APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Comments and questions about the APOD on the main view screen.
User avatar
Chris Peterson
Abominable Snowman
Posts: 16818
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by Chris Peterson » Wed Feb 06, 2013 1:04 am

Ann wrote:
APOD Robot wrote:
What if you saw your shadow on Mars
Six more weeks of winter! :evil:
I was thinking the same thing. Except a Martian year is twice as long, so maybe that should be twelve more weeks?
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
MargaritaMc
Look to the Evenstar
Posts: 1836
Joined: Wed Jan 09, 2013 10:14 pm
Location: 28°16'7"N 16°36'20"W

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by MargaritaMc » Wed Feb 06, 2013 10:13 am

Click to play embedded YouTube video.
I would think that everyone has watched this video a zillion times - but as I am still excited and awed by the achievement of putting Curiosity on Mars, :clap: I decided to post it.

Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS

User avatar
BMAONE23
Commentator Model 1.23
Posts: 4076
Joined: Wed Feb 23, 2005 6:55 pm
Location: California

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by BMAONE23 » Wed Feb 06, 2013 2:54 pm

Chris Peterson wrote:
Ann wrote:
APOD Robot wrote:
What if you saw your shadow on Mars
Six more weeks of winter! :evil:
I was thinking the same thing. Except a Martian year is twice as long, so maybe that should be twelve more weeks?
I thought about that too.
But isn't the end of winter always 6 to 7 weeks after Feb 2?

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by neufer » Wed Feb 06, 2013 3:34 pm

BMAONE23 wrote:
isn't the end of winter always 6 to 7 weeks after Feb 2?
http://en.wikipedia.org/wiki/Groundhog_Day#Alternative_origin_theories wrote:
<<In western countries in the Northern Hemisphere, the official first day of spring is almost seven weeks (46–48 days) after Groundhog Day, on March 20 or March 21. The custom could have been a folk embodiment of the confusion created by the collision of two calendrical systems. Some ancient traditions marked the change of season at cross-quarter days such as Imbolc when daylight first makes significant progress against the night. Other traditions held that spring did not begin until the length of daylight overtook night at the Vernal Equinox. So an arbiter, the groundhog/hedgehog, was incorporated as a yearly custom to settle the two traditions. Sometimes spring begins at Imbolc, and sometimes
winter lasts six more weeks until the equinox
.>>
Art Neuendorffer

User avatar
MargaritaMc
Look to the Evenstar
Posts: 1836
Joined: Wed Jan 09, 2013 10:14 pm
Location: 28°16'7"N 16°36'20"W

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by MargaritaMc » Wed Feb 06, 2013 5:33 pm

Keyman wrote:In the lower left, the 'front bumper' of the rover has "Curiosity" spelled out, but it appears to be cut and shifted in the middle. Am I correct in assuming this is a 'defect' caused by splicing together the pieces of the mosaic?
I wrote to Photojournal at JPL-NASA as I also was curious about this.
This is the conversation:
On 6 Feb 2013 16:58, "Guy W (1871)"wrote:
THis is a mosaic image, assembled from component images.  Some of the alignments in this process are better than others.  The features closest to the camera, such as the Curiosity label on the hardware, tend to be harder to align than more distant features.

 

From: B. Karen (388L)
Sent: Wednesday, February 06, 2013 8:52 AM
To: Guy W (1871)
Subject: FW: Is the photo not lined up correctly?

 

This is interesting, Guy. Could you respond to Mrs. McE?

Thank you,

Karen

 

From: margarita mc
Sent: Wednesday, February 06, 2013 7:41 AM
To: photojournal
Subject: Is the photo not lined up correctly?

 

http://photojournal.jpl.nasa.gov/catalog/PIA16563

The above photo was used as the Apod for February 5th 2013 and was discussed on the related Forum ( http://asterisk.apod.com/viewtopic.php?f=9&t=30666)

Someone noted that the name Curiosity on the rover doesn't line up correctly. I looked at the original at your site in high resolution and saw that it really does not align. However, the relevant shadows DO seem aligned.

I have attached the detail in question and would be really interested in your comments - which I would request permission to post at Asterisk.

Many thanks
Margarita
I was really impressed that they made the effort to reply and did so so quickly.

Margarita

PS. I sent a close up of the name " Curiosity' cropped from the high resolution image I downloaded, but I don't think I can post it here as the smallest that I could get it was still over 500 kb
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
&mdash; Dr Debra M. Elmegreen, Fellow of the AAAS

User avatar
geckzilla
Ocular Digitator
Posts: 9172
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by geckzilla » Wed Feb 06, 2013 8:51 pm

Try uploading it to http://www.imgur.com, Marg.
Just call me "geck" because "zilla" is like a last name.

