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“It was true detective work!”

“It was true detective work!”

In an interview with ETH, that was published today, Domenico looks back on more than three years of work on the InSight mission.

The full interview with a short video can be found here.


Largest Marsquake observed since the beginning of the NASA InSight mission

On 4 May 2022, NASA’s InSight Mars lander detected the largest quake ever observed on another planet: an estimated magnitude 5 event. The largest previously recorded quake on the red planet was a magnitude 4.2 detected on 25 August 2021.

The recent M5 event, labelled S1222a as the event occurred on the Martian day Sol 1,222 of the mission, was detected by a graduate student at ETH Zurich on duty at the time when the signals were analysed on Earth. It was not hard to spot though - the event is so large it has by far the strongest signal since the beginning of the mission, despite the event occurring in a season where almost no marsquakes are observed due to high winds disturbing the signal.

A magnitude 5 quake is a medium-size quake compared to those felt on Earth, but it’s close to the upper limit of what scientists hoped to see on Mars during InSight’s mission. The science team will need to study this new quake further before being able to provide details such as its location, the nature of its source, and what it might tell us about the interior of Mars.

Shortly after recording the event, Insight went into safe mode - where the spacecraft suspends all but the most essential functions to save energy - due on-going issues with low power associated with mounting dust on the solar panels. It is possible that S1222a is one of the very last events Insight will record. With over 1,300 events already catalogued, it is most likely Mars saved the best until last.

InSight is equipped with a highly sensitive seismometer provided by Centre National d’Études Spatiales (CNES) in France, and a digitizer provided by ETH Zurich in Switzerland. The ETH Zurich team in close collaboration with the Swiss Seismological Service  also coordinates Insight’s Marsquake Service that screen the data for seismic energy, characterize marsquakes and curate the marsquake catalogue.


InSight in the annual report of ETH Zurich

InSight in the annual report of ETH Zurich

The Insight mission and its findings were acknowledged in ETH’s annual report 2021.
You can download the report here.


InSights into Mars - virtual lecture with live Q&A session

InSights into Mars - virtual lecture with live Q&A session

In his virtual lecture, Dr. Simon Stähler from the Institute of Geophysics explains the most recent findings of the NASA InSight Mission.
Join him for a live Q&A session on 16 March 2022 at 16:00 CET (15.00 UTC).
Please submit your questions in advance to simon.staehler@erdw.ethz.ch

Date: March 16, 2022
Time: 16.00 - 17.00 CET
Language: English
Organization: focusTerra (contact: info_focusterra@erdw.ethz.ch)


Using ambient noise to uncover three billion years of Mars's past

Using ambient noise to uncover three billion years of Mars's past

There are two ways to find out what lies deep beneath our feet: you can either drill a hole, or you can use seismic waves to create an image of the subsurface. In recent decades, seismologists have developed and improved techniques that use ambient noise to map structures in the near-surface layers down to a depth of several hundred metres. Using technologies tested on Earth, seismologists have now mapped structures on another planet for the very first time. These analyses provided a glimpse into three billion years of Mars's past, as detailed in a study recently published in Nature Communications.

Since NASA's InSight mission landed on Mars in November 2018 and installed a seismometer, the Marsquake Service, led by ETH Zurich and involving the Swiss Seismological Service (SED), has been regularly analysing the recorded seismic data. In addition to identifying numerous marsquakes, researchers used these data to make statements about the structure of the planet's interior. They built a profile of the planet's crust, mantle and core but could not yet reveal much about the near-surface structures. However, shallow subsurface is vital to understanding Mars's geological history.

Rather than using marsquake signals to look into the subsurface, the new study utilises the ambient noise recorded at times without marsquakes. On Earth, such noise is generated by ocean waves, wind and human activity. Over the past few decades, the SED has developed methods to analyse ambient noise. These methods are used to define the structure of the local geology and to determine whether the local subsurface tends to attenuate or amplify seismic waves. This information is crucial for determining a site's earthquake hazard and analysing unstable landslide zones on mountains or in lakes.

