By Kris Osborn - Warrior Maven
Jupiter’s Europa moon is known to be covered with ice and exist at temperatures as cold as -350 degrees Fahrenheit, yet it is believed there is a vast liquid water ocean beneath the ice...and ocean which could contain the first known sign of life beyond Earth.
Under contract to Arizona State University and NASA’s Jet Propulsion Laboratory, Raytheon Intelligence & Space is collaborating on a soon-to-be-launched Europa Clipper spacecraft tasked with using Raytheon-engineered next-generation infrared detector to search for warmer temperatures emerging from warm water beneath the extremely cold ice.
“One of NASA’s major goals is to look for habitable environments, which need water. There are scientific advances with infrared imaging. Every object emits energy in the infrared and the warmer it is the more energy it emits. One thing you get from infrared observations is temperature, and using this principle the key goal of the camera is to map the temperature of the surface of the moon. The ocean beneath the ice on the moon is moving and churning and where that warm water is getting close to the surface, it will warm up the ice and we will see it,” Phil Christensen, Regents Professor at Arizona State University.
The instrument called E-THEMIS for Europa Thermal Emission Imaging System, uses high-fidelity advanced infrared imaging of Europa's atmosphere, water and ice. The sensor, according to Raytheon data, will use uncooled, microbolometer technology to detect infrared wavelengths from heat sources and develop that data into HD-quality imagery.
Future proposed exploration could involve penetrating the ice, as explained by Christensen and Raytheon Senior Engineering Fellow Paolo Masini. The E-THEMIS will help this goal by mapping the surface temperatures. “Where the ice is the warmest the liquid water is closest to the surface and that is where potential future missions could land and put your submersible in the ocean on Europa” Christensen added about future exploration.
The Raytheon and ASU built THEMIS camera performed a similar role at Mars aboard NASA’s 2001 Mars Odyssey orbiter, which has mapped out landing sites for most of the previous Mars rovers, and has been fundamental to NASA’s long standing space mission. As of April 7, 2021 Mars Odyssey reached its 20-year launch anniversary. NASA’s Jet Propulsion Laboratory in Southern California leads the Odyssey mission, while ASU built and operates THEMIS for the mission.
Masini explained some of the Raytheon innovations which inform E-THEMIS draw upon its history of engineering thermal sensors for defense systems and technology. Unlike light that is visible to the human eye, infrared images sense emissive thermal energy that is radiated from the surface of Europa.
“We can put different infrared filters in front of the microbolometer detectors and make infrared images. Those images are basically a mineral map of the surface, as different minerals form in different environments,” Christensen said. Christensen went on to say e-THEMIS can be used to map the presence of different minerals.
Infrared energy, while unseen to the human eye, can be used to make elaborate maps of different minerals on the surface of Europa as well as indicate where the warmer parts of the ice might be.
“Our eyes are sensitive to a narrow part of the spectrum which is visible light. There are lots of other wavelengths of light and infrared is one of them. A strawberry is red because it is reflecting the red light and absorbing the rest,” he explained.
“Our job is to look for warm spots in the ice. Where the ice is warm, that is where a potential future Europa mission could land. The warmest places on the surface of the ice is where we should land,” Christensen explained.
“Scientists calculate that heat from tidal flexing causes the ocean to remain liquid and drives ice-shell movements similar to plate tectonics, cycling chemicals from the surface into the ocean below,” an essay from the ASU-affiliated Christensen Research Group states.
Raytheon’s work on E-THEMIS dates back to earlier Mars orbiters and rovers from 1996 and 2001. The current E-THEMIS represents the culmination of work to advance and build upon technology pioneered by Raytheon and ASU to fly on NASA’s Mars Global Surveyor mission.
“Of the first indications that water existed on Mars was a direct result of the TES instrument on Mars Global Surveyor because they were able to detect a specific mineral hematite that can only be formed in the presence of liquid water,” Masini said. This detection from orbit was later confirmed by the Mini-TES instrument on the Mars Opportunity rover, confirming that billions of years ago, liquid water existed on Mars.
An interesting essay in Astronomy.com catalogues the trajectory and initial intent of THEMIS-driven sensing through the launch of Odyssey in 2001. Odyssey, which was equipped with THEMIS infrared sensors, discovered some of the first evidence of subsurface water ice on Mars.
“Odyssey arrived at Mars on October 24, 2001, with the goal of investigating the martian environment. The spacecraft was designed to map the planet’s chemical and mineralogical makeup as a step toward understanding the role water played in shaping the environment, both past and present,” the essay writes.
Masini explained the history of Raytheon’s involvement with Odyssey and said data from its mission still informs current work. “Part of Odyssey’s charter was to map the entire surface of Mars to look for optimal landing sites for future missions. Those missions were successful because the information turned out well, and they are still using data to pick potential landing spots.”
“One of NASA’s major goals is to look for habitable environments, which need water. There are scientific advances with infrared imaging. Every object emits energy in the infrared and the warmer it is the more energy it emits. One thing you get from infrared observations is temperature, and using this principle the key goal of the camera is to map the temperature of the surface of the moon. The ocean beneath the ice on the moon is moving and churning and where that warm water is getting close to the surface, it will warm up the ice and we will see it,” Phil Christensen, Regents Professor at Arizona State University, told Warrior in an interview
Kris Osborn is the defense editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics&Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.