Space discoveries can be pretty sweet, in more ways than one.
US space agency NASA has, for the very first time, captured thermal images of Martian moon Phobos during a full moon phase using its Mars Odyssey orbiter, with the space rock looking uncannily like rainbow-coloured jawbreaker candy.
According to an article by NASA published on May 10, each colour in the enigmatic image is a representation of a temperature range detected by the robotic spacecraft’s built-in infrared camera THEMIS (Thermal Emission Imaging System). As Phobos orbits Mars every seven hours, THEMIS picks up changes in surface temperature, which is also dependent on the the moon’s textures and mineral composition.
Jeffrey Plaut, Odyssey project scientist at NASA’s Jet Propulsion Laboratory, explained that the image captured on April 24 could be likened to a “temperature bullseye”, with the moon being warmest in the middle and gradually becoming cooler towards the periphery.
“Each Phobos observation is done from a slightly different angle or time of day, providing a new kind of data,” said Plaut.
To obtain the photo, NASA noted that THEMIS had to aim towards Phobos dead-on, with the Sun behind the Odyssey spacecraft.
Touted as NASA’s longest-lived Mars mission, Odyssey has been studying the larger of Mars’ two moons since September 2017. However, it was not until these latest observations that scientists finally had a leg-up in understanding what materials make up Phobos, NASA added.
Full moon views are apparently better for studying material composition while half-moon views are more suited for examining surface textures, according to the agency.
THEMIS co-investigator and senior research scientist at the Space Sciences Institute, Joshua Bandfield, elaborated: “With the half-moon views, we could see how rough or smooth the surface is and how it’s layered. Now we are gathering what minerals are in it, including metals.”
Greater understanding of the abundance of certain metals like iron and nickel, as well as the mixture of other minerals, would allow researchers to better ascertain if Phobos was a captured asteroid or simply a pile of Mars fragments that were ejected into space by a giant impact on the planet.
The recent findings do not definitively spell out Phobos’ mysterious origins however, as Odyssey continues to collect data on a moon that scientists currently have very little knowledge of, added Bandfield.
Nonetheless, the dream of understanding Phobos in greater detail and one day walking on its surface has not yet been lost among the stars as human exploration of the moon has been a topic of discussion in the space community and a Japanese sample-return mission to Phobos has been scheduled for launch in the 2020s.
“By studying the surface features, we’re learning where the rockiest spots on Phobos are and where the fine, fluffy dust is. Identifying landing hazards and understanding the space environment could help future missions to land on the surface,” said Bandfield.