On Mars, ambient noise is triggered by the wind, which generates seismic waves when interacting with the planet's surface. Based on analyses of this ambient noise, researchers can now image for the first time the shallow subsurface of Mars and study its geological history at depths ranging from a few dozens to two hundred metres. In contrast to Earth, Mars has never been home to any active plate tectonics. The planet has been shaped by phases of active volcanism that covered large areas with basaltic lava plateaus. The new analyses provide now a detailed image of the subsurface at the InSight landing site and show a top layer of three meters sand (regolith) and loose rock about 20 metres thick that has been fissured by thousands of meteorite impacts. Below are layers of lava flows that covered the planet between 1.7 and 3.6 billion years ago. These lava layers are divided by sediments lying at around 30 to 75 metres deep. The seismic image of the layer-cake geological stratification allows researchers to trace, for the very first time, the most important geological events that have occurred at the InSight landing site on Mars over the last three billion years.

When humans land on Mars one day, they need to know what lies under their feet. The question of whether these near-surface layers contain water is, for example, particularly interesting. The results of this latest study demonstrate that established techniques to investigate Earth are helping to answer such questions on Mars.

Hobiger, M., Hallo, M., Schmelzbach, C. et al. The shallow structure of Mars at the InSight landing site from inversion of ambient vibrations. Nat Commun 12, 6756 (2021).


The anatomy of a planet

The anatomy of a planet

Researchers at ETH Zurich working together with an international team have been able to use seismic data to look inside Mars for the first time. They measured the crust, mantle and core and narrowed down their composition. The three resulting articles are being published together as a cover story in the journal Science.

Since early 2019, researchers have been recording and analysing marsquakes as part of the InSight mission. This relies on a seismometer whose data acquisition and control electronics were developed at ETH Zurich. Using this data, the researchers have now measured the red planet’s crust, mantle and core – data that will help determine the formation and evolution of Mars and, by extension, the entire solar system.

Mars once completely molten

We know that Earth is made up of shells: a thin crust of light, solid rock surrounds a thick mantle of heavy, viscous rock, which in turn envelopes a core consisting mainly of iron and nickel. Terrestrial planets, including Mars, have been assumed to have a similar structure. “Now seismic data has confirmed that Mars presumably was once completely molten before dividing into the crust, mantle and core we see today, but that these are different from Earth’s,” says Amir Khan, a scientist at the Institute of Geophysics at ETH Zurich and at the Physics Institute at the University of Zurich. Together with his ETH colleague Simon Stähler, he analysed data from NASA’s InSight mission, in which ETH Zurich is participating under the leadership of Professor Domenico Giardini.

No plate tectonics on Mars

The researchers have discovered that the Martian crust under the probe’s landing site near the Martian equator is between 15 and 47 kilometres thick. Such a thin crust must contain a relatively high proportion of radioactive elements, which calls into question previous models of the chemical composition of the entire crust.

Beneath the crust comes the mantle with the lithosphere of more solid rock reaching 400–600 kilometres down – twice as deep as on Earth. This could be because there is now only one continental plate on Mars, in contrast to Earth with its seven large mobile plates. “The thick lithosphere fits well with the model of Mars as a ‘one-plate planet’,” Khan concludes.

The measurements also show that the Martian mantle is mineralogically similar to Earth’s upper mantle. “In that sense, the Martian mantle is a simpler version of Earth’s mantle.” But the seismology also reveals differences in chemical composition. The Martian mantle, for example, contains more iron than Earth’s. However, theories as to the complexity of the layering of the Martian mantle also depend on the size of the underlying core – and here, too, the researchers have come to new conclusions. 

The core is liquid and larger than expected

The Martian core has a radius of about 1,840 kilometres, making it a good 200 kilometres larger than had been assumed 15 years ago, when the InSight mission was planned. The researchers were now able to recalculate the size of the core using seismic waves. “Having determined the radius of the core, we can now calculate its density,” Stähler says.

