Southern Spring is coming to Mars very soon. May 22nd marks the official start of Spring at the Martian South Pole. We’ve been busy reducing the most recent sets of classifications from Planet Four: Terrains looking for new spider locales to target when the HiRISE and CaSSIS seasonal campaign starts. The CaSSIS camera is a recent addition to Mars, aboard the European ExoMars Trace Gas Orbiter (TGO). It takes slightly higher resolution images than the CTX, whose images we show on the Planet Four: Terrains website. CaSSIS is designed for stereo imaging which is key for measuring depths and heights of features. Also unlike CTX, CaSSIS is equipped with several filters so color images can be made. Even with the addition of CaSSIS, the decade old HiRISE remains the highest resolution imager (~30 cm/pixel) in action around the Red Planet.
The PI of Planet Four: Terrains, Candy Hansen is a member of the HiRISE and CaSSIS science teams , and can ask for images to be potentially taken of the Solar Polar region if we find something interesting worthy of followup observations. We’ve asked for a few additional candidate spider locations (plotted below between -70 and -75 degrees latitude) outside of the South Polar Layered Deposits to be imaged if the observations can be squeezed into these cameras’ packed schedules. If confirmed in the higher resolution images, these will be the furthest spider identifications from the South Pole. Fingers crossed we’ll get some more detailed images of these places over the coming months.
Thanks for all your help. We plan to have new images on the Planet Four: Terrains site by the start of Southern Spring, so stay tuned!
We wanted to give a quick update on the original Planet Four. Michael Aye has been leading the development of the data analysis pipeline. As previously mentioned, we’ve hit a major milestone with completing the fan clustering algorithm for combining your classifications together. We think we’ve now hit that point for finalizing the blotch clustering algorithm.
We think we’ve now got a decent solution for addressing how to cluster very large blotches that take up half the image and very small blotches that are the default blotch circle size. Currently how we’re tackling this is clustering with one linking radius for the center of the blotch markings, and then we run the analysis again using a much larger linking radius. Here’s an example output:
This blotch clustering strategy seems to be a good compromise for our science goals and needs. We’re going to review several more test cases and if all goes well with this step, we will freeze development on the clustering pipeline. That’s one of the last hurdles to applying the pipeline to all of your classifications and dive into what the shapes and sizes and directions of the fans and blotches tell us about the seasonal carbon dioxide jet process and the surface winds in the Martian South Polar region.
Thanks to all your help, we’ve completed the review of the Season 4 observations of Giza, Ithaca, and Macclesfield. We have new observations from Season 1 from a two different areas around the South Pole now uploaded and live on the site. These areas are nicknamed Starfish and Caterpillar for the spider morphology that have been seen in those areas. Caterpillar is much further away from the South Pole than some of the areas you’ve reviewed here before.
It will great to see how the numbers and sizes of fans and blotches in these two areas compare to Manhattan, Macclesfield, Inca City, Ithaca, and Giza. Dive into these new images today at http://www.planetfour.org
Over the past many months you’ve been reviewing Season 1 observations of areas nicknamed Macclesfield, Giza, and Ithaca. We’ve now finished the current set of data live on the site. We’ve recently prepared and uploaded Season 4 observations of Giza, Ithaca, and Macclesfield so that we can see how the carbon dioxide jet and fan formation processes evolve over several Mars years in these areas.
Thanks for all of your help, we couldn’t do this without you. The clustering algorithm to combine all of your markings together is nearly finished. We’re making hopefully the last tweaks and improvements. This means that over the next six months to a year we’ll be able to compare the results from your classifications of these new images to Manhattan and Inca City, where we already have four Mars years of HiRISE images classified on Planet Four.
Dive into these new images today at http://www.planetfour.org
We started Planet Four: Terrains with the main goal of finding new regions to study during the upcoming seasonal processes HiRISE campaign. The idea was to have people scour low resolution Context Camera (CTX) images for terrains indicative of sculpting during the seasonal processes produced by never-ending cycle of carbon dioxide ice being deposited on the surface in the winter and that ice sublimating in the spring and summer. We would then select a portion of those areas for further study with high-resolution imaging with HIRISE. With the varied textures of the Martian surface it would be difficult for a machine to do this task, but the human brain is well suited to this task.
