point. Now, if someone could identify the IDs of those two images the information about the "viewing angle" can be easily found on their respective webpages.
|
|
|
Apr 18 2010, 04:30 PM
Post
#138
|
|
Senior Member Group: Members Posts: 1452 Joined: 26-July 08 Member No.: 4270 |
What kind of difference in angle would be required to make an apparent shift of more than the diameter of the lander?
-------------------- -- Hungry4info (Sirius_Alpha)
|
|
|
Apr 18 2010, 04:42 PM
Post
#139
|
|
Senior Member Group: Members Posts: 4256 Joined: 17-January 05 Member No.: 152 |
To me it looks like the shift is only roughly half a solar array diameter. That would be easy to achieve.
|
|
|
Apr 18 2010, 08:24 PM
Post
#140
|
|
Martian Photographer Group: Members Posts: 353 Joined: 3-March 05 Member No.: 183 |
I'm also curious whether the small frosty patches just north of Phoenix could coincide with the major digs... The patches seem to be about where the lander + 2 arrays shadow would have been in mid-afternoon 1-2 months before the picture. They don't line up with the digs, and seem to far away. |
|
|
Apr 19 2010, 07:41 AM
Post
#141
|
|
Senior Member Group: Members Posts: 2173 Joined: 28-December 04 From: Florida, USA Member No.: 132 |
In terms of the shadows, it's possible that topography or albedo are confusing the issue. I'm pretty confused as to what I'm looking at. Still, it seems quite an accomplishment of circumstances to eliminate any trace of a shadow from the array on the right side. What if it is not tipped, but laying flat on the surface?
...My impression is that both arrays are still up, and just coated in dust so they match the appearance of the ground. If one had tipped, the illumination angle on that array would be very different from the ground and it should look considerably brighter or dimmer than the ground.... |
|
|
Apr 19 2010, 07:44 AM
Post
#142
|
|
Senior Member Group: Members Posts: 2173 Joined: 28-December 04 From: Florida, USA Member No.: 132 |
|
|
|
May 14 2010, 08:00 AM
Post
#143
|
|
Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
Final Attempts to Hear from Mars Phoenix form 17 to 21 May
|
|
|
Lo-Fi Version | Time is now: 27th September 2024 - 04:41 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |