A Different View of ‘Inca City’
We see high resolution non-map projected color mosaic images of the Martian South Pole from HiRISE, but with the Context Camera (On Planet Four: Terrains we show the diced up CTX images), you can get a wide view perspective. This is the main drive of Planet Four: Terrains, to use the wide-field Context Camera (CTX) images to find new areas of interest that we can then explore and study in detail.
On the original Planet Four, we’ve spent a lot of time over the past two years focusing on the region informally known as ‘Inca City.’ With CTX can you can get a bird’s eye view of Inca City and its structure. Check out the image below. You’ll notice the unique pattern of interconnecting rectilinear ridges that the region is known for.
You can view the full resolution version of this image here
A quick update on the first paper. We’re getting closer to having the final clustering procedure nailed down. Once we’ve got that, we can make the final catalog of markings from Season 2 and Season 3 from the millions of classifications we have gathered over the past few years. While Michael has been working on that, I’ve been working on some of the other tables we need to include for the paper. We know what we’ve done and have good knowledge of the HiRISE data, but we need to make sure it’s clear in the paper so that any researcher or reader has all the information needed to use the catalog of fans and blotches we’re generating thanks to your clicks. To do that we’re going to put in a table that summarizes all the relevant info about the HiIRSE observations from Seasons 2 and Season 3.
The easiest way I found to do this is to grab this information from the headers of the reduced single HiRISE images non-map projected images with the spacecraft pointing information that we created from the raw HiRISE observations. The HiRISE team reduction pipeline produces the three color band mosaics that we dice up and show on http://www.planetfour.org but since they don’t include the spacecraft information we had to build a single filter version ourselves where we added a few steps to the process that would allow the information needed to get the location on the South pole and the spacecraft information into the image headers. This is what Chuhong worked on last summer.
So I took a script written by Gauri adapted from Chuhong’s code to get the other relevant info like imaging scale, north azimuth, solar longitude from the single filter image headers and stick it in a mysql (a database interface language/setup) table.Then I spent a bit of time writing a code to read the table I created and output it in the format needed for the paper. We’re writing the paper in a format known as LaTeX. I spent an afternoon getting the format correct so that table file would compile. You can glimpse part of the results (the first few lines of the multi-page table) below. I still need to reduce the number of decimal places outputted in certain columns, but the basic information is there. We’ll be including a version of this table in the paper text or supplementary material.
Boulders and a Planet Four Summer
Today we have the last post from Gauri Sharma who is spent her summer working on Planet Four as part of the ASIAA Summer Student Program. Gauri gave a talk at the end of August detailing her work with boulders and developing a pipeline to find the same position in one Planet Four image in others shown on the site. Below Gauri presents her talk slides and her project. Thanks Gauri for all your help this Summer!
I am gonna introduce you some of the features found on Mars’ South Pole and tools used to study these features. I will also tell quick logical science behind those features according my research in these last two months.
This slide tells you how Mars similar and differ from the Earth.
During the winter on South pole a, CO2 ice slab forms over the pole is nearly translucent and ~1m thick. When the ice slab forms, it comprises of frozen carbon dioxide and dust and dirt from the atmosphere. Below the ice sheet is layer of dust and dirt.
When the spring comes sunlight penetrates the CO2 ice slab, and the base of the ice cap gets heated. The temperature of the ice at the base increases causes CO2 sublimation. Sublimation of CO2 creates a trapped pressurized gas bubble beneath the ice layers, These beneath pressurized gas bubbles continuously pushes the upper layers of ice and at one point ice slabs get crack and pressurized gases vent out. A jet like eruption or geyser takes place. It is thought that material (dirt and dust) from below the ice sheet which has been taken by pressurized gas is brought up the surface of the ice sheet and is blown by the surface wind into a fan shape.
It is prediction, just after eruption Geysers supposed to look like this.
When there is enough wind on surface to blown the geysers material fans appears on surface and surface looks like fig1.
If wind is not much effective or not blown then geysers material deposits near the geyser source and a black spot appears on surface called blotches (shown in fig2).
Also during the spring and summer when the geysers are active, the trapped carbon dioxide gas before it breaks out from under the ice sheet is though to slowly remove material and carve channels in the dirt surface. In the mid summer when CO2 fully get vaporized channels are empty cracks. This is annual process of over time produces erosion on surface and channel network looks like spiders (or their official name araneiform).
