A group of amateur and professional astronomers worked together to create what is possibly the highest resolution global map of Mars ever made from images of the Earth.
The images were taken with the 1-meter telescope at the Pic-du-Midi-Observatory in the Pyrenees in France during several nights in October and November.
"The team went on a first mission to the observatory October 7-18, 2020," amateur astrophotographer Thierry Legault told Universe Today. “The weather was not very good (lots of clouds and even snow) and the vision was unsatisfactory. However, we recorded several videos that later helped fill in gaps in the global (360 °) map of Mars. "
Hoping to add additional data to their images, Legault continued to monitor the weather forecast and suggested François Colas (astronomer at the Paris Observatory responsible for the 1-meter Pic-du-Midi telescope) conduct a second mission on October 29th until November 2nd.
"We drove from Paris to the Pyrenees the day before the French delivery (closure due to the pandemic) and took one of the last cable cars," Legault told the summit observatory. "We never got the amazing vision that sometimes happens there, but if we monitor the images constantly, we could get good video for about an hour in the four nights."
With all of the images, the astronomers were able to create the map, which "marks a new milestone for ground-based observatories," Legault said. However, due to the abundance of data, they were also able to create a rotating "planisphere" version as well as a dual version where viewers can use the cross-eye technique to see Mars in 3D:
For best results, use the highest resolution (720p) and the full screen version. When using your phone, turn it sideways (horizontally). Relax your eyes – let them almost cross them, and a third version of Mars should show up in exciting 3D rendering in the center. If that doesn't work, Legault offers two other techniques:
- If you're out of luck with the crossed eyes technique, try joining the two globes in the center of the frame into one. A finger or a thin object in front of your nose can help.
- Try the parallel technique: use two rolls of paper or cardboard held like binoculars. This can help keep each eye on the appropriate globe (left eye for the left globe, right eye for the right globe).
Image processing tools have been key to creating such clear and eye-catching images. According to Legault, Jean-Luc Dauvergne worked incredibly hard on the processing, using Autostakkert (for image selection and stacking) and Winjupos (for combining images taken at different times, and finally the card). During the processing, Dauvergne realized that all images had mapped the entire surface of Mars, which meant that a global map could be created from the data.
The entire team that worked to collect and process images consists of Legault, Colas, Dauvergne, G. Dovillaire, G. Blanchard, B. Gaillard, D. Baratoux and A. Klotz.
The Pic du Midi observatory. Image courtesy Thierry Legault.
The Pic du Midi observatory is located on the Pic du Midi de Bigorre in the French Pyrenees at an altitude of 2,877 meters. Construction of the observatory began in 1878, and the observatory has captured some of the best images of other planets from ground-based telescopes. In the 1960s, NASA funded the installation of the 1-meter telescope to create a photographic lunar atlas and prepare for the Apollo missions.
Thierry Legault (left) and François Colas with the 1-meter Pic du Midi telescope. Image courtesy Thierry Legault.
We would like to thank – as always – Thierry Legault for sharing his knowledge and pictures. You can find more of his great work on his website, as well as on Facebook and Twitter.