User avatar
MargaritaMc
Look to the Evenstar
Posts: 1836
Joined: Wed Jan 09, 2013 10:14 pm
Location: 28°16'7"N 16°36'20"W

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by MargaritaMc » Wed Feb 06, 2013 9:14 pm

geckzilla wrote:Try uploading it to http://www.imgur.com, Marg.
I think that would be over- kill! The image is just a close- up of the 5th Feb Apod.
I did look at the imgur site, but the hassle of signing up put me off - I can never work out the graphics that you have to copy in order to prove that you're not a robot as I just can't see them properly.
Best
Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
&mdash; Dr Debra M. Elmegreen, Fellow of the AAAS

User avatar
bystander
Apathetic Retiree
Posts: 21074
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by bystander » Wed Feb 06, 2013 9:40 pm

PIA16563_cut.jpg
You do not have the required permissions to view the files attached to this post.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
Chris Peterson
Abominable Snowman
Posts: 16818
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by Chris Peterson » Wed Feb 06, 2013 10:04 pm

Keyman wrote:In the lower left, the 'front bumper' of the rover has "Curiosity" spelled out, but it appears to be cut and shifted in the middle. Am I correct in assuming this is a 'defect' caused by splicing together the pieces of the mosaic?
The ideal camera would have a fixed, point source aperture. That is, no matter what direction it was aimed, the aperture that collected the light would sit in the same place. In practice, that is not the case. The camera sits on a pan/tilt mechanism at the end of an arm. In order to look around, the camera has to be moved. That creates parallax- objects in the foreground move with respect to objects in the background, which makes it impossible to perfectly align mosaic images using simple image processing methods. It is possible to get perfect mosaics by mapping the camera data to a physical model and then re-rendering it- something that is done in certain cases, but generally isn't worthwhile in most images (and even then, there's usually no reason to map pieces of the rover).
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
MargaritaMc
Look to the Evenstar
Posts: 1836
Joined: Wed Jan 09, 2013 10:14 pm
Location: 28°16'7"N 16°36'20"W

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by MargaritaMc » Wed Feb 06, 2013 10:21 pm

Chris Peterson wrote
That creates parallax- objects in the foreground move with respect to objects in the background, which makes it impossible to perfectly align mosaic images using simple image processing methods
Ah ha! So both this Apod and the one we had recently of the Moon rising have actually served as very useful teaching tools about parallax. It has helped me to grasp what is involved a bit more, anyway.

Margarita

PS Thank you, bystander for posting the image.
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
&mdash; Dr Debra M. Elmegreen, Fellow of the AAAS

User avatar
Beyond
500 Gigaderps
Posts: 6889
Joined: Tue Aug 04, 2009 11:09 am
Location: BEYONDER LAND

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by Beyond » Wed Feb 06, 2013 11:34 pm

IF you don't keep track of your feet... you'll be seeing stars, but not the ones in the sky :!: :lol2:
To find the Truth, you must go Beyond.

User avatar
MargaritaMc
Look to the Evenstar
Posts: 1836
Joined: Wed Jan 09, 2013 10:14 pm
Location: 28°16'7"N 16°36'20"W

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by MargaritaMc » Wed Feb 06, 2013 11:39 pm

Beyond wrote:IF you don't keep track of your feet... you'll be seeing stars, but not the ones in the sky :!: :lol2:
Ah, but that is where it is so useful to be a wheelchair user... :D
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
&mdash; Dr Debra M. Elmegreen, Fellow of the AAAS

User avatar
Beyond
500 Gigaderps
Posts: 6889
Joined: Tue Aug 04, 2009 11:09 am
Location: BEYONDER LAND

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by Beyond » Wed Feb 06, 2013 11:48 pm

MargaritaMc wrote:
Beyond wrote:IF you don't keep track of your feet... you'll be seeing stars, but not the ones in the sky :!: :lol2:
Ah, but that is where it is so useful to be a wheelchair user... :D
You got me on that one :!: Although... if you don't set your brake correctly on a grade, you still may be seeing stars... after a wild ride :!: :mrgreen:
To find the Truth, you must go Beyond.

User avatar
geckzilla
Ocular Digitator
Posts: 9172
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by geckzilla » Thu Feb 07, 2013 3:13 am

MargaritaMc wrote:
geckzilla wrote:Try uploading it to http://www.imgur.com, Marg.
I think that would be over- kill! The image is just a close- up of the 5th Feb Apod.
I did look at the imgur site, but the hassle of signing up put me off - I can never work out the graphics that you have to copy in order to prove that you're not a robot as I just can't see them properly.
Best
Margarita
You don't have to sign up. Next to the imgur logo is a cloud with an arrow on it. You can click that and paste the link in and it will host it for you and also create multiple images sizes to link.
Just call me "geck" because "zilla" is like a last name.

User avatar
MargaritaMc
Look to the Evenstar
Posts: 1836
Joined: Wed Jan 09, 2013 10:14 pm
Location: 28°16'7"N 16°36'20"W

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by MargaritaMc » Thu Feb 07, 2013 8:20 am

geckzilla wrote:
You don't have to sign up. Next to the imgur logo is a cloud with an arrow on it. You can click that and paste the link in and it will host it for you and also create multiple images sizes to link.
I tried this but it wouldn't work. Problem is not with imgur - there is some kind of incompatibility between this tablet PC I use and "???" . It is a Google Nexus 7, running the latest version of Android.

