Sol 589: Phobos And Deimos? |
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Sol 589: Phobos And Deimos? |
 Sep 2 2005, 08:45 PM
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#1
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 Member  Group: Members Posts: 530 Joined: 24-August 05 Member No.: 471  |
Is the upper shiny spot a bright star or Deimos?
http://qt.exploratorium.edu/mars/spirit/pa...93P2747L1M1.JPG -------------------- - blue_scape / Nico -
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Sep 2 2005, 10:17 PM
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#2
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 Member Group: Members Posts: 331 Joined: 2-May 05 Member No.: 372 |
QUOTE (SigurRosFan @ Sep 2 2005, 04:45 PM) Is the upper shiny spot a bright star or Deimos? http://qt.exploratorium.edu/mars/spirit/pa...93P2747L1M1.JPG  I'd say Deimos. |
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Sep 5 2005, 07:56 PM
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#3
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 Member Group: Members Posts: 521 Joined: 20-April 05 From: Poland Member No.: 299 |
Phobos - crater on surface visible or artefact ?
 Image 2P179138966EFFAEDNP2749R1M1 -------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
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Sep 5 2005, 08:06 PM
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#4
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 Administrator Group: Chairman Posts: 13250 Joined: 8-February 04 Member No.: 1 |
Compare it to the size of the moon as seen in eclipses and you'll find your answer.
Doug |
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Sep 7 2005, 08:45 AM
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#5
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Administrator Group: Chairman Posts: 13250 Joined: 8-February 04 Member No.: 1 |
From Emily's blog..
"Mark had shown these to me yesterday, saying that they hoped to release them this week. He pointed out that "you can actually see Stickney crater" in the image and there was a great "ooh!" from the audience. "We're doing planetary geology!" Steve said." Doug |
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Sep 7 2005, 09:18 AM
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#6
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 Chief Assistant Group: Admin Posts: 1374 Joined: 5-January 05 From: Belgium Member No.: 136 |
Stickney visible...amazing!
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Sep 7 2005, 02:18 PM
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#7
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 Junior Member Group: Members Posts: 90 Joined: 20-April 05 Member No.: 289 |
QUOTE (djellison @ Sep 7 2005, 04:45 AM) From Emily's blog.. "Mark had shown these to me yesterday, saying that they hoped to release them this week. He pointed out that "you can actually see Stickney crater" in the image and there was a great "ooh!" from the audience. "We're doing planetary geology!" Steve said." Doug Doug, do you have a link for the Blog you refewrenced? |
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Sep 7 2005, 02:29 PM
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#8
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Administrator Group: Chairman Posts: 13250 Joined: 8-February 04 Member No.: 1 |
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Sep 7 2005, 02:58 PM
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#9
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Junior Member Group: Members Posts: 90 Joined: 20-April 05 Member No.: 289 |
QUOTE (djellison @ Sep 7 2005, 10:29 AM) Thanks! Some good links from there too. |
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Sep 7 2005, 07:25 PM
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#10
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Member Group: Members Posts: 530 Joined: 24-August 05 Member No.: 471 |
New space.com article: Night Moves: Spirit Mars Rover Turns Astronomer
http://www.space.com/missionlaunches/05090...rit_update.html "Having so much power has allowed group controllers to task Spirit to execute nighttime observing campaigns", Bell told SPACE.com. ... Deimos looks pretty much like a star, far away. But Phobos is an eyeful, Bell observed. ... A soon-to-be-released image will show features on the surface of Phobos, he said, "and this is with not much better than human eye resolution!" I want to see this image. 
-------------------- - blue_scape / Nico -
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Sep 7 2005, 07:31 PM
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#11
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Senior Member Group: Members Posts: 2253 Joined: 30-October 04 Member No.: 105 |
To put this into a "you are there" perspective:
Our Moon has an angular size of 30 arc-minutes (30'). Phobos, at the zenith , will be an oval with an angle of 10' x 7', or about 1/3 the size of our Moon. Deimos would appear as a oval 2.4' x 1.4' in size, or with a barely discernable disk (the human eye can resolve an angle of 1.0-1.5'). Deimos would move east-to-west with the motion of the stars, with a slow esatward drift relative to the starry background. Phobos literally races west to east counter to the starry background, and takes about 4 hours to travel from the Western Horizon to Eastern Horizon. --Bill -------------------- |
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Sep 8 2005, 04:58 AM
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#12
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 Member Group: Members Posts: 809 Joined: 11-March 04 Member No.: 56 |
I can't cite figures, but I recall from a bit of geometry I did a year or so ago that Phobos orbited so close to the surface of Mars that its distance from the observer when on the horizon would be substantially greater than its distance when directly overhead; and that this would mean that Phobos would appear noticeably smaller when on the horizon, not from some optical illusion, but because it would actually be much farther away.
I should add that although I've seen several maps of Phobos, I've never been able to figure out from them which parts of Phobos are visible from the surface of Mars. Images of Phobos from space obviously could be taken at a variety of angles. So I'm looking forward to getting a Martian's-eye view that would help solve my uncertainty on this question: what does Phobos look like from Mars? So far I've seen Phobos silhouetted in lunar eclipse against the sun, and an overexposed image of Phobos with no internal detail -- but I'd love to see something a little clearer. |
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Sep 8 2005, 01:41 PM
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#13
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 Special Cookie Group: Members Posts: 2149 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
QUOTE (peter59 @ Sep 5 2005, 07:56 PM) Phobos - crater on surface visible or artefact ? Image 2P179138966EFFAEDNP2749R1M1 Here's a comparison: http://i16.photobucket.com/albums/b14/ustrax3/phobos.jpg Is that an abyss on the top?!!  
-------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Sep 8 2005, 02:33 PM
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#14
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 Member Group: Members Posts: 554 Joined: 29-March 05 Member No.: 221 |
QUOTE (ustrax @ Sep 8 2005, 02:41 PM) Here's a comparison: Is that an abyss on the top?!! Oh Ustrax.... the people in my office are looking at me funny as i couldn't stop myself laughing at your comment.. I'm starting to think there may be something Freudian about your predisposition to abyssal terrain.... |
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Sep 8 2005, 02:47 PM
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#15
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Special Cookie Group: Members Posts: 2149 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
QUOTE (paxdan @ Sep 8 2005, 02:33 PM) Oh Ustrax.... the people in my office are looking at me funny as i couldn't stop myself laughing at your comment.. I'm starting to think there may be something Freudian about your predisposition to abyssal terrain.... Freud?! Who cares about Freud when you got all those abysses?!! http://i16.photobucket.com/albums/b14/ustrax3/freud.jpg 
-------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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