# How does one get the exact location of imaged features on the surface of Mars?

The image above is from the article "Evidence from the Mars Express High Resolution Stereo Camera for a frozen sea close to Mars' equator".

It shows 3 flooded or partially flooded craters 4.8, 2.3 and 1.8 km in diameter, likely within the Cerberus Palus region , but no longitudes and latitudes are mentioned.

Is it possible to get the exact location of these craters and of any other imaged feature on the surface of Mars in general ?

Or is there a database for images of craters on Mars ?

• @uhoh In the case of the three craters, i only know that they are likely in the Cerberus Palus region, and the pictures are taken by the Mars Express High Resolution Stereo Camera so with HiRISE i will likely get nothing. It would be great if there is a zoomable map with very high resolution – Cornelis Jun 16 '18 at 9:30
• google.com/mars – uhoh Jun 16 '18 at 9:35
• Sorry I cleaned up too much. It's here: ode.rsl.wustl.edu/mars Click the Map Search tab. Then also check out the Tools tab, and all of the rest as well. – uhoh Jun 16 '18 at 9:46
• I'm proposing the upper left (larger box) for the first, and the other one the third i.stack.imgur.com/Isndz.jpg The second may be more challenging to identify at all since the topography is so slight. Image from commons.wikimedia.org/wiki/… – uhoh Jun 17 '18 at 20:14
• @uhoh Beautiful image to start the day with ! It's not easy, isn't it , with the different light angles ? But i think you're right, and the second one is almost certain the one in between, looking at the pack-ice below it ! – Cornelis Jun 18 '18 at 8:38

The Planetary Data System (PDS, pds.nasa.gov) contains data (including imagery) collected from all NASA planetary missions, including, of course, Mars. The PDS repositories include an entire archive (they call it a "node") devoted to Cartography and Imaging Sciences (the IMG node).

Visit PDS: The Planetary Data System. Select the Data Search tab. In the "Search based on Target" drop down box, select "Mars System". At the top of this page are listed additional "Search Tools" Links include:

Map-A-Planet at the Cartography Node

PDS Image Atlas at the Cartography Node

One of these may be what you are looking for. The Map a Planet looks very promising! There is a whole "Maps / Products" tab on this page that includes a lot of tools such as a "Planatary Image Locator" and "Planetary Map Index".

Here are some notes that might be helpful:

• Start at the Cartography and Imaging Sciences Node
• In the left had column select "Map-a-Planet"
• On "Map a Planet" use the "Maps / Products" tab to select "Planetary Map Index
• The Planetary Map Index comes up displaying Mercury, first planet from the Sun.
• Note the solar system graphic that allows you to select a planet.
• Note the map that allows you to search the surface features.
• Before selecting MARS from the solar system graphic, use the radio buttons right above to select "Search MRCTR Geologic Maps". I don't know what that means, but it sound relevent and if you leave it at the default "Search all of Astrogeology" the search goes on forever - Not good.
• Now use the solar system graphic to select MARS.
• Mars dramatically zooms in and replaces Mercury. The map graphic now displays Martian surface features. The map is small, but you can zoom in and out and move around. If you know in general where the craters are, you might be able to zoom around and find them.

I note over in the Products list to the right several links that might be helpful:

• Thank you for your answer, but the search system looks rather complex to me. Isn't there just a database for HiRISE images of craters like the LPL catalog ? – Cornelis Jun 16 '18 at 15:50
• Thank you for the added instructions ! Since i'm looking for images of craters, instead of selecting "Map-a-planet" ,i.ve chosen the PILOT button. – Cornelis Jun 18 '18 at 8:57

The article contains several bits of information that will be useful:

Extensive fields of large fractured plate-like features on a horizontal surface are visible near the south end of the High Resolution Stereo Camera (HRSC) imaging strip taken on 19 January 2004 (Fig. 1). This area has previously been covered by NASA high-resolution Mars Orbiter Camera (MOC) imagery at pixel sizes down to 1.8 m (Fig. 2).

Part of an HRSC image of Mars from orbit 32, with a resolution of 13.7 m per pixel, centred at 5.5° north latitude and 150.4° east longitude, showing plate-like deposits with signs of break-up, rotation and lateral movement to the west-southwest in the lower part of the image.

High-resolution MOC images E2100112 and R0900475 of an impact crater seen in Fig. 1a.

We infer that the evidence is consistent with a frozen body of water, with surface pack-ice, around 5º north latitude and 150º east longitude in southern Elysium.

The data from Mars Express is archived here. The ESA Planetary Science Archive has a more searchable archive, where you can find images by date and by instrument. That yields a list of images that might be useful as a starting point. I expect the image metadata will contain the map coordinates of each image.

I downloaded one of the HSRC images (120 MB). In the IMG file, there is a bunch of metadata. You can open the IMG file with a text editor to see them.
FOOTPRINT_POINT_LATITUDE and FOOTPRINT_POINT_LONGITUDE are what you need, but instead of a single long/lat pair you get a series like (52.7632,52.782,52.7906,52.7892,52.7778,52.7565,52.4977,51.8255,51.1656,50.517,49.8838,49.2608,48.6486,48.0525, etc. It looks like this is a strip image of a very large area. So you'll need some more information to map that to the areas in the image.

The MOC images are probably an easier way in, as they cover a smaller area than the HSRC images. So, go to the NASA PDS, enter MOC E2100112 in the search field and the image turns up. No lat/long in the image label, though.

Or you can email the author. His mail address is in this PDF.

• Excellent links, but if i understand it well you can select Mars, the instrument and the time range within which the instrument has taken images of Mars. But i've seen no information about at what place on Mars the presented image comes from. LPL shows the places where HiRSE images have been taken on an interactive Google map, that,s a lot more user friendly.But i think this is the best that we can get. Thank you again, i will email the author ! – Cornelis Jun 16 '18 at 17:24