A decade of changes at the Martian south pole
Click for full image.
The image above, cropped, reduced, and annotated to post here, was released this week by the Mars Reconnaissance Orbiter (MRO) team. It shows the changes that have occurred at one location at the Martian south polar cap in the past decade. As planetary geologist Alfred McEwen wrote,
The south polar residual cap of carbon dioxide ice rapidly changes. This image was planned as an almost exact match to the illumination and viewing angles of a previous one we took in August 2009.
The pits have all expanded and merged, and we can just barely see the patterns in the 2009 image compared to this January 2019 picture. The 2009 image is also brighter and bluer, with more seasonal frost and/or less dust over the surface. These images were both taken in late southern summer, but our 2019 picture is slightly later in the Martian season by about two weeks.
You can get a better idea how much is changed by seeing the full image from which the above small area was cropped.
Click for original image.
Click for original image.
To the right is the 2009 image, reduced, rotated, and annotated by me. The red box indicates the small area covered by the above image. South is to the right. The many circular features probably indicate craters buried below the cap.
Below and to the right is the full 2019 image, rotated and cropped by me to match the 2009 image. The widespread differences are obvious. All of the white smooth areas have shrunk. New spots have appeared in those white areas, also suggesting the existence of buried craters.
The mystery here is that these images were both taken at almost the same moment in the late southern summer, though about five Martian years apart. Why should the white areas have shrunk? We would expect a reduction from winter to summer, but these were both taken in summer. While it would make sense to see changes, with some areas growing and others shrinking, we should expect to see about the same amount of white area.
Instead we see shrinkage only. Why? The only simple solution I can come up with that maybe these images simply don’t cover enough territory to provide us the full picture. The white areas, which are probably either frost or dry ice, have shrunk here, but grown in adjacent areas beyond this image.
Or maybe Mars has too many SUVs, and is now experiencing global warming! Yeah, that’s the answer! Nothing else make sense! The science is now settled. And if you disagree with me you must be a homophobic, white supremacist fascist, racist!
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for full image.
The image above, cropped, reduced, and annotated to post here, was released this week by the Mars Reconnaissance Orbiter (MRO) team. It shows the changes that have occurred at one location at the Martian south polar cap in the past decade. As planetary geologist Alfred McEwen wrote,
The south polar residual cap of carbon dioxide ice rapidly changes. This image was planned as an almost exact match to the illumination and viewing angles of a previous one we took in August 2009.
The pits have all expanded and merged, and we can just barely see the patterns in the 2009 image compared to this January 2019 picture. The 2009 image is also brighter and bluer, with more seasonal frost and/or less dust over the surface. These images were both taken in late southern summer, but our 2019 picture is slightly later in the Martian season by about two weeks.
You can get a better idea how much is changed by seeing the full image from which the above small area was cropped.
Click for original image.
Click for original image.
To the right is the 2009 image, reduced, rotated, and annotated by me. The red box indicates the small area covered by the above image. South is to the right. The many circular features probably indicate craters buried below the cap.
Below and to the right is the full 2019 image, rotated and cropped by me to match the 2009 image. The widespread differences are obvious. All of the white smooth areas have shrunk. New spots have appeared in those white areas, also suggesting the existence of buried craters.
The mystery here is that these images were both taken at almost the same moment in the late southern summer, though about five Martian years apart. Why should the white areas have shrunk? We would expect a reduction from winter to summer, but these were both taken in summer. While it would make sense to see changes, with some areas growing and others shrinking, we should expect to see about the same amount of white area.
Instead we see shrinkage only. Why? The only simple solution I can come up with that maybe these images simply don’t cover enough territory to provide us the full picture. The white areas, which are probably either frost or dry ice, have shrunk here, but grown in adjacent areas beyond this image.
Or maybe Mars has too many SUVs, and is now experiencing global warming! Yeah, that’s the answer! Nothing else make sense! The science is now settled. And if you disagree with me you must be a homophobic, white supremacist fascist, racist!
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The uniformity of the revealed freeze/thaw pattern is interesting. Geomorphologists must have a field day with NASA’s Mars photos. Some images you’ve shared have shown terrain beyond imagining.