But thanks for the idea.
Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
&mdash; Dr Debra M. Elmegreen, Fellow of the AAAS

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Curiosity completes 1st drill into Mars rock

Post by neufer » Sat Feb 09, 2013 5:02 pm

http://www.usatoday.com/story/news/nation/2013/02/09/curiosity-drill-mars-rock/1904705/ wrote:
Click to play embedded YouTube video.
Curiosity rover completes 1st drill into Mars rock
USA TODAY, 11:41a.m. EST February 9, 2013

<<LOS ANGELES (AP) — To scientists' excitement, the Curiosity rover has completed its first drilling on Mars and is preparing to analyze a pinch of powdery rock. Images beamed back to Earth overnight showed a fresh drill hole next to a test hole the rover made earlier. The feat marked yet another milestone for Curiosity, which landed last summer to hunt for the chemical building blocks of life. While previous Mars rovers have chiseled away at rocks, it's the first time one drilled down to obtain a sample. The exercise was so complex that engineers spent several days commanding Curiosity to drill test holes. The next task is to transfer the powder to Curiosity's onboard laboratories to study the chemical makeup. After the drilling activities, Curiosity will spend nine months driving to a mountain.>>
Art Neuendorffer

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Ventifact or Ventific(a)tion?

Post by neufer » Tue Feb 12, 2013 1:05 pm

Beyond wrote:
That "thing" in the upper center of neufer's picture, greatly resembles the business end of a ballpeen hammer. At least to me.
http://www.universetoday.com/99890/scientist-explains-the-weird-shiny-thing-on-mars/#more-99890 wrote: Scientist Explains the Weird Shiny Thing on Mars
by Nancy Atkinson on February 12, 2013

<<Images from the Curiosity rover showed what looked like a piece of shiny metal sticking out from a rock. Some of our readers suggested that it might be a handle or knob of some kind. It’s a knob, yes, says Ronald Sletten from the Mars Science Laboratory team, but a completely natural formation. Sletten, from the University of Washington, explained that, not surprisingly, it is actually a part of the rock that is different — harder and more resistant to erosion — than the rest of the rock it’s embedded in.

On Earth, as on Mars, “often you can see knobs or projections on surfaces eroded by the wind, particularly when a harder, less erodible rock is on top,” Sletten said, via an email to Universe Today from the Jet Propulsion Laboratory media relations office. “The rock on top of the projection is likely more resistant to wind erosion and protects the underlying rock from being eroded.”

As far as why it appears shiny, Sletten said, “The shiny surface suggests that this rock has a fine grain and is relatively hard. Hard, fine grained rocks can be polished by the wind to form very smooth surfaces. It also may be shiny because it is wind-blasted and therefore dust-free, Sletten said, “while the surfaces not directly being eroded by wind may have a fine layer of reddish dust or rock-weathering rind. The sandblasted surfaces may reveal the inherent rock color and texture.”

He added that the object is an interesting study in how wind and the natural elements cause erosion and other effects on various types of rocks. In looking at a zoomed-in close-up of the “knob” or protuberance from the rock, Sletten said, “This knob has a different type of rock on the end of the projection. This rock may vary in composition or the rock grain size may be smaller.”

Because of the winds on Mars, there is quite a bit of erosion of rock, visible in the image above, as well as in many images from all the Mars rovers and landers. These type of surfaces are called “ventifacted” — wind-eroded surfaces caused by many fine particles of dust or sand impacting the surface over time. Areas of rocks may appear sculpted, as softer parts erode more easily or they may reflect small scale wind patterns, Sletten said.

So, this weird shiny thing on Mars is nothing too out of the ordinary —
not a door handle, hood ornament or not even Richard Hoagland’s bicycle.>>
Art Neuendorffer

User avatar
bystander
Apathetic Retiree
Posts: 21074
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: Ventifact or Ventific(a)tion?

Post by bystander » Wed Feb 13, 2013 12:19 am

neufer wrote:
Scientist Explains the Weird Shiny Thing on Mars
Universe Today by Nancy Atkinson on February 12, 2013
Another Weird Shiny Thing on Mars
Universe Today | Nancy Atkinson | 2013 Feb 05

Mars Rock Takes Unusual Form
NASA | JPL-Caltech | MSL Curiosity | 2013 Feb 11
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 1508
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by JohnD » Fri Feb 15, 2013 10:19 pm

Some good images of the item here: http://www.jpl.nasa.gov/images/msl/2013 ... ifacts.pdf

Surely Curiosity will go over for a closer look. or else, isn't this an ideal target for the Chemcam?

JOhn

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Mars: Shadow at Point Lake (2013 Feb 05)

Post by neufer » Sat Feb 16, 2013 3:20 am

JohnD wrote:
Some good images of the item here: http://www.jpl.nasa.gov/images/msl/2013 ... ifacts.pdf

Surely Curiosity will go over for a closer look. or else, isn't this an ideal target for the Chemcam?
I'm betting that it's an iron meteorite that had splashed into the water and gotten stuck in the mud.
Art Neuendorffer