Apollo Landing Sites imaged by ISRO
High Resolution Images of the Apollo Landing Sites
Below I explain the steps I followed to process the raw data from the Indian Space Research Organization's (ISRO). The images that I processed have been widely shared on social media and in the news.
PetaPixel: May 4, 2024 "Conspiracy Theorists, Look at These Photos of Apollo Modules on the Moon"
PetaPixel: July 24, 2024 "Which Country Captured the Best Photo of the Apollo 11 Landing Site?"
Background:
Indian Space Research Organization's (ISRO) Chandrayaan2 Orbiter entered lunar orbit in August 2019 & took high resolution pictures of our Moon, including NASA's Apollo 11 and 12 landing sites using the onboard OHRC (Orbiter High Resolution Camera) while at an altitude of about 100km. The OHRC has a resolution of 0.32m/pixel.
From https://www.isro.gov.in/Chandrayaan2_science.html:
"OHRC provides high-resolution images of the landing site which ensure the Lander’s safe touchdown by detecting any craters or boulders, prior to separation. The images it captures, taken from two different look angles, serve dual purposes. First, these images are used to generate DEMs (Digital Elevation Models) of the landing site. Second, they are used for scientific research after its initial role in the landing phase. OHRC’s images can capture the same area on the lunar surface from two different orbits. The coverage area in this case is of 12 km x 3 km with ground resolution of 0.32 m. OHRC is an optical camera system based on Time Delay Integration (TDI) imaging sensors with 12000 detectors. It has 4 TDI settings and 7 different integration times."
Further below the Apollo 11/12 images, I included instructions for how to find and download ISRO's imagery data for yourself.
Additional Apollo landing site resources:
Apollo 12 Landing Site: https://svs.gsfc.nasa.gov/4767
Apollo 11 (ISRO data from 2021-04-02)
Apollo 11 Lunar Module Descent Stage, crop of raw photo taken by ISRO's Chandrayaan2 Orbiter on 2021-04-02. Photoshop Camera Raw Filter adjustments I made on this image: Exposure (+2.25), Highlights (-100)
Apollo 11 Lunar Module Descent Stage, crop of raw photo taken by ISRO's Chandrayaan2 Orbiter on 2021-04-02. No image adjustments.
Apollo 11 Lunar Module Descent Stage: aninated gif image I created while zooming into raw photo taken by ISRO's Chandrayaan2 Orbiter on 2021-04-02. (PDS4 Viewer)
Apollo 12 (ISRO data from 2021-04-05)
Apollo 12 Lunar Module Descent Stage, crop of raw photo taken by ISRO's Chandrayaan2 Orbiter on 2021-04-05. Photoshop Camera Raw Filter adjustments I made on this image: Exposure (+2.25), Highlights (-100). Bootprints are visible!
Apollo 12 Lunar Module Descent Stage, crop of raw photo taken by ISRO's Chandrayaan2 Orbiter on 2021-04-05. No image adjustments. Bootprints are visible!
Apollo 12 Lunar Module Descent Stage, slightly zoomed-out crop of raw photo taken by ISRO's Chandrayaan2 Orbiter on 2021-04-05. No image adjustments.
Apollo 12 Lunar Module Descent Stage: aninated gif image I created while zooming into raw photo taken by ISRO's Chandrayaan2 Orbiter on 2021-04-05. (PDS4 Viewer)
Instructions for how to download this imagery from ISRO:
Step 1: Create a free account at ISRO's Pradan Website: https://pradan.issdc.gov.in/ch2/
Step 2: Once logged in, you will see this menu- Click the box below "Optical High Resolution Camera"
Step 3: Filter data to find these dates (between 2021-04-02 and 2021-04-06)
Apollo 11: ch2_ohr_ncp_20210402T0546284043_d_img_d18.zip
Apollo 12: ch2_ohr_ncp_20210405T1606536730_d_img_d18.zip
Step 4: Save and extract the .zip files to their own folders.
Step 5: Download PDS4 Viewer to open the image data at https://sbnwiki.astro.umd.edu/wiki/PDS4_Viewer
Step 6: Using PDS4 Viewer, open the XML file in the following folder structure:
\ch2_ohr_ncp_20210402T0546284043_d_img_d18\data\calibrated\20210402\ch2_ohr_ncp_20210402T0546284043_d_img_d18.xml
Step 7: Click "Image" as seen below.
The image file is HUGE! It covers an area 12km long by 3km wide, which ends up being 78,175 pixels by 12,000 pixels. You'll need a computer with a lot of memory to work with this file, panning and zooming.
I had to do the hard work: finding the lunar modules in this huge image! While viewing the files named above with PDS4, the Apollo Lunar Module site positions in approximate pixel coordinates are as follows:
Apollo 11: 6246 x 46636
Apollo 12: 9080 x 56400