Archive | HiRISE RSS for this section

Where Do the Images Shown on the Planet Four Projects Come From?

The images you review on the Planet Four projects (Planet Four, Planet Four: Terrains, and Planet Four: Ridges) come from two different cameras onboard NASA’s Mars Reconnaissance Orbiter (MRO). MRO has been in orbit around Mars since March 2006. Science operations commenced in November 2006. Nearly 14 years later and MRO has continued to observe and monitor the Red Planet.

Artist Impression of Mars Reconnaissance Orbiter in orbit (Image credit: NASA JPL)

MRO is equipped with several instruments :

  • HiRISE (High Resolution Imaging Science Experiment) – a high-resolution color imager
  • CTX (Context Camera) – grayscale mid-resolution imager
  • MARCI (Mars Color Imager) – color weather imager used to monitor clouds and Martian dust storms
  • CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) – spectrometer that can take composition images of the surface – 2-dimensional maps of the different compositions of the surface
  • MCS (Mars Climate Sounder) – probing the conditions within the Martian atmosphere: temperature, dust, and water vapor concentrations
  • SHARAD (Shallow Radar) – ground-penetrating radar to explore the structure of the Martian subsurface

As MRO orbits Mars, it performs a complex ballet where the different images are taking observations at different times throughout the orbit. The observations are requested by the instrument science teams who are doing a wide variety of science with MRO.

On Planet Four, we use the high resolution color images from HiRISE which can see from orbit surface features down to about the size of your average. HiRISE has a resolution of about 30 cm/pixel. HiRISE is the highest resolution imager sent to another planet in Solar System. In Planet Four: Terrains and Planet Four: Ridges we’re using the grayscale CTX images which covers a wide area but at a lower resolution (6-8 m/pixel) compared to HiRISE. CTX actually provides context for where HiRISE and CRISM are observing and every time these two instrument takes an observaiton, CTX snaps an image as well. HIRISE is so high-resolution that CTX provides the context to tell researchers about what the topography and area around the HiRISE image. If you’ve ever checked out Google Mars visible imagery, you’ve seen some of CTX’s handywork. CTX has image nearly all of the Martian surface several times over.

MRO has now completed over 60,000 orbits around Mars and sent back a whopping 388 terabits of data to Earth. It’s still going strong and HiRISE and CTX are continuing to function. As long as they do, we hope to be able to put those images onto the project sites to continue exploring the current and past climate of Mars.To mark 15 year since the launch of MRO, NASA has put together a great collection of images taken by the spacecraft and its imagers and this video below to mark a decade of MRO science shows some of the striking images the cameras onboard have taken of the Red Planet.

Research Experience for Undergraduates

There is a nice program for undergraduates here in the US that is called REU: Research Experience for Undergraduates.

Within this framework the Planet Four team here in Boulder, CO was fortunate to receive funding support by the United Arabic Emirates for one of these undergraduate positions for this summer.

Working with us was Shahad Badri, and the project we came up with for her was to look at blotch data from Planet Four. Our hypothesis was that it should be relatively straight forward and provide us with insights on jet eruption physics alone, because no wind was involved in depositing the jet deposits.

As usual, the reality turned out to be more complicated than our naive thinking, so we are still digesting the results of plotting blotch area and blotch eccentricities over the time of the Martian year (= Ls = Solar Longitude), but we wanted to show you the nice poster that Shahad came up with at the end of the summer project.

As in any exciting science project, the analysis created more questions than we had before. We will need to juxtapose these results with geometrical parameters of the fans, to see where we maybe have transitions between fans and blotches due to ground winds, shifting deposits around, making blotches look more fan-like.

Thanks to Shahad for her diligent work over this summer!

final poster.png

Full res PDF

Exploring Interannual Variability in Manhattan: New Results and New Images on Planet Four

Today we have a post by Candy Hansen, principal investigator (PI) of Planet Four and Planet Four: Terrains.  Candy also serves as the Deputy Principal Investigator for HiRISE (the camera providing the images of spiders, fans, and blotches seen on the original Planet Four project).  Additionally she is a  member of the science team for the Juno mission to Jupiter. She is responsible for the development and operation of  JunoCam, an outreach camera that involves the public in planning images of Jupiter.

