The Martian atmosphere is very thin compared to that of the Earth. This provides a unique view of the Universe largely unaffected by atmospheric contamination effects, such as astronomical seeing (turbulence) or absorption. For an astronomer, Mars therefore offers a unique window into the night sky. During the Hypatia I mission, we exploited the remote and arid conditions of the Mars Desert Research Station (MDRS) to simulate this experience, capturing high-resolution color images of deep-sky objects with the MDRS MLC-RCOS16 Robotic telescope. This instrument allowed us to produce “RGBLHa” images –that is, composite images resulting from combining standard color data (in the Red, Green, and Blue filters) with Luminance and Hydrogen-Alpha narrowband observations, which reveal structural details often invisible to the naked eye. Over the course of the mission, we imaged a diverse catalog of sources, such as nebulae, spiral galaxies, or supernova remnants. This project had two primary goals: to test robotic observation procedures in preparation for future Mars exploration missions, and to create beautiful images of the Universe to share them with the public back on “Earth.”
As future astronauts learn to live and work on the Red Planet, documenting the night sky will play an important role for research and outreach purposes. This project focused on performing astrophotography of deep-sky objects, exploiting the dark and dry skies of the Utah desert as a proxy for the Martian surface. Beyond its technical objectives, our ultimate goal was to inspire people on “Earth” with the beauty and wonders of the cosmos.
To conduct our observations, we used the MDRS MLC-RCOS16, a 16-inch robotic telescope equipped with a high-sensitivity CCD camera. To maximise the scientific return of our observations, we employed a combination of photometric filters using the RGBLHa technique. This method involves capturing separate exposures for the Red, Green, and Blue (RGB) channels, the Luminance (L) filter for maximum contrast, and the Hydrogen-Alpha (Ha) filter for more narrowband observations. The addition of the H-alpha data was crucial to observe ionized hydrogen gas structures, which are often invisible to the naked eye but appear as bright red regions in objects like planetary nebulae. After acquiring observations in each filter, we used dedicated astronomical software packages to stack the layers, creating composite images that combined natural colors with highly detailed structural features.
During a Martian mission, telescope time may be a precious resource. Recognizing this limitation, we designed a protocol to identify the best targets for observation. In short, we selected objects based on their visibility conditions (e.g. rise, transit, and set times), ensuring they were high in the sky to minimize atmospheric turbulence.. We also filtered targets by celestial coordinates to match the telescope’s observable window, and ranked them based on their photometric properties, prioritizing objects with an apparent visual magnitude brighter than 10-15. Finally, we considered their aesthetic potential and angular size, choosing objects that would fit well within the telescope’s field of view to generate images suitable for science outreach.
Over the course of our MDRS mission, we acquired data for a diverse catalog of deep-sky objects, including emission and reflection nebulae, where the H-alpha filter revealed the most promient features. Notable targets were the Crescent Nebula (NGC 6888), a cosmic bubble created by a massive Wolf-Rayet star, and the Dumbbell Nebula (NGC 6853). We also looked beyond our Milky Way to image distant spiral galaxies, using the Luminance filter to resolve faint spiral arms in objects such as the Sunflower Galaxy (NGC 5055), the Little Pinwheel (NGC 3184), and the interacting galaxies NGC 4273 and NGC 5371.
This project demonstrated the power of robotic astronomical observations in an analog Martian environment. By building a target selection pipeline and a system to acquire and process the images, we showed how future astronaut crews can document the beauty of the night sky, whether from the deserts of Utah or the deserted plains of Mars.
