Viking 2 Seismic Data Confirmed as Marsquakes
A new analysis bridges 50 years of data to confirm the first Martian seismic detections occurred in 1976.
Updated on Oct. 21, 2026 in Geology
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Researchers have identified a link between two ambiguous seismic signals recorded by the Viking 2 mission in 1976 and the region where the InSight lander later detected extensive seismic activity. This discovery retrospectively confirms that the Viking 2 seismometer, which was mounted on the lander deck, likely captured early evidence of Martian tectonic activity.
Why it matters
Understanding Martian seismology is essential for mapping the planet's internal structure and tectonic history. By reconciling data across the 50-year gap between the Viking and InSight missions, scientists can refine their models of planetary evolution.
The Viking 2 seismometer was mounted on the lander deck, while the InSight lander placed its sensor directly on the Martian ground. This difference in placement explains the ambiguity of the two 1976 records compared to the 1,300 clear events documented between 2018 and 2022.
The players
Viking 2
A 1970s-era NASA lander mission that included the first attempt to monitor seismic activity on the Martian surface.
InSight
A NASA lander mission equipped with specialized instruments to map the interior structure and tectonic activity of Mars.
The details
Researchers performed a comparative analysis by re-examining the 1976 raw data and aligning it with the seismic catalog produced by InSight. While the InSight mission successfully isolated signals by placing a seismometer directly on the soil to minimize interference from the lander's hardware, the Viking 2 sensor was susceptible to noise from the lander deck itself. This reassessment validates the historic 1976 signals as likely seismic activity originating from the same region studied by InSight.
Timeline
1976: Viking 2 recorded two possible marsquakes.
2018-2022: InSight lander operated on the surface of Mars.
The Tech Race
This finding bridges a 50-year gap in planetary science, connecting early, ambiguous datasets to the high-fidelity records of the modern InSight era. It marks a significant shift in how historical mission data is re-evaluated to build a continuous record of Martian geological history.
This research provides planetary scientists and researchers with a more comprehensive, long-term dataset to refine models of Mars's interior. There is no immediate change for the general public, as the data applies to ongoing academic efforts to reconstruct the history of the Red Planet.
The takeaway
This reassessment highlights the value of archiving planetary mission data for future analytical techniques. Scientists will continue to watch for further reinterpretations of legacy space exploration data as sensor technology and modeling capabilities evolve.
Further reading
For more on the study of Martian crustal activity, visit our Geology section.
More information
View the complete academic research study link published in the field journal.
Source note: This article includes information reported by Eos.
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