We have discovered something very interesting in the number and size of the fans that show up on the south polar seasonal cap every spring, that you are measuring.  It turns out that in springs following both global and regional type A dust storms we see a lot more fans than normal for that time of year.  This picture compares sub-images from 7 Martian years taken in “Manhattan” at solar longitude 195-197.   The position of Mars in its orbit is the solar longitude (“Ls”), and southern spring begins at Ls 180 when the sun crosses the equator and heads south.   Mars years 29, 30 and 33 have visibly more fans.   There was a global dust storm in Mars Year (MY) 28 that started in early summer.  Intense Type A storms, which are regional and centered at high southern latitudes, took place in MY29 and MY32.  It looks like the spring after these storms have large numbers of seasonal fans.


Although the visual impression is powerful when these images are compared we can go beyond that now, thanks to the Planet Four fan catalog  that your work has populated.  We can quantify the differences. We used the MY29 an MY 30 catalog that we’ve published this year in our first paper, and also newly generated catalogs for Manhattan for MY 28, MY31, MY 32.   Instead of just saying “there are a lot more fans” we can say “there are over twice as many fans” in MY29 and MY30 compared to MY28, 31 and 32.   We do that by querying the catalog – an example is shown below.  The plot below shows numbers of fans as a function of time in the spring and we can compare 5 years at Ls 195.  I had the pleasure of presenting this (your!) work at the 2019 Lunar and Planetary Science conference last week in Houston, Texas.

Manhattan Classic_fan_area_vs_fan_nr_5MY_v3.pngManhattan Classic_fan_nr_vs_ls_5MY_v2.png

To confirm that Type A storms are playing a significant role in the composition of the seasonal ice sheet that produces the carbon dioxide jets that bring up the dust and dirt that create the seasonal fans and blotches, we need to look at the number of seasonal fans and the area covered in MY33.  We only have classifications for Seasons 1-5 of the HiRISE seasonal monitoring campaign (MY28-32). This brings me to my request:  We would really like to have Planet Four measurements for MY33.  We have uploaded the images, so it is ready for you to process.  We would like to thank you in advance for your generosity with your time.   Once those measurements are in we will be ready to write our next paper documenting these findings in a peer-reviewed scientific journal.  As you know we have published one paper already and two more are in progress.  This is a significant result, and we could not have done this without all of you.

Help classify the new images of Manhattan today at



Planet Four Talk at the Division for Planetary Sciences

Greetings from Knoxville, Tennessee. Earlier this morning, I presented our first catalog and early results from comparing the fan directions over two Mars years at the American Astronomical Society’s Division for Planetary Science meeting.  Here’s my slides.





South Polar Locales Comprising the First Planet Four Catalog

The science team is working on ticking off the last things on the todo list before we can submit the first Planet Four paper.  Michael is in the last stages of making edits and changes to the paper draft.  We’re nearly over the finish line. While Michael has been working hard on the manuscript text and catalog files, we’ve  also been iterating on some changes to the figure Anya made that shows all the locations making up the Seasons 2 and 3 monitoring campaign that are part of our fan and blotch catalogs based on your classifications. I thought I would share some of the versions Anya made:


All the locations monitored by HiRISE that were classified by Planet Four volunteers to make the Season 2 and 3 catalog. Credit: G. Portyankina


All the locations monitored by HiRISE that were classified by Planet Four volunteers to make the Season 2 and 3 catalog. A labeled version (for clarity a few regions don’t have their names listed). We note all of these names are unofficial nicknames and are not IAU approved. Credit: G. Portyankina

It’s really exciting to think back to when this project started in 2013 and now see this plot, where I can say we have fan and blotch identifications for HiRISE images taken in Season 2 and 3 Southern Spring/Summer for all of these plotted points.

5 Earth Years of Planet Four

Today we have a post by Dr. Candice (Candy) Hansen, principal investigator (PI) of Planet Four and Planet Four: Terrains. Dr. Hansen also serves as the Deputy Principal Investigator for HiRISE (the camera providing the images of spiders, fans, and blotches seen on the site). She is also a Co-Investigator on the Ultraviolet Imaging Spectrograph on the Cassini spacecraft that orbited around Saturn until the end of its mission last year. Additionally she is a  member of the science team for the Juno mission to Jupiter. Dr. Hansen is responsible for the development and operation of  JunoCam, an outreach camera that will involve the public in planning images of Jupiter.

