“What's shaking Mars? An overview of NASA's InSight mission” - Dr Anna Horleston - 21st May 2025

One of the largest, if not the largest audience of recent times at Wycombe Astronomical Society,

enjoyed this excellent, entertaining and approachable lecture by Dr Anna Horleston from Bristol

University.

Dr Horleston is a UK Space Agency Fellow in Planetary Seismology whose interests lie in seismic

instrumentation, network management and data interpretation. After more than a decade of Earth-

based work she turned her sights off-world and joined the science team for NASA's InSight Mission to

Mars (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport).

Involved with the project very early, she witnessed the launch of the rocket in May 2018 (“heard plenty,

saw nothing – it was foggy that day!”}. The mission was looking for tectonic and impact events in order

to determine the structure of Mars and improve our understanding of planetary formation. The lander

arrived safely at Mars in November 2018 and deployed a seismic station on the surface of the planet,

containing both broadband and short period sensors.

Anna Horleston demonstrating a Lego model of the InSight lander

In her lecture she described her work leading the MarsQuake Service, managing day-to-day operations

of the analysis team, detecting and cataloguing the seismicity, and reporting to the wider mission teams.

We all soon became experts in interpreting the graphs showing the seismic events which occurred

during the mission, listening to quite a bit of wind and the odd bump.

Graph showing seismic activity on Mars

Perhaps the most spectacular Mars quake was a Magnitude 4 event towards the end of the mission. Her

team were able to pinpoint the origin of the quake on Mars, a meteor impact, and using photographic

data from an orbiting spacecraft identified the crater formed by the collision.

The mission was scheduled to last about one Martian year but actually was able to continue to well

beyond a second year. The rate limiting step was power, and this was determined by how long the solar

panels could continue to produce electricity. It was Martian dust accumulating on the panels that

brought the mission to an end – no amount of ingenuity could devise a means of shifting it. Despite this,

the mission was a great success and much is now known about the structure and formation of the

planet.

Sandy Giles