We launched Planet Four: Terrains at the end of June as part of the launch of the Zooniverse’s new citizen science platform and project builder portal. Planet Four: Terrains had little less than a year to review 90 full frame CTX images divided into 20,122 subimages or subjects as their known on the website. With your help, the project was able to get through all 20,122 subjects in time, and even put in more images. Thanks to your classifications and Talk discussions, the science team was able to come up with a list of images and locations for further study. We aim to have the HiRSE camera point at these locations and snap images. Some of these locations will be monitored throughout the Southern spring and summer. Right now these locations have been entered in the HiRISE target database. This means that Planet Four: Terrains has successfully achieved one of its prime goals!
Now, Candy Hansen, PI of the project and head of the seasonal processes campaign with HiRISE, will prioritize our targets with the rest of the regions that the HiRISE team wants to study. The first of these should with any luck get images in the next few months. We’ll keep you updated here on the blog.The final list of targets from Planet Four: Terrains is a mix of locations found on Talk and through the classification interface. We’ll have more details as we get closer to the start of Southern spring (July 5th), but we wanted to share one of the new locales,spotted thanks to the volunteer contributions on Planet Four: Terrains, that will be imaged by HiRISE. This specific region shown above was highlighted on Talk. It was noticed by the science team, and we agree it is an interesting area to look at how spiders develop. We’re interested to see how the seasonal fans and blotches over the coming Martian Southern spring and summer. We’re currently planning a sequence of images at this location. CTX has a resolution of 6-8 meters per pixel. HiRISE has a resolution of 30 centimeters per pixel, so we’ll get to see a lot more detail particularly in the structure of the spider channels than what’s current visible in the CTX image above.
This isn’t the end of the project, we’re really just getting stared. Because of your classifications, we’ve found spiders in interesting and potentially unexpected regions so we’ve decided to keep the project going with new locations to review. Help today at http://terrains.planetfour.org
Dear Citizen Scientists!
Long time no hear from me, sorry guys! Last year I was struggling to manage 4 projects in parallel, but at least one of them is finally funded PlanetFour activity (since last August), yeah!
I’m now down to three projects, with another one almost done, leaving me more time on PlanetFour. Things are progressing slowly, but steadily. To recap, here’s where we are:
We have identified 5 major software pipelines that are required for the full analysis of the PlanetFour data, starting from your markings to results that are on a level that they can be used in a publication or shown at a conference. Four of these pipelines are basically done and stable, with the fifth one existing as a manual prototype but not yet put into a stable chain of code that can run from beginning to end. Figure 1 shows the first four pipelines that are finished.
The need of the fifth pipeline was only discovered recently, when we tried to create the first science plots from PlanetFour data: Some of the HiRISE input data that we use is of such high resolution (almost factor 2 better than the next level down) that the Citizen scientists discover a lot more detail than in the other data. This led to an un-natural jump of marked objects over time, making us wonder for a bit why so late in the polar summer a sudden increase in activity would occur. Until I checked the binning mode of the HiRISE data that was used for those markings. All of the ‘funny data’ were taken in the highest resolution possible (while others for data-transport margins are binned down by a factor of 2 or 4).
So, we now understand that we need to filter and/or sort for the imaging mode that HiRISE was in when the data was taken, which is not a big deal, it just needs to be implemented in a stable fashion instead of trial-and-error code in a Jupyter notebook.
Okay, the other thing that is new: For months we were clustering your markings together using only the x,y base coordinates of fans and the center x,y coordinates of blotches. This simplest approach worked already quite well, but a closer review of the acceptance and rejection rates revealed that some of the more ‘artistically’-motivated markings would survive this reduction scheme and create final average objects that would have seemed to come from nowhere at a quick glance. Take Figure 2 for example:
One can see that the lower left image, the end of the first 3 pipelines, contains some markings that seem to come out of nowhere. They are in fact created by an artistic set of fans visible in the upper middle plot, where three fan markings are put where no visible ground features are, and because the base points of these 3 fans are nicely touching each other, they survive the clustering reduction, as the algorithm thinks it is a group of valid markings. Or, better said, it *thought* so. As I taught it better now, and it includes the direction as a criterion for the clustering as well. As Figure 3 shows, this helps cleaning up the magical fans out of nowhere.
One can see, there’s still some double-blotches visible, but another loop over those remaining ones, checking for close-ness to each other will unify those as well.