“If the core radius is large, the density of the core must be relatively low,” he explains: “That means the core must contain a large proportion of lighter elements in addition to iron and nickel.” These include sulphur, oxygen, carbon and hydrogen, and make up an unexpectedly large proportion. The researchers conclude that the composition of the entire planet is not yet fully understood. Nonetheless, the current investigations confirm that the core is liquid – as suspected – even if Mars no longer has a magnetic field.

Reaching the goal with different waveforms

The researchers obtained the new results by analysing various seismic waves generated by marsquakes. “We could already see different waves in the InSight data, so we knew how far away from the lander these quake epicentres were on Mars,” Giardini says. To be able to say something about a planet’s inner structure calls for quake waves that are reflected at or below the surface or at the core. Now, for the first time, researchers have succeeded in observing and analysing such waves on Mars.

“The InSight mission was a unique opportunity to capture this data,” Giardini says. The data stream will end in a year when the lander’s solar cells are no longer able to produce enough power. “But we’re far from finished analysing all the data – Mars still presents us with many mysteries, most notably whether it formed at the same time and from the same material as our Earth.” It is especially important to understand how the internal dynamics of Mars led it to lose its active magnetic field and all surface water. “This will give us an idea of whether and how these processes might be occurring on our planet,” Giardini explains. “That’s our reason why we are on Mars, to study its anatomy.”


Khan A et al.: Upper mantle structure of Mars from InSight seismic data. Science, 373, (6553) p. 434-438.

Stähler S et al.: Seismic detection of the Martian core. Science, 373, (6553) p. 443-448. doi:10.1126/science.abi7730

Knapmeyer-Endrun B et al.: Thickness and structure of the Martian crust from InSight seismic data. Science, 373, (6553) p. 438-443. doi:10.1126/science.abf8966

Further information

InSight mission information

Detailed ETH News article: Advancing to the core thanks to marsquakes


New ETH podcast episode: One universe - two perspectives

New ETH podcast episode: One universe - two perspectives

While Domenico Giardini, Professor of Seismology and Geodynamics, already has his hands on Mars, Adrian Glauser, Senior Researcher at the Institute for Astronomy, has to be patient. Among many others, Adrian worked on the James-Webb-Telescope that shall finally launch this fall, with a delay of many years. Both researchers talk about their work in the ETH Podcast and contemplate the universe's dimension to time on planet earth.

You can learn more about the podcast here and listen to the episode on Spotify, Apple Podcasts, Stitcher and Google Podcasts.


After the storms: InSight detects large marsquakes

After the storms: InSight detects large marsquakes

NASA’s InSight mission detected two large marsquakes as summer emerges, the winds calm, and the dust settles. Now, after one Martian year (687 Earth days) the Marsquake Service led by ETH Zurich and operated by the Seismology and Geodynamics group and the Swiss Seismological Service is faster than ever at characterizing seismic activity on the red planet.

After several months of windy weather and dust storms, the atmosphere of Mars is becoming quiet again and the seismometer on the InSight lander started recording significant marsquakes. In early March, two new marsquakes with magnitudes of 3.3 and 3.1 were observed. Within 12 hours of the data arriving on Earth, researchers at the Marsquake Service at ETH Zurich determined the location, magnitude and, in one case, even the focal mechanism. This rapid result demonstrates that the whole chain of data recording, transmission, and analysis set-up by the InSight mission is functioning efficiently and rapidly. These moderately sized events recorded at over 1,200 km distance and by a single station (that would not even be observed by a similar station on Earth), are sufficient to confirm the emerging geological interpretation of the internal structure and surface tectonics of the red planet acquired over the past year on Mars.

Since the beginning of the Mars InSight mission on 26 November 2018, over 500 marsquakes have been recorded. With magnitudes between 1 and 4, these are small events compared to terrestrial earthquakes. Only a few of these marsquakes could be reliably located, determining both the direction and distance from the seismometer. The recently detected, larger marsquakes are located in Cerberus Fossae, a long graben system about 1,200 km from Elysium Planitia, where InSight landed. They have an extensional mechanism consistent with the regional tectonic setting showing that the Martian crust is still undergoing active deformation.

