NASA’s InSight mission touched down on the Martian surface at the end of November, and less than a month later, deployed its Seismic Experiment for Interior Structure (SEIS) seismometer instrument in preparation for observing the red planet’s internal mechanisms. But we knew it wasn't ready for science just yet; InSight still needed to take care of some tedious ground-leveling and then shield the seismometer instrument from the surrounding elements.
It has now been just over a month since InSight first positioned SEIS in its permanent home on Mars, and according to one of NASA’s latest public statements, the lander has been somewhat busy for the last several weeks. Not only has InSight been working around the clock to adjust the seismometer’s tilt on the Martian terrain, but it just recently encased the seismometer inside of its specialized Wind and Thermal Shield.
Image Credit: NASA/JPL-Caltech
Just as the name implies, the Wind and Thermal Shield is designed to keep the SEIS instrument sealed away from wind interference and temperature changes. Even the slightest amount of wind interference can introduce false positives when investigating Mars’ internal vibrations, and rapid temperature changes are just as harmful to the collection of accurate scientific data.
SEIS particularly sensitive to thermal oscillation, such as what transpires as day turns into night, and vice-versa, and InSight’s landing site just so happens to exhibit unstable temperatures throughout the day. According to NASA, the surrounding temperature fluctuates by as much as 170 degrees Fahrenheit from day to night, a difference that is significant enough to impact the metal springs and components that SEIS uses to capture measurements.
"Temperature is one of our biggest bugaboos," elucidated Bruce Banerdt, the InSight mission’s principal investigator at JPL. "Think of the shield as putting a cozy over your food on a table. It keeps SEIS from warming up too much during the day or cooling off too much at night. In general, we want to keep the temperature as steady as possible."
Earth-based seismometers are often buried underground to protect against wind and thermal interference, but InSight isn’t equipped to put SEIS below the Martian surface. Instead, the Wind and Thermal Shield provides an above-ground equivalent to being buried, and integrated software corrects any deviations before they ever reach NASA scientists.
With SEIS now carefully deployed on the Martian surface, it will soon be ready to begin collecting scientific data to help scientists learn more about Mars' mysterious past. Meanwhile, the InSight lander will prepare to deploy its heat flow probe, a specialized device that will be placed underground to measure the planet’s internal temperature.
It should be interesting to see what the InSight mission turns up, especially given all the hype surrounding Mars, its formation, and its part in the modern solar system.