I would like to share with you our new paper that just got published in January volume of Icarus journal.
The most exciting part of this paper is that HiRISE detected some new troughs in Martian polar areas. The troughs were not visible when the HiRISE observed those locations for the first time in Martian Years (MY) 28 and 29. But when we have commanded HiRISE to take repeated observations in MY 30 and 32, we were rewarded with images of new features that you can see in the animated image below.
The troughs are really small: the whole image is less than 200 m across, while the new troughs are only up to 1 m wide. The total length of them reaches 582 m thanks to their multiple branches.
The new troughs, large enough for HiRISE to detect, are created under the current climate condition – and this is really a big deal. They do look much like spiders: they have different tributaries and resemble the dendritic nature of the large spiders. And they are developing. In turn this means that the large spiders might be developing right now as well. We are still waiting to see topographical changes on the large and fully developed spiders, but we know now that the process is able to erode away quite some ground material. For example, the volume of the material that was moved to create the troughs in the image above is 24 m², they were created over 3 MY, meaning, the process moved 8 m² yearly only in this one example.
The erosion rates like this lets us evaluate the age of the large spiders. They take amazing 1.3 thousands Martian years! It is a long time for a human being, but it is really just a blink of an eye for a geological feature.
We are continuing to monitor these locations to check if these troughs will not be erased in the next years. It well may happen because the new spiders are located very close to the dune fields, and moving sand is capable to cover or sand-blast these small topographical features barely in a year.
I once did a very similar search with Mars Orbital Camera (MOC) images. The camera worked on Mars Global Surveyor from 1997 to 2006. It had 2 sub-systems: a wide-angle camera and a narrow angle camera. The narrow angle camera obtained grayscale images with resolution from 1.5 to 12 m per pixel. It was just good enough to resolve larger spiders and fans.
In 2004 I looked through all MOC images that existed at the time and were located south of latitude -75º. I was hunting for spiders. The result is a list of MOC images that feature spiders and it is now being added to Integrated Database of Planetary Features. It will be available as a layer in JMARS system in a couple of months.
You can see Spiders map on Database of Planetary Features.
When we have a catalog of CTX images with spiders created by you, we will also integrate it into this database! Then everyone can easily navigate around different locations of spider terrains.
Dear Mars Explorers,
Today, June 18 at about 6pm UTC Mars completes yet another turn around the Sun and its calendar starts with brand new year 33 at Ls=0°!
HAPPY NEW MARTIAN YEAR EVERYONE!
You might remember that the last New Martian Year was at Earth’s date July 31, 2013. The shift to June 18 is due to the difference of Martian and Earth year length: the Mars year is 687 Earth days, meaning it’s 43 days shorter than 2 Earth years.
New Year on Mars starts with the spring equinox in the northern hemisphere. This means it is fall right now in the southern hemisphere in the areas that you are analyzing. All the ice from previous winter is long gone by now, the surfaces are inactive. The times of darkness become longer and longer and soon come long winter nights. At some locations there will be polar nights, when the Sun stays below the horizon for more than a day. These times are cold and CO2 will start to condense on the surface. First in some record-cold shadowed places and then all over southern polar areas. And it might even snow CO2 flakes!
I leave you with this simulated Martian analemma – the image of the Sun in the Martian sky taken at the same local time during the whole Martian year. Slightly less bright, the simulated Sun is only about two thirds the size as seen from Earth, while the Martian dust, responsible for the reddish sky of Mars, also scatters some blue light around the solar disk. On Earth an analemma is a figure-8, while on Mars it is a tear-drop because of a different relationship between orbit eccentricity and its rotational axis tilt than on Earth (see this excellent blog post by Ethan Siegel explaining analemma details).
Right now the Sun on Mars is near the middle of this teardrop and moving towards the narrower tip. In about 1 Earth year the spring will come to Southern hemisphere and the southern polar activity will start again, new fans and blotches will appear giving us more data to investigate!
Thank you for helping us with this investigation!
Let us celebrate by classifying an image or two! Happy New Year!
It is really-really tough to get funding to do research. You have to have an idea to do something really new and important, something that will be interesting and useful. You need to gather a team that can do it. Then you have to write a proposal to explain your idea and to convince other scientists that this project is worth pursuing. And you’ll be competing with other projects for the limited budget pot. It was even tougher than usual this year for planetary research at NASA: only 14% of all submitted projects got funding.
But we did!
A little project that utilizes the data from Planet Four will be funded by NASA so that we can compare directions of winds mapped by our citizen scientists (via fans, of course!) to the prediction of martian climate models!