In the InSight mission, data recorded on Mars are relayed back to Earth in regular transmissions, often multiple times a day, via the NASA Deep Space Network. They are promptly compiled and controlled for quality by the Jet-Propulsion Laboratory (JPL) in the U.S. and the National Centre for Space Studies (CNES) in France, and delivered to the Marsquake Service located at ETH Zurich in Switzerland. The Marsquake Service is responsible for the first analysis of the Mars data, with the goal of identifying marsquakes and releasing periodic marsquake catalogues – the starting point for further scientific investigations. This is a collaborative ground service operation that includes on-duty seismologists from ETH Zurich, Institut de physique du globe de Paris (IPGP), University of Bristol, and Imperial College London. At the start of the mission, the data recorded on Mars was full of surprises and difficult to decipher. After a full year of processing seismic data from Mars, the Marsquake Service is now able to fully characterise the signals within just a few hours after having been recorded on Mars. This performance is comparable to that achieved by modern seismic networks on the Earth.

Recognizing the successful performance of InSight, NASA has approved the extension of the mission for a second Martian year. Unfortunately, the red dust which characterises all the pictures of Mars is also accumulating on InSight’s solar panels, reducing the panel’s power production and raising concerns about the long-term operation of the mission.

To learn more about the NASA InSight mission visit www.insight.ethz.ch or www.mars.nasa.gov/insight/

Access the joint press release about the recent Marsquake.


Martian moons have a common ancestor

Martian moons have a common ancestor

The two Martian moons Phobos and Deimos are thought to have originated from one and the same celestial body that orbited Mars between 1 and 2.7 billion years ago.

Phobos and Deimos are the remains of a larger Martian moon that was disrupted between 1 and 2.7 billion years ago, say researchers from the Institute of Geophysics at ETH Zurich and the Physics Institute at the University of Zurich. They reached this conclusion using computer simulations and seismic recordings from the InSight Mars mission.

Mars’s two moons, Phobos and Deimos, have puzzled researchers since their discovery in 1877. They are very small: Phobos’s diameter of 22 kilometres is 160 times smaller than that of our Moon, and Deimos is even smaller, with a diameter of only 12 kilometres. “Our moon is essentially spherical, while the moons of Mars are very irregularly shaped – like potatoes,” says Amirhossein Bagheri, a doctoral student at the Institute of Geophysics at ETH Zurich, adding: “Phobos and Deimos look more like asteroids than natural moons.”

This led people to suspect that they might in fact be asteroids that were captured in Mars’s gravity field. “But that’s where the problems started,” Bagheri says. Captured objects would be expected to follow an eccentric orbit around the planet, and that orbit would be at a random inclination. In contradiction to this hypothesis, the orbits of the Martian moons are almost circular and move in the equatorial plane of Mars. So, what is the explanation for the current orbits of Phobos and Deimos? To solve this dynamic problem, the researchers relied on computer simulations.

Calculating the past

“The idea was to trace the orbits and their changes back into the past,” says Amir Khan, a Senior Scientist at the Physics Institute of the University of Zurich and the Institute of Geophysics at ETH Zurich. As it turned out, the orbits of Phobos and Deimos appeared to have crossed in the past. “This means that the moons were very likely in the same place and therefore have the same origin,” Khan says. The researchers concluded that a larger celestial body was orbiting Mars back then. This original moon was probably hit by another body and disintegrated as a result. “Phobos and Deimos are the remainders of this lost moon,” says Bagheri, who is lead author of the study now published in the journal Nature Astronomy.

While easy to follow, these conclusions required extensive preliminary work. First, the researchers had to refine the existing theory describing the interaction between the moons and Mars. “All the celestial bodies exert tidal forces on each other,” Khan explains. These forces lead to a form of energy conversion known as dissipation, the scale of which depends on the bodies’ size, their interior composition and not least the distances between them.

