19-05-2025
ASU camera checks temps on Mars, but its real mission is a search for life above Jupiter
It's a long way from Tempe to Jupiter, but a thermal camera built at Arizona State University is on its way. First though, it made a crucial detour at Mars, millions of miles from the quiet lab where it started.
A team of ASU scientists built the camera to measure temperatures in some of the coldest places in the solar system.
The Europa Clipper mission tested its E-THEMIS instrument on March 1 during a Martian practice run before it reaches its final destination in a few years: Jupiter's moon Europa. E-THEMIS is a key instrument for testing the chances for life on Europa.
Phil Christensen, an ASU Regents Professor and principal investigator for E-THEMIS, wanted to take advantage of the Europa Clipper's flyby of Mars to test the instrument.
'We know Mars really well,' Christensen said. 'So I said if we can take measurements from Clipper, we can compare them to what we know about temperature on Mars and check our calibration to make sure we get the temperatures right.'
E-THEMIS uses infrared imaging to test planetary surface temperatures and will measure temperatures on Europa's icy crust. Before Clipper reaches Europa in 2030, Christensen turned to Mars to ensure the technology is accurate.
'It wasn't to learn anything new about Mars,' he said. 'It was to acquire some data that is extraordinarily helpful for us as we get ready for the real work when we get to Europa.'
After launching on Oct. 14, 2024, Europa Clipper is on an odyssey to Europa, Jupiter's icy, fourth-largest moon. It is NASA's first mission to Europa to determine if the moon has conditions suitable to support life.
Clipper will orbit Jupiter when it arrives in 2030, conducting 49 flybys of Europa. ASU's E-THEMIS is one of nine instruments that will collect important data during the mission.
The mission's three main objectives are to determine the thickness of the icy shell, investigate its composition and characterize its geology.
'We're pretty sure underneath Europa's thick ice crust there's a liquid, warm water ocean,' Christensen said. 'If you look at the surface of Europa, it looks like it's fractured. We think that ocean is convecting, kind of like a boiling pot of water.'
As warm water rises and the ocean comes closer to the moon's surface, it pulls the upper icy crust apart.
E-THEMIS will measure temperatures along the icy surface. If temperatures are a few degrees warmer in certain areas, they can confirm that the ocean is closer to the surface and that convective activity is happening.
'In order to say how close those oceans are, I need to know the exact temperatures of those fractures,' Christensen said. 'The warmer they are, the closer the warm water is to the surface. The colder they are, the deeper the ocean is.'
That's where the Mars practice run comes in. E-THEMIS needs to accurately measure surface temperatures to predict the ocean's depth beneath Europa's fractures.
E-THEMIS captured over 1,000 infrared images of Mars in 18 minutes and detected temperature variations to validate the instrument's accuracy. They used data from Mars Odyssey, which also has a THEMIS instrument developed at ASU, which has been operational since 2001.
'We verified it works by looking at Mars, because we have other instruments measuring temperatures on Mars, so we know what the truth is,' he said.
Europa's surface temperatures could hold the key to one of the most compelling scientific questions of modern times: whether life exists beyond Earth.
Researchers believe that beneath the surface of this frozen moon, a massive ocean exists that could contain extraterrestrial life. Christenson hopes Clipper and E-THEMIS will help answer two key questions.
'We know Europa is active and the crust is pulling apart, but we don't know whether that activity happened within the last decade or a few hundred, or thousands of years ago,' he said.
They want to know when Europa was active. If the surface temperatures are cold, then they know Europa's warming may have happened thousands or even millions of years ago.
But if there are warmer spots, they could revisit for further study to discover whether life exists in Europa's ocean.
'Someday, we'd like to land on Europa, drill through the ice, put a submarine down there and find out if there's life in that ocean,' Christensen said.
Scientists need to pinpoint areas where the ice is thinnest, or the warmest places on Europa. Those areas will be ideal for drilling and dropping submarines for further exploration.
While the Europa Clipper mission is led by NASA, a major piece was built in Tempe. ASU developed E-THEMIS in a lab just off University Drive, and now it's headed millions of miles into space to explore one of the most promising places in the solar system for life.
'People are always surprised — they don't realize this kind of work is happening right here,' Christensen said. 'Down the street on the ASU campus, we're building hardware that's going to Jupiter. It's pretty cool.'
Christensen has worked on space missions since he was in college. For him, the thrill of discovery and contributing to something bigger than himself is the real reward.
He hopes ASU will continue contributing to NASA's deep space missions and exploring the solar system.
'One hundred years from now, nobody will remember our names,' he said. 'But they'll remember Europa Clipper. That's the kind of mission that adds to human knowledge.'
Hayleigh Evans writes about extreme weather and related topics for The Arizona Republic and Email her with story tips at
This article originally appeared on Arizona Republic: ASU camera seeks life on Europa, one of Jupiter's moons