This is so very exciting!
We have a great team here and I am convinced this project will be a great success! Thanks NASA and thanks all of our helpers on planet4!
As many of you know, I’m currently a postdoctoral fellow at the Institute of Astronomy & Astrophysics at Academia Sinica in Taiwan. For the past year and half I’ve spent most of my time living and working in Taipei. Right now in China and Taiwan, as well as some other places around globe, people are celebrating the Chinese New Year (often referred to as the Spring Festival ), which is based on the lunar calendar. The celebration lasts in total 15 days, and it’s a time people gather and celebrate with family. Chinese New Year is in full swing, and as I’m writing this I can hear some fireworks being set off in the distance.
As part of the festivities, ASIAA created a New Year’s greeting card. The director of ASIAA asked for images and figures representing the range of research going on at the institute to use on the card. I send in images from Planet Four selected with some help from Planet Four Talk, and the images made the cut. Can you spot the two below?
For those celebrating, we wish you a Happy Chinese New Year and a happy and healthy year of the ram.
I’m a postdoctoral fellow at the Institute of Astronomy & Astrophysics at Academia Sinica (ASIAA) in a Taipei, Taiwan. As part of the 2014 ASIAA Summer Student Program, we’re looking for an undergraduate student to come to Taipei for the summer, from July 1st-August 29th, to work on Planet Four related research. ASIAA operates in English, and all research will be conducted in English. The description of the project can be found here. Details about the Summer Student Program including rules and restrictions can be found here.
Applications are due before March 28th. If you have questions or if you would like to know more, you can contact me via email at mschwamb AT asiaa.sinica.edu.tw
Tomorrow marks the 50th anniversary of the Deep Space Network, the array of radio dishes scattered around the globe tasked with communicating with NASA’s space missions orbiting the Earth and beyond. The Deep Space Network is crucial for sending commands to orbiting missions around Mars like the Mars Reconnaissance Orbiter, which is the home of the HiRISE camera that takes the images we show, and receiving the data these robot explorers take of our Solar System and the stars and galaxies beyond it.
Three stations were established so that there would always be at least one of the dish complexes on the Earth rotating into range for communications with a distant spacecraft. Today the Deep Space Network has dishes in Canberra, Australia; Madrid, Spain; and Goldstone, USA. The stations are separated by ~120 degrees of longitude.
In the Deep Space Network’s first year of operations, it communicated with just three spacecraft. In 1969, the Deep Space Station 46 (DSS46) in Australia captured the video sent of Neil Armstrong’s famous first Moon walk from the surface of Moon and relayed the video to the rest of the world. Fast forward 44 years to the present, and the Deep Space Network is now charged with supporting and communicating with over 30 space-based missions from NASA, ESA, JAXA, and ISRO. The Solar System has indeed become a busier and much explored place. The radio antennas are always on and talking with these multitude of robot explorers.
In honor of the tireless work of the Deep Space Network and its operators, let us all map some fans and blotches on the images taken from orbit around Mars that they have help provide us at http://www.planetfour.org.
Happy Birthday Deep Space Network, and whatever planet you are on, wishing you a Happy Holiday Season from all of us at Planet Four to you.
Dear Mars Explorers,
Today marks the start of a new Martian year. The Planet Four team wishes everyone a very Happy New Year!
That’s right, today July 31 2013 on Mars, Year 31 turns into New 32 Year. As a Martian year, (a complete 668 days around the Sun) is nearly twice longer than the Earth’s, it is a rather special event. Time to celebrate!
The counting of martian years started on April 11, 1955, this was the date of Ls=0 back in that time. Since then the moment when Mars completes its turn around the Sun shifted for us, Earthlings, from April to July. It will continue to shift further, because martian year is close but not precisely equal to 2 terrestrial years. To give you a perspective, Planet4 is 7 months old now, this means, only a bit older than a quarter of a martian year!
In contrast to Earth, New Year comes to Mars when northern hemisphere is in spring, and it is fall in southern hemisphere. For areas that you are analyzing this means rather boring time: all the ices are gone from the surface and the ground stands bare and inactive. But even inactive, the scenery is still very impressive. For the New Year celebration we decided to share with you a glimpse into a very fresh HiRISE image. It was taken only a week ago. Some of you might recall the area you were studying! Now there are only dim reminders of the fans that you are marking for us so efficiently.
Thank you for doing it with us and lets celebrate by classifying an image or two! Happy New Year!
Dear citizen scientists!