Last week marked the 5th anniversary of Planet Four’s launch. Five years ago,  I was sitting in a meeting only partly paying attention.  I was focused on the brand new Planet Four website – it had just gone live and took off like a rocket.  I kept hitting refresh, enjoying each of the new introductions in the “Hello Everyone!” chat.

Now we have a community.  When I lurk (which I still love to do) I recognize the names – Pete J, wassock, Kitharode, angi60, p.titchin, ….  My heartfelt thanks go to Meg Schwamb for engaging with our citizen scientists on a regular basis!

Five years on you have measured fans and blotches in over 5 million HiRISE image cutouts.  We’ve applied statistical analysis and turned that into a catalog.  We can now query the catalog (where is the longest fan?  Which way is the wind blowing in Manhattan at the beginning of spring?)   We are very close to submitting our first paper describing the catalog with samples of potential results that can be pulled from it.  The second paper is already shaping up with comprehensive results for wind directions throughout spring – these results are the gold we were hoping for when we started this citizen science project.  The vision we had in the beginning is now coming true.

Right now we use models to understand Mars’ meteorology.  In order to test the models we need data – wind markers.  The atmospheric modeling scientists are very excited about seeing our results – results we wouldn’t have without your efforts!  Thank you as always for your generosity with your time!!


Planet Four at the Division for Planetary Sciences Meeting

The American Astronomical Society’s Division for Planetary Sciences meeting was held last week in Provo, Utah. We presented results from Planet Four: Terrains, but it wasn’t the only Planet Four project represented. There was an update on Planet Four. Chase Hatcher attended the meeting ready to talk about Planet Four. Chase is, a student at the University of North Carolina at Chapel Hill and he spent this past summer working in Colorado with Anya and Michael on Planet Four analysis.

Chase presented a poster on his work at DPS as well as some of the other progress on the Planet Four data analysis we’ve made. Thanks Chase for all the hard work and for representing Planet Four. You can find Chase’s poster below.



Planet Four: Terrains at the Division for Planetary Sciences Conferences


Image credit: DPS/AAS/

Greetings from Provo, Utah. I’m here to present science results on Planet Four: Terrains among other things.  The DPS is now trying out a new set of poster presentations using large touch screens, which they are calling iPosters. My abstract was selected for an iPoster. This means you can currently explore view and my iPoster online here. Enjoy!

Finalizing the Planet Four Seasons 2 and 3 Fan and Blotch Catalog

Michael produced these great plots below showing the fan and blotches identified in each subject image showing 6 overlaping subjects. We have overlap to ensure that we don’t miss marking features at the edges of subject images.  We had to cut up the HiRISE images into smaller chunks in order to get the resolution needed  and make the Planet Four website as easy to use as possible.

Each color in the plot below represents a Planet Four subject image. The dashed blue lines are to show the overlap region boundaries and the solid blue lines are the boundaries between the subject images.



These are all from Ithaca where the fans tend to be very wide. It’s a very flat region on the Martian South Polar region, which might have something to do with it. So it’s one of our best cases to look at what we should do about combining the sources from different subjects in the overlap region.

Looking at these plots, we see fan directions aren’t impacted. That although in some cases we have to fans or two blotches on top of each other with different widths and extents, the direction of the source is well represented. By using shapely we’ll be able to deal with this. For the project’s first paper, we’re focused on wind directions so we’re calling the catalog done for now and will do the Shapely stage next for fan and blotch areas and counts.

We can now confidently turn your clicks into wind directions. This is a big milestone for the project. It means we get on to writing the second half of the Planet Four paper, talking about the catalog and what we see for wind directions.  Onwards and upwards!

Planet Four and Shapely

I thought I’d share a figure from last week’s science team call that the science team discussed.  Michael was looking at combining clustered features with Shapely, a Python package for manipulation and analysis of planar geometric objects. Partly this is to investigate whether this could be used to deal with differing clusters in the overlap regions between neighboring subject images and also test out if we can use the software package to easily calculate the total area covered by the seasonal fans and blotches.  Shapely does a good job of merging the blotches together as you can see from the figure below. This definitely looks like a way forward for calculating the total surface area per time of year covered in dark fan material.


Image credit: K-M aye