Insights into the interior of Mars and its moons

Mars is currently being explored by NASA’s InSight mission, with ETH Zurich’s involvement: the electronics for the mission’s seismometer, which is recording marsquakes and possibly meteorite impacts, were built at ETH. “These recordings let us look inside the Red Planet,” Khan says, “and this data is used to constrain the Mars model in our calculations and the dissipation occurring inside the red planet”

Images and measurements by other Mars probes have suggested that Phobos and Deimos are made of very porous material. At less than 2 grams per cubic centimetre, their density is much lower than the average density of Earth, which is 5.5 grams per cubic centimetre. “There are a lot of cavities inside Phobos, which might contain water ice,” Khan suspects, “and that’s where the tides are causing a lot of energy to dissipate.”

Using these findings and their refined theory on the tidal effects, the researchers ran hundreds of computer simulations to track the orbits of the moons backward in time until they reached the intersection – the moment Phobos and Deimos were born. Depending on the simulation, this point in time lies between 1 and 2.7 billion years in the past. “The exact time depends on the physical properties of Phobos and Deimos, that is, how porous they are” Bagheri says. A Japanese probe scheduled for launch in 2025 will explore Phobos and return samples to Earth. The researchers expect that these samples will provide the needed details about the interior of the Martian moons that will enable more precise calculations of their origin.

The end of Phobos

Another thing their calculations show is that the common ancestor of Phobos and Deimos was further away from Mars than Phobos is today. While the smaller Deimos has remained in the vicinity of where it came into being, tidal forces are causing the larger Phobos to approach Mars – and this process is ongoing, as the researchers explain. Their computer simulations also show the future development of the moons’ orbits. It seems Deimos will move away from Mars very slowly, just as our Moon is slowly receding from Earth. Phobos, however, will crash into Mars in less than 40 million years or be torn apart by the gravitational forces as it nears Mars.


Amirhossein Bagheri, Amir Khan, Michael Efroimsky, Mikhail Kruglyakov and Domenico Giardini: “Dynamical evidence for Phobos and Deimos as remnants of a disrupted common progenitor”, Nature Astronomy, published online Feb 22nd 2021; DOI 10.1038/s41550-021-01306-2 https://dx.doi.org/10.1038/s41550-021-01306-2

Images of Phobos: https://www.esa.int/ESA_Multimedia/Images/2004/11/Phobos_in_colour_close-up2


Image of Deimos:


Article by Barbara Vonarburg.

Media reports

TV & Radio

Anche Marte ha i suoi terremoti (RSI Rete Uno, Radiogiornale 18.30, 24.2.2020)

Mars: l'EPFZ en mission (RTS Un, Le journal 19h30, 5.5.2018)

Bei der neuesten Mars-Mission "InSight" der Nasa sind auch Messgeräte der ETH Zürich dabei (SRF 1, Tagesschau Spätausgabe, 5.5.2018)

Die NASA will das Innere des Mars erforschen (SRF 1, Tagesschau Hauptausgabe, 4.5.2018)

La Svizzera partecipa a una missione internazionale su Marte (RSI LA 1, Telegiornale sera, 4.5.2018)

Forscher der NASA wollen dem Mars seine innersten Geheimnisse entlocken (SRF 1, Tagesschau 18.00, 4.5.2018)



La planète Mars tremble e livre quelques secrets (tdg.ch, 25.2.2020)

InSight: Der Mars bebt häufig, aber sachte (24.2.2020)

Der Mars bebt und rumpelt (nzz.ch, 24.2.2020)

Der Pulsschlag des Roten Planeten (derbund.ch, 24.2.2020)

Der Pulsschlag des Roten Planeten (Tagesanzeiger, 24.2.2020)

3, 2, 1...liftoff! ETH Zurich is onboard NASA's InSight mission to Mars (cnnmoney.ch, 7.5.2018)

