The mysterious dark splotches of Mars
A quick holiday fund-raising campaign for Behind the Black!
Scroll down to read this post.
In past years I have managed to avoid asking for donations for Behind the Black during the holiday season. My finances however now compel me to do a short one-week fund-raiser, from November 11 to November 17.
I do not use Twitter for ethical reasons, which I have been told cuts down on traffic to the website. So be it. Furthermore, Facebook has clearly acted in the past two years to limit traffic to Behind the Black, almost certainly for political reasons. So be this as well. Finally, I do not post outside ads, as I have found them annoying to my readers and not that profitable to me.
Therefore, I need to ask for the direct support from my readers. If you like what I do here, please consider contributing, either by making a one-time donation or a monthly subscription, as indicated in the tip jar below.
Regular readers can support Behind The Black with a contribution via paypal:
If Paypal doesn't work for you, you can support Behind The Black directly by sending your donation by check, payable to Robert Zimmerman, to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
Or you could consider purchasing one of my books, as indicated in the boxes scattered throughout the website. My histories of space exploration are award-winning and are aimed for the general public. All are page-turners, and all not only tell the story of the beginning of the human exploration of space, they also help explain why we are where we are today. And I also have a science fiction book available, Pioneer, which tells its own exciting story while trying to predict what life in space will be like two hundred years in the future.
Note that for this week only I am also having a sale on the purchase of the last 20 hardbacks of Leaving Earth. (Click on the link for more information about the book, which was endorsed by Arthur C. Clarke himself!) This award-winning out-of-print book is now only available as an ebook, but I still have a handful of hardbacks available, normally for sale for $70 plus $5 shipping. For this week only you can buy them, personally autographed by me, for $50 plus $5 shipping! Just send me a check, payable to Robert Zimmerman, to the address above, with a note saying that the money is for the Leaving Earth hardback.
Please consider donating. Your help will make it possible for me to continue to be an independent reporter in the field of space, science, technology, and culture.
Cool image time! The image on the right, cropped and reduced in resolution to post here, shows one particular dark splotch in a region with several similar dark areas.
Geologists aren’t quite sure what to make of the dark splotch in the middle of this image, one of several similar dark splotches that extend east and west for over 100 kilometers. From measurements made in infrared, this and other dark splotches have what we call “high thermal inertia,” meaning that it heats up and cools down slowly. Scientists use thermal inertia to assess how rocky, sandy, or dusty a place is. A higher thermal inertia than the surrounding area means it’s less dusty.
The image below the fold shows at full resolution the area indicated by the white box. It provides me no clue as to the cause for the darker color. I think we can speculate all we want, but the truth is that we simply don’t have enough information. We need a closer look, including boots on the ground, to figure this out.
Scroll down to read this post.
In past years I have managed to avoid asking for donations for Behind the Black during the holiday season. My finances however now compel me to do a short one-week fund-raiser, from November 11 to November 17.
I do not use Twitter for ethical reasons, which I have been told cuts down on traffic to the website. So be it. Furthermore, Facebook has clearly acted in the past two years to limit traffic to Behind the Black, almost certainly for political reasons. So be this as well. Finally, I do not post outside ads, as I have found them annoying to my readers and not that profitable to me.
Therefore, I need to ask for the direct support from my readers. If you like what I do here, please consider contributing, either by making a one-time donation or a monthly subscription, as indicated in the tip jar below.
Regular readers can support Behind The Black with a contribution via paypal:
If Paypal doesn't work for you, you can support Behind The Black directly by sending your donation by check, payable to Robert Zimmerman, to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
Or you could consider purchasing one of my books, as indicated in the boxes scattered throughout the website. My histories of space exploration are award-winning and are aimed for the general public. All are page-turners, and all not only tell the story of the beginning of the human exploration of space, they also help explain why we are where we are today. And I also have a science fiction book available, Pioneer, which tells its own exciting story while trying to predict what life in space will be like two hundred years in the future.
Note that for this week only I am also having a sale on the purchase of the last 20 hardbacks of Leaving Earth. (Click on the link for more information about the book, which was endorsed by Arthur C. Clarke himself!) This award-winning out-of-print book is now only available as an ebook, but I still have a handful of hardbacks available, normally for sale for $70 plus $5 shipping. For this week only you can buy them, personally autographed by me, for $50 plus $5 shipping! Just send me a check, payable to Robert Zimmerman, to the address above, with a note saying that the money is for the Leaving Earth hardback.
Please consider donating. Your help will make it possible for me to continue to be an independent reporter in the field of space, science, technology, and culture.
Cool image time! The image on the right, cropped and reduced in resolution to post here, shows one particular dark splotch in a region with several similar dark areas.
Geologists aren’t quite sure what to make of the dark splotch in the middle of this image, one of several similar dark splotches that extend east and west for over 100 kilometers. From measurements made in infrared, this and other dark splotches have what we call “high thermal inertia,” meaning that it heats up and cools down slowly. Scientists use thermal inertia to assess how rocky, sandy, or dusty a place is. A higher thermal inertia than the surrounding area means it’s less dusty.
The image below the fold shows at full resolution the area indicated by the white box. It provides me no clue as to the cause for the darker color. I think we can speculate all we want, but the truth is that we simply don’t have enough information. We need a closer look, including boots on the ground, to figure this out.
The bottom right hand portion of that image looks ‘Glacial’ to me. Wish they could use some penetrating RADAR on it…
Mars always seems to be stranger than the best SF can imagine. But I still think the moon is the 1st place to set up shop.
Unless there’s a smooth depression there, the dark blotch (dark because it consists out of fine dust, I suppose) doesn’t seem to care much about the shape of the landscape. Which seems funny when wind is the natural candidate for making something like this.
Off topic but still on Mars. A lecture about habitability of caves, on Earth and Mars. Sounds like your kind of topic, Robert.
https://www.youtube.com/watch?v=psN7GW9rvn8
Looks like a waste dump to me