Back then I promised to get HiRISE to image this scene again when the ice is gone. The image is now here, very fresh from the production pipeline:
I framed this image exactly the same as the original “topic-starter”. This way everybody can see that we are talking about the same feature, as 2 months ago. The ice cover is not completely gone yet: one can still see small persistent leftovers in some shadowed places, mostly in small channels. But ice has cleared the feature in question. It happened to be a crater with an unusual inner surface. As often it is hard to see if it is a cone or a depression, but we know that the sunlight comes from bottom right-ish and this tells us it is a crater. To see it better, here is the best zoom HiRISE has to offer (appr. 30 cm/pix resolution):
Without the ice the crater floor looks smooth and its sides show very pronounced polygons. The ice in the trenches between these polygons created the illusion of a bright branching “crown” in our original image. And smooth blanketing on one side of the crater had smooth ice cover that tricked people into seeing Dalek or octagonal-based chimney. So sorry that neither of those are real!
When I saw the polygons inside the crater, I decided to ask my more knowledgeable colleague about them. Mike Mellon (from Southwest Research Institute in Boulder, CO) did a lot of research about polygons on Mars and Earth. He had a look at both, old and new, HiRISE images for us:
“I can see that there are loads of eroded polygons in the region. There are large ones with clear evidence of subdivision into smaller forms. Smaller polygons cover nearly all the surface (roughly 3 meters in diameter). In some areas they are clear and in others they are so small and flat they are a little hard to see. They are completely invisible at the old image because of its poor resolution. The polygons inside the crater are on the order of 5 meters with more deeply incised troughs, so they are easier to see. The crater floor looks featureless. I see these same larger polygons in the neighboring pits, the pits that appear arrayed N-S. The larger polygon size in the crater may be caused by sun light on the crater slopes.
The presence of polygons and their sizes are consistent with ice cemented soils about 2-5 meters deep. But it is not easy to interpret the details and especially hard to eliminate the seasonal effects from this discussion, as this location is very close to the polar cap and spider-related processes happens here and there.”
With this we came back to where we have started from: fans and spiders. The image made it to this project because it had them all. Now plus polygons, minus the chimney.
Ever fancied taking a trip to the planet Mars? On Planet Four (http://www.planetfour.org) we’re asking everyone to help us find ‘fans’ on the Martian surface. Your classifications on this site will enable researchers to better understand the climate and surface of Mars. The images you see here are taken using a high-resolution camera in orbit around the Red Planet. We collect together everybody’s markings of objects on these images and average the result. This is a task that computers are not reliable at, but which humans are really good at. By crowdsourcing your efforts, we can produce data that will show us what is happening in these images.
Every winter Mars’ polar region is blanketed by a layer of frozen carbon dioxide (dry ice). In the Martian spring, this temporary polar cap warms back up and rapidly changes directly from ice to gas (a process called sublimation). This produces geyser-like eruptions through weak spots in the polar cap. Dust is trapped in these eruptions and is carried away by the wind where it then falls in a fan shape across the surface nearby – you can see these fans in the images on this page.
Over the winter the seasonal ice layer is transformed to translucent slab ice, which allows sunlight to penetrate to the ground below in the spring. The ground warms up causing the ice to sublimate from the bottom. This results in gas becoming trapped below the ice layer, under increasing pressure. When a crack or a rupture develops the gas flows out the opening. The escaping gas carries along loose material eroded from the ground. The gas and fine material flow up to the top of the ice layer and out into the ambient wind, as shown in the diagram above. The material lands on top of the seasonal ice layer, downwind of the vent, in fan-shaped deposits. After the seasonal ice layer is gone the fans blend back into the surface material and are no longer visible.
This same activity occurs every spring, and slowly erodes channels in the ground. Often the channels are radially organized, thus earning the colloquial name “spiders”, and more formally “araneiform.” Channels are wide and shallow, generally less than 2 meters deep. In the winter the spiders are visible because the ice is draped over them; in the summer when the terrain is ice-free we see that the spiders are indeed channels carved into the surface, shown in the time-lapse sequence below.
The fans are markers for the wind direction and speed at the time that the gas was escaping and carrying its load of entrained material. Sometimes the vents close and re-open and sometimes the wind changes direction, with the result that we see multiple fans from a single source region. This is all raw data that can be compared to predictions of models for Mars’ atmospheric dynamics, known as global circulation models (GCMs). Sometimes when the conditions are just right the gas will condense into fresh frost particles and form bright fans.
We hope to share more about the background to this project via this blog. Meanwhile, why not go and find some fans? Visit http://www.planetfour.org to start classifying.