Schweizer Wissen unterstützt neue Weltraummission (cafe-europe.info, 7.5.2018)

Schweizer Fachwissen stützt neue Weltraummission (greaterzuricharea.com, 7.5.2018)

Sur Mars avec l’EPF de Zurich (laliberte.ch, 7.5.2018)

Ein Stück Zürich fliegt zum Mars (nzz.ch, 6.5.2018)

InSight into Red Planet NASA's mission to Mars launches with Swiss technology onboard (swissinfo.ch, 6.5.2018)

ETH fühlt den Puls des Mars (blick.ch, 5.5.2018)

Nasa-Raumsonde InSight Richtung Mars gestartet (20min.ch, 5.5.2018)

«InSight»-Lander zum Roten Planeten gestartet (srf.ch, 5.5.2018)

Mission «InSight» gestartet: Die Landefähre ist zum Mars aufgebrochen (nzz.ch, 5.5.2018)

Jetzt startet ETH-Sonde zum Mars (tagesanzeiger.ch, 5.5.2018)

Schweizer Computer fliegt zum Mars (toponline.ch, 4.5.2018)

Schweizer Fachwissen stützt neue Weltraummission (unternehmerzeitung.ch, 4.5.2018)

Un sismomètre de l'EPFZ va s'envoler sur Mars (lematin.ch, 4.5.2018)

Expedition ins Innere des Mars (nzz.ch, 4.5.2018)

Nasa-Marslander Insight soll am Samstag ins All starten (DerStandard.at, 2.5.2018)

Schweizer Qualität Seismograf entlockt dem Mars Geheimnisse (swissinfo.ch, 2.5.2018)

InSIGHT va ausculter Mars pour nous permettre de mieux la comprendre (letemps.ch, 1.5.2018)

Die ETH Zürich fliegt zum Mars (Der Bund, 30.4.2018)

ETH-Forscher wollen mit Nasa-Mission das Innere des Mars erkunden (blick.ch, 30.4.2018)

Europäer fotografieren den Mars (Wiener Zeitung Online, 30.4.2018)

Die ETH Zürich fliegt zum Mars (tagesanzeiger.ch, 30.4.2018)

ETH-Forscher wollen das Innere des Mars erkunden (Futurezone.ORF.at, 29.4.2018)


La mission InSight dévoile ce qui agite le sous-sol martien (Le Temps, 26.2.2020)

Unser roter Nachbar bebt und rumpelt (Neue Zürcher Zeitung, 26.2.2020)

Am Puls des Mars (Süddeutsche Zeitung, 26.2.2020)

Marte, il suolo treme come sulla Terra (Corriere della Sera, 25.2.2020)

Auf dem Mars bebt es jeden Tag (Solothurner Zeitung, 25.2.2020)

Der Pulsschlag des Roten Planeten (Berner Zeitung, Ausgabe Stadt + Region Bern, 25.2.2020)

InSight: Der Mars bebt häufig, aber sachte (Keystone SDA, Schweizerische Depeschenagentur, 24.2.2020)

Ein Stück Zürich fliegt zum Mars (Neue Zürcher Zeitung NZZ, 7.5.2018)

Hier startet die ETH-Sonde zum Mars (Basler Zeitung, 7.5.2018)

Nasa-Raumsonde InSight gestartet (20 Minuten Zürich, 5.5.2018)

Expedition ins Innere des Mars (Neue Zürcher Zeitung NZZ, 4.5.2018)

InSight, une plongée dans les mystérieux sous-sols de Mars (Le Temps, 3.5.2018)

Den Mars entzaubern (Berner Zeitung, Ausgabe Stadt + Region Bern, 1.5.2018)

ETH will das Marsinnere erkunden (Der Landbote, 30.4.2018)

Bestes Seismometer für den Mars (Tages-Anzeiger, 30.4.2018)

ETH-Forscher wollen mit Nasa-Mission das Innere des Mars erkunden (Schweizerische Depeschenagentur SDA, 29.4.2018)