New Images of Mercury |
New Images of Mercury |
Aug 2 2007, 01:35 AM
Post
#1
|
|
Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
A Side of Mercury Not Seen By Mariner 10
Gerald Cecil, Dmitry Rashkeev http://xxx.lanl.gov/abs/0708.0146 More than 60,000 images of Mercury were taken at ~29 deg elevation during two sunrises, at 820 nm, and through a 1.35 m diameter off-axis aperture on the SOAR telescope. The sharpest resolve 0.2" (140 km) and cover 190-300 deg longitude -- a swath unseen by the Mariner 10 spacecraft -- at complementary phase angles to previous ground-based optical imagery. Our view is comparable to that of the Moon through weak binoculars. Evident are the large crater Mozart shadowed on the terminator, fresh rayed craters, and other albedo features keyed to topography and radar reflectivity, including the putative huge ``Basin S'' on the limb. Classical bright feature Liguria resolves across the northwest boundary of the Caloris basin into a bright splotch centered on a sharp, 20 km diameter radar crater, and is the brightest feature within a prominent darker ``cap'' (Hermean feature Solitudo Phoenicis) that covers much of the northern hemisphere between longitudes 80-250 deg. The cap may result from space weathering that darkens via a magnetically enhanced flux of the solar wind, or that reddens low latitudes via high solar insolation. Bill |
|
|
Aug 2 2007, 04:55 PM
Post
#2
|
|
Member Group: Members Posts: 117 Joined: 7-December 06 From: Sheffield UK Member No.: 1462 |
Thanks for the post!
Mercury will be pretty much mapped at low resolution prior to the first MESSENGER flyby. -------------------- It's a funny old world - A man's lucky if he gets out of it alive. - W.C. Fields.
|
|
|
Aug 8 2007, 12:38 AM
Post
#3
|
|
Solar System Cartographer Group: Members Posts: 10150 Joined: 5-April 05 From: Canada Member No.: 227 |
Hmmm. that composite map of USGS relief and radar images looks VERY familiar...
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
|
|
Aug 8 2007, 07:26 PM
Post
#4
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
Hmmm. that composite map of USGS relief and radar images looks VERY familiar... Phil To my eyeball, I'd say they actually lifted Phil's image and then made some additions where other coverage was available, but with an awful lot of the work being Phil's. It's an understatement to say that this should deserve credit, and there is none. Unless they coincidentally produced a highly identical product (and it seems very unlikely to me), this is a case of serious dishonesty on the authors' part. |
|
|
Aug 8 2007, 08:13 PM
Post
#5
|
|
Solar System Cartographer Group: Members Posts: 10150 Joined: 5-April 05 From: Canada Member No.: 227 |
It's mine, certainly. The way the poles were handled was unique and would be impossible to duplicate, just to take one point.
I don't care, actually. I do things and put them out there so they will be used by anyone who wants them. That's why I never attach names or copyright symbols to any of my stuff. (except the atlas!) A bit of attribution would be nice, though. Scott Horowitz was using my mosaic of Clementine HIRES images of the lunar south pole in one of his presentations in a similar unattributed way. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
|
|
Aug 8 2007, 08:29 PM
Post
#6
|
|
Senior Member Group: Members Posts: 1582 Joined: 14-October 05 From: Vermont Member No.: 530 |
It looked to me like all of the figures were attributed to other papers. Secondary source?
|
|
|
Aug 8 2007, 09:34 PM
Post
#7
|
|
Solar System Cartographer Group: Members Posts: 10150 Joined: 5-April 05 From: Canada Member No.: 227 |
No, not a secondary source. The reference in this new paper that appears to cite the map is actually to Harmon et al's paper, which was the source of the original radar images, not the composite map. There only was one source for the composite map, and it was my posting on UMSF.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
|
|
Aug 8 2007, 11:14 PM
Post
#8
|
|
Newbie Group: Members Posts: 16 Joined: 8-August 07 Member No.: 3138 |
Hello,
yes the base image is Prof. Stooke's composite, with John Harmon's radar data added to fill some holes. Lower panel ( b ) is new and puts our new Mercury images in the context of some previous work, as stated in the caption. For reasons I won't go into here but which Prof. Stooke will find in his email, the correct attribution to him was not made in the preprint posted at astro-ph. I'm attempting to add it to the paper galley proofs, hopefully that will be successful. I also plan to update the astroph version once I get off travel. Sources for material in the other figures are properly attributed if they are not from NASA archives. If you have any questions on our Mercury imaging, I'm happy to respond (having just registered into this informative newsgroup.) G. Cecil |
|
|
Aug 8 2007, 11:23 PM
Post
#9
|
|
Solar System Cartographer Group: Members Posts: 10150 Joined: 5-April 05 From: Canada Member No.: 227 |
Thanks for this. Perhaps you could say something about the latitudinal extent of imaging which would be possible with your technique. Would the geometry permit global imaging at this resolution, over several orbits, or is it restricted to the longitudes already covered?
Phil Stooke -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
|
|
Aug 8 2007, 11:41 PM
Post
#10
|
|
Newbie Group: Members Posts: 16 Joined: 8-August 07 Member No.: 3138 |
Well, the technique is just frame selection from stacks of short-exposure images, so far batting ~1 in 1000 to get down to ~0.2" resolution. I'm restricted to twilight observations for reasons mentioned in the paper, and from our site at 2700 m elevation in Chile (accessed remotely). This means only elongations that get to ~29 deg elevation, when we bang off 30,000 images. There aren't many of those opportunities left before the MESSENGER flybys, so I don't plan any follow ups. I have other astro programs to execute in the near term, but am working on an instrument for SOAR's adaptive optics system that could image planets in narrow spectral lines (and that I may use for Mercury sodium emission mapping before MESSENGER arrives in orbit). Although we work in twilight, it takes time to install the aperture mask for imaging that would otherwise go to important calibrations of other observing programs.
Leonid Ksanfomality sent me the other day a superb image from July 2006 with "Basin S" smack on the terminator, a bull's eye. Unfortunately, that feature (no question from his data that it is real) was on the bright limb in our data, so we couldn't say much about it in our paper. I imagine that he is working on a follow up of his expanded paper in last April Icarus. Perhaps he will be at the DPS meeting in Orlando. |
|
|
Lo-Fi Version | Time is now: 23rd April 2024 - 09:30 PM |
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. |