ASU scientists and engineers building the Europa Thermal Emission Imaging System (E-THEMIS) for NASA’s Europa Clipper recently cleared a major hurdle by capturing the first successful test images, known as of “first light” images, from this complex infrared camera.
E-THEMIS, which is led by Professor Regents Philip Christensen of Arizona State University’s School of Earth and Space Exploration, is an infrared camera designed to map the temperatures of Europa for the mission. These infrared images will help scientists search for clues about Europa’s activity, including regions where liquid water may be near the surface.
E-THEMIS “first light” camera test images were taken from the roof of the Interdisciplinary Science and Technology Building 4 (ISTB4) on the ASU Tempe campus using a clean room laboratory specially designed mobile, which protected the camera from dust, microbes and aerosol particles.
One of the most spectacular test images produced from E-THEMIS is a temperature image taken looking north from the ISTB4. In stunning detail, the image clearly shows Sun Devil Stadium and ASU’s “A” Mountain, among other recognizable ASU landmarks. It is even possible to read details inside the stadium from the E-THEMIS instrument, based on temperature differences detected from around 1.1 km (0.7 miles).
During this test, the E THEMIS team also collected temperature images throughout the afternoon and early evening. When displayed in color, these images reveal how the temperature changes as evening approaches. The red, orange and yellow colors in the images indicate warmer temperatures due to the heat and infrared radiation emitted. Dark purples and blues indicate cooler temperatures, with less heat and infrared radiation emitted.
While temperatures are approximations during this testing phase, the progression of cooler colors (purples and blues) from afternoon to evening in all three images, acquired at 12:40 p.m. (top), 4:40 p.m. (middle) , and 6:20 a.m. after sunset (bottom), illustrate how the infrared camera detected surface temperatures changing from warmer in the afternoon to cooler after sunset.
With this successful “first light” test of E-THEMIS, the next step for the team is to begin environmental testing to ensure that E-THEMIS will survive launch and perform as designed in space.