In every spring and summer season, hundreds of thousands of fans wax and wanes on the Martian South Pole. These features have been captured by then HiRISE camera. HiRISE camera is onboard on Mars reconnaissance orbiter since 2005.
These are the sample images captured by HiRISE camera.
During analyzing of these images, scientists found difficulties, Automated computer routines have not been able to accurately identify and outline the individual feature. But scientists thought a human eye eventually can distinguish and outline these features and shape them. So, A group of scientists created Planet four website purposefully for research on Mars by public help.
This is how, Planet Four website looks like. Working with Planet Four is very easy, just sign up in Planet Four website and take in part of classify shapes on surface. Before getting started they provides a short intro to let you know “How to mark, and useful tools to classify features”. Volunteer classification are collected together and researchers combines these classifications (markings), and they found these markings produces an extremely reliable, fruitful results about features founds on Mars surface.
In slide 10, we seen Planet four images looks different from real images taken by HiRISE camera. Since HiRISE image is huge in size. So for proper analysis and accurate outlining Planet Four team made sub images of HiRISE images and kept them in Planet Four website, we call them tiles.
For my project Planet Four was one of the most important tool. I use Planet Four tiles to examine boulders. Boulders are one of the more interesting objects on Mars surface, and in the South Pole regions monitored by HiRISE only one area seems to have boulders. This region has been dubbed ‘Inca City.’ The boulders in Inca City are likely impact produced. Boulders are Interesting because we think they can help be a heat source of geysers formation. I am looking at how fans are associated with boulders more often than not and has been captured by HiRISE. I studied how surrounding of boulders changes time by time, are they really takes part as the source of geyser formation”.
I chooses some 35 tiles those contains BOULDERS and marked all BOULDERS (shown in fig2). After marking Planet Four provides a makings csv file. That contain your marked BOULDER x and y position and corresponding tile name.
To analysis surrounding of BOULDERS over a time, I need to search over the HiRISE 5year database with the help of markings csv received by Planet Four. Since HiRISE database contain more than 1 lacks tiles. Doing search manually and find useful data and then calculate information, collect belonging files and group them for looking yearly changes seems terrible.
So for this purpose I created a pipeline that can do all this in seconds. This is a very powerful pipeline that Planet Four team doesn’t have before me.
These are the results of my pipelines.
Images in blue box clearly shows, During a season as the month changes surrounding of boulders changes (fans wax and wanes) boulders gets covered with fans material and in next season again boulder start visible.,,,
Spiders in the South Polar Layered Terrain
Previously I talked about the South Polar Layered Deposits (SPLD) that you’ve probably seen in some of the images you’re reviewing on Planet Four: Terrains. Last week on Talk, I learned something new. Volunteer Ray noticed this image:
I thought it was pretty neat to see spiders directly carved into into some of the bands of the SPLD. According to the rest of the science team, this can be a frequent experience, and they’ve seen it before. This was my first time encountering that, so I thought I’d share.Thanks Ray for spotting this.
Spider formation is caused by carbon dioxide gas trapped underneath a sublimated ice sheet during the Spring and Summer on the south pole of Mars. Eventually the gas breaks escapes through the ice sheet creating geysers but in the process it also exploits weaknesses in the surface regolith creating spiders. For some reason it appears those sections of the SPLD are weaker.
You can find more finds like this by classifying CTX (Context Camera) images of Mars’ south pole at http://terrains.planetfour.org
New Data Live – Giza Season 1
Thanks to your help making the push to classify images of Ithaca Season 1 to make room for new data, we have mixed in new data live to the remaining Ithaca images we’re showing on the site. We added Season 1 images from a new area of the South Pole nicknamed ‘Giza.’ These images have never been reviewed in such detail before. With your help we can identify and map all the season fans and blotches.
Here’s what Candy Hansen, principal investigator (PI) of Planet Four had to say about Giza:
Giza is an important region for us to study for several reasons. The study of weather in the polar region benefits by having samples from numerous locations – and Giza is distant enough from the others that you’ve been working on (Manhattan, Inca City, and Ithaca) that we will have another good sample for the atmospheric models. The fans also show an interesting evolution (take a look at this animation) that will help us to understand how particles sink into the ice. We may end up with a better understanding of what causes the bright fans to form. Finally, the channels here are a bit wider than elsewhere – are they older or is the ground more easily eroded?
With your help we are pondering these puzzles! Classify images of Giza at http://www.planetfour.org