On May 5, 2022, the seismometer on the InSight lander recorded a 4.7 magnitude earthquake on the surface of Mars, even though its epicenter was 2,250 km from land. It was one of the largest earthquakes ever recorded on Mars and the largest recorded by the Insight mission. In September, in the first measurement of its kind, the instrument recorded an earthquake on Mars caused by a meteorite impact.
InSight’s seismometer is called the Seismic Experiment for Internal Structure (or SEIS) and has recorded these and over 20 additional earthquakes. Now, an instrument based on the same design will measure ground vibrations on the far side of the Moon, the first seismographs in our neighborhood since the Apollo era.
up to SEIS
Developed by the Institut de Physique du Globe de Paris (IPGP) and the French space agency CNES, the SEIS Very Broadband (VBB) seismometer currently on Mars can detect the tiniest movements down to the much smaller setting of 10 picometers. Consisting of three pendulums set at 120 degrees to each other, SEIS measures the vertical and horizontal vibrations of the Martian surface.
During the development of InSight, a backup model SEIS was established. Now, the VBB in this reserve will be part of the Farside Seismic Suite, which will be deployed to the Moon in 2025 as part of NASA’s Commercial Lunar Payload Services. program. It is one of two seismometers that will work in the impact crater called the Schrödinger basin on the far side of the Moon. The other seismometer will be a short-term sensor.
According to Gabriel Pont, Far Side Seismic Suite According to the project manager at CNES, the instrument on the Moon will have a single broadband pendulum that will measure vertical ground vibrations. The short-term sensor will take measurements in other directions.
The new environment required minimal changes. “We used a backup model of the SEIS instrument. Far Side Seismic Suite The seismometer will be adjusted for lunar gravity. “It will be housed in a vacuum containment box called a Seismobox,” Pont said.
Philippe Lognonné of the IPGP and Dr. Far Side Seismic Suitesaid the single vertical axis sensor will be used with very little change. “Depending on the frequency, this seismometer will be either comparable or up to 10 times better than Apollo seismometers,” Lognonné said.
many firsts
this Far Side Seismic Suite It will mark the first time a seismometer will be placed on the lunar surface since the Apollo missions. It will also be the first time a seismometer will operate on the far side of the Moon.
“Originality Far Side Seismic Suite will be independent of the land owner. This is because it must survive several lunar days and nights, which is not the case for the lander. this Far Side Seismic Suite “Pont will have its own solar panels, antennas to talk to orbiters, and its own thermal controllers.”
According to Pont, one of his main goals Far Side Seismic Suite To determine the seismic activity and impact rate in the region where micro meteorites land. “This could also be useful for future exploration missions, whether manned or deploying a telescope on the far side of the Moon,” Pont said. Said.
“Over a long period of time, the VBB will be able to detect the interaction of seismic waves with a possible deep molten region of the Moon. It’s crucial for understanding how the Moon has evolved since its formation,” Lognonné said.
SEIS’ success on Mars and its selection for its next lunar mission comes after years of research and development. Lognonné recalls that the first proposal for a broadband seismometer at IPGP was adopted in 1993. “Since the mid-1990s, we started development and worked continuously to get it ready for flight. It took us 15 years to be selected for the InSight mission in early 2010,” he said.
Dhananjay Khadilkar is a journalist based in Paris.