One last thing I want to mention is “fnotching”, as some of you might wonder what that actually means. In difficult-to-read terrain or lightning, or when the features on the ground are kinda hard to distinguish between fans and blotches, it happens that the same ground object is marked both as fan and blotch, and both often enough to survive the clustering. We call these chimera objects “fnotches”, glued together from FaNs and blOTCHES. 😉 What we do is looping over objects that survive the clustering, and if a fan and blotch are close to each other, we store how many Citizens have voted for both, create a statistical weight out of that (the ‘fnotch’-value) and store that, too, with the fnotch object. Then, at a later point, depending on the demands of certainty, we can ‘cut’ on that value, and for example say that we only consider something as a fan if 75% of all Citizens that marked this object have marked it as a fan. That way we can create final object catalogs depending on the science project that the catalog is being used for.
We have just submitted another conference abstract with the most recent updates to the 47th Lunar and Planetary Science conference, and I seriously, seriously want our paper to be submitted until then, so that you all can see what wonderful stuff we created from all your hard work!
Wish us luck and have a Happy 2016 everyone! Or, as the star of one of my favorite video blogs, HealthCare Triage, keeps saying: To the research!
Today marks the third anniversary of Planet Four’s launch. We couldn’t do this without each and every volunteer who has contributed to the project over the past 3 years. To each and every one of you, thank you!
We made this birthday mosaic of Mars (a full glob image taken by one the Viking spacecraft) assembled out of ~16000 Planet Four tiles. If you’re interested in making your own, we used AndreaMosaic
If you have a spare moment, classify an image or the red planet at http://www.planetfour.org. Onward to year 4!
As 2015 winds down, we thought we’d share some of the most favorited Planet Four images of the year. You can view the images below in the slide show or check them out on Talk here.
Happy Holidays and Happy New Year from the Planet Four Team!
(and if you find some spare time before 2016 there are lots of images still in need of review at http://www.planetfour.org)
Since Mariner 9’s pioneering first mission to survey the surface of Mars, several have followed with more advanced equipment able to unveil more detail. This was in a bid to better understand the underlying processes that formed the features of the red planet, including aeolian structures such as sand dunes.
Mariner 9 Mission
Launched in 1971, the Mariner 9 mission had two primary objectives. Firstly, to map 70% of the Martian surface (originally the objective of the failed Mariner 8 mission) and to study temporal changes in the Martian atmosphere and surface. In terms of mapping, the mission exceeded expectations, managing to capture images of almost 100% of the surface. This revealed aeolian features and also large canyons, massive volcanoes and ancient riverbeds.
Despite this success, Mariner 9’s wide and narrow angle telescope cameras could only capture so much detail. The images created had at best a resolution of 1km, and with 5% of the surface this accuracy reduces to 100km. Although this is perfectly adequate to discover large geological features and entire aeolian systems, it is not detailed enough to study dunes in any great depth.
The Viking Missions
NASA’s Viking Mission to Mars was composed of two spacecraft, Viking 1 and Viking 2, each consisting of an Orbiter and a lander. The mission objectives were to capture high-resolution images of the Martian surface, characterise the structure of the atmosphere and surface, and finally to search for signs of life. Launched in 1975, Viking 1 and 2 Orbiter spacecraft orbited Mars at a distance of 300km above the surface for 1400 and 700 rotations respectively, returning images of the entire surface of Mars with a resolution of 150 to 300m. At selected points of interest, this resolution was improved to an impressive 8m.
The results from Viking gave us the most complete view of the Martian surface to date. The Orbiter images confirmed the existence of volcanoes’, canyons and aeolian features as well as discovering large cratered regions and even evidence of surface water once existing. It meant that these features could be studied in greater detail, and specific regions of sand dunes and sand dune types were discovered.
Mars Global Surveyor (MGS)
Launched in 1996, the Mars Global Surveyor spacecraft was NASA’s first mission to Mars in 20 years. It is still the longest serving mission to date, successfully observing the surface for over nine years until November 2006. It was designed to circle in a polar orbit around the planet (travelling over one pole to the other) twelve times a day collecting images from a height of 400km.
The aim of the mission was to contribute to the four main goals of Martian exploration at the time: determine whether life ever existed on Mars, characterise the climate of Mars, characterise the geology of Mars and prepare for human exploration.
To help achieve this, the surveyor spacecraft was fitted with some of the most advanced instrumentation ever sent into space. Part of this payload was the Mars Orbiter Camera (MOC). This camera had two functions; firstly to take a daily wide-angle image of Mars, similar to the weather photographs seen of Earth, in order to study the climate, and secondly to take narrow-angle images to better understand the geological features.
As with the previous two Martian missions, the Global Surveyor was a great success. The landmark discovery was to be the existence of gullies and debris flow features, suggesting that there could be current sources of liquid water on or near the surface of the planet. This wasn’t to be its only achievement however, as it returned images of the surface down to a resolution of 0.5m. The most detailed so far, they provided new information about the physical nature of the windblown material on the Martian surface and showed that the pre-MGS view was much too simple. In addition to bright dust and dark sand, MOC images show evidence of bright sediment that can be transported by saltation (e.g., sand) and dark material that can be transported in suspension.
Mars Odyssey Mission
Part of NASA’s ongoing Mars Exploration Program, the Mars Odyssey spacecraft launched in 2001, and is still observing the planet to this day. As with MGS, its aim again is to contribute to the four main goals of exploration, and to do this five mission objectives have been derived: to globally map the elemental composition of the surface, determine the abundance of hydrogen, to acquire high spatial and spectral resolution images of mineralogy, provide information on the morphology of the surface and to characterise the radiation risk to human explorers.
The Odyssey spacecraft was fitted with three main instruments to help achieve its targets. THEMIS (Thermal Emission Imaging System) is a camera used to identify the mineralogy of the planet, by studying the different heat radiation properties present. GRS (Gamma Ray Spectrometer) for determining the presence of 20 chemical elements on the surface including hydrogen, and finally MARIE (Mars Radiation Environment Experiment) for studying the levels of radiation present.
Although at first glance none of these instruments seem suitable for the study of aeolian features such as sand dunes, the THEMIS camera also surveys the surface through the visible spectrum. The resulting images have a resolution of 18m, and to date the camera has taken over 15,000 20x20km shots. This resolution nicely ‘fills the gap’ between the large-scale images of the Mariner and Viking missions and the very-high resolution images of the MGS instrumentation.
Mars Reconnaissance Orbiter (MRO)
Launched from Cape Canaveral in 2005, the Reconnaissance Orbiter’s main objective is to search for evidence that water persisted on the surface for a length of time. While previous missions have shown that water flowed across the surface, it remains a mystery whether water ever existed long enough to support life.
The MRO spacecraft is one of the most comprehensive missions ever sent to Mars, with a payload of many different types of instrumentation. As well as the numerous spectrometers, radiometers, radars and engineering instruments on board, three cameras have been included to fulfil a variety of objectives. MARCI (Mars Colour Imager) takes large-scale images of the planets atmosphere in order to study clouds and weather patterns. Two other cameras, HiRISE (High Resolution Imaging Science Experiment) and CTX (Context Camera), are able to take images of a much more suitable resolution to study aeolian features in detail.
HiRISE, as the name suggests, takes ultra-high resolution images of the Martian surface in order to reveal details of the geologic structure of canyons, craters and aeolian features. Able to produce results at a 0.5m resolution, it has so far returned some of the most detailed and striking images of the Martian surface ever captured.
CTX was designed to be used in conjunction with HiRISE, providing wide-area views of the areas being studied in order to provide a context for the high-resolution analysis of key areas of the surface. Although predominantly an auxiliary instrument, CTX produces good quality images in its own right, and has currently returned data for over 50% of the planet at a resolution of 6m. Although not matching the detail of HiRISE, they still can still be used to study sand dunes in detail while having a much-improved field of view.
If you have any other questions regarding some of the things you have spotted on Planet Four: Craters, please feel free to ask on Talk, and in the mean time please keep marking on craters.planetfour.org!
The focus of this post will be on the area of the Martian surface that Planet Four: Craters volunteers have been marking craters on, the Cerberus Fossae.
The Cerberus Fossae is a set of west-north-west trending and almost parallel fissures or fractures that cut across the Cerberus plains on Mars. Evidence suggests that the fissures have been formed by faults that pulled the crust apart in the Cerberus region (9°N, 197°W).
Ripples seen at the bottom of the fault are sand blown by the wind. The underlying cause for the faulting was believed to be magma pressure related to the formation of the Elysium volcanic field, located to the northwest. The faults pass through pre-existing features such as hills, indicating that they are a young feature by the standards of those found on the surface.
In fact, this area of Mars has been identified as having the youngest volcanic plains on Mars. Early crater-counting efforts have suggested that the youngest lava surfaces in the area are less than 10 million years old. This is why it is of such interest to future missions to Mars, as a location where seismic activity might still be happening. To help predict the amount of seismic activity to expect, we need your crater markings to make a more accurate estimate of the age of the region.
If you have any other questions regarding some of the things you have spotted on Planet Four: Craters, please feel free to ask on Talk, and in the mean time please keep marking on craters.planetfour.org!