I had a friend whose summer job, a long long time ago, was to travel around an unsuspecting rural area, lay a heavy steel plate on the ground, and whack the plate with a sledge hammer. Apparently he also had some kind of seismometer or accelerometer nearby. This was apparently a cheap and dirty way to get some idea of the soil and rock below the surface.

This was on Earth, not Mars.

The question InSight and active pinging of Mars asks about generating artificial seismic events on Mars for InSight's seismometers to listen to. @DrSheldon's answer mentions that this is not part of the plan; that InSight is expected to return meaningful data without this.

It doesn't mean that it wouldn't benefit from it though.

What kinds of schemes might a frugal and/or clever space agency use to generate seismic events that would be meaningful and useful for InSight measurements of Mars?

I can imagine two classes, one to help verify nothing is wrong, so something local perhaps, and the other far enough away to give geological or even planetary information.

  • 5
    $\begingroup$ Maybe inSight could use its own self-hammering mole to generate very small local seismic events $\endgroup$
    – Dragongeek
    Commented Nov 19, 2018 at 10:35
  • 2
    $\begingroup$ @Dragongeek - My idea was to lay down a stick of dynamite, light the fuse and run. But yeah, a hammer works, too. :) $\endgroup$ Commented Nov 19, 2018 at 17:15
  • 3
    $\begingroup$ @DonBranson was the running part of your ideas as well? Very clever! :O $\endgroup$
    – uhoh
    Commented Nov 19, 2018 at 17:24
  • 4
    $\begingroup$ @uhoh Not at first. It's all about learning from your mistakes. $\endgroup$ Commented Nov 19, 2018 at 17:31
  • 1
    $\begingroup$ Depending on fuel availability & thruster orientations as orbital probes (satellites) get near the end of their useful operating periods it might be possible to deorbit a probe or two to impact Mars in a controlled manner & at time of when it would be expected. $\endgroup$
    – Fred
    Commented Mar 31, 2022 at 0:19

4 Answers 4


The traditional method (as used in the Apollo project) was to crash used SIVB stages into the Moon.

  • $\begingroup$ Since there may not be too many of those left, nor (at least) an easy way to get one to Mars, I wonder what other item might serve as an SIVB proxy? $\endgroup$
    – uhoh
    Commented Nov 19, 2018 at 11:01
  • 3
    $\begingroup$ There are a bunch of landers on Mars due in 2020. digitaltrends.com/cool-tech/future-mars-missions/2 apart the landers, each will probably have at least a heatshield and backshell impacting independently $\endgroup$ Commented Nov 19, 2018 at 11:18
  • 3
    $\begingroup$ There are a lot of spacecraft orbiting Mars right now. It's likely at least one of them will fail during InSight's lifetime, and so the scenario in this answer is quite plausible. +1 $\endgroup$
    – DrSheldon
    Commented Nov 19, 2018 at 14:51
  • 6
    $\begingroup$ This has been tried on Mars with the Mars Climate Orbiter. :-) $\endgroup$ Commented Nov 19, 2018 at 15:13
  • 2
    $\begingroup$ @MartinSchröder But the timing was terrible. $\endgroup$ Commented Nov 27, 2018 at 1:35

Let's examine what's already on InSight:

InSight components

  • A seismometer (SEIS). It's so sensitive that it is expected to be able to sense windstorms, dust devils, and the tidal forces of Mars' moon. To isolate the sensors from motions of the main body of InSight, SEIS is in its own pod that will be placed a few feet away by a robotic arm, and attached by an umbilical.

    The sensors can be recorded during the "impact" of this placement process, and there is a small chance that something useful could be learned from the results.

  • A burrowing temperature probe (HP3). It will be placed by the robotic arm, and then dig with an impact hammer up to 5 meters depth. The head of the "mole" is attached with a cable that has temperature sensors along its length.

    The vibrations caused by dropping the mole, as well as its digging, could possibly help the seismometer map out the nearby subsurface geology.

  • An X-band radio (RISE). This transmitter and transponder will work with antennas in the Deep Space Network to locate the position (within 2 cm) and velocity of Mars. It doesn't seem to have any moving components to create a seismic "ping".

  • The aforementioned arm. This could be manipulated to "thump" the surface around the lander.

  • Other sensors include pressure, temperature, wind direction and speed, and magnetic field. There is a laser retroreflector on the deck, a color stereo camera on the arm, and a color panoramic camera below the deck. I don't see how any of these could be used to create a seismic "ping".

  • Finally, the usual spacecraft components: landing legs, solar panels, computer, antennas, etc.

Therefore, the spacecraft itself has a limited capability to produce some seismic "pings", which might reveal the nearby subsurface geology. The most revealing observations will be by passive seismology and the other instruments.

  • $\begingroup$ It's so sensitive that it is expected to be able to sense ... the tidal forces of Mars' moon. Considering Mars' moons are only 7.7 and 14 miles across, that's amazing! $\endgroup$
    – Andy
    Commented Nov 20, 2018 at 16:21

To address the problem with martian atmosphere - maybe an impactor with high explosives could be better. Something like Tallboy bomb.

I think energy of the impact will not be higher than from a meteorite impact. Probably even much less. But intended impact have some big advantage - we know where and when exactly it happened. It can be very useful for calibration of seismic velocities model of Mars.

The main problem is cost, of course. The impactor should be specially designed. Stuff like old satellites or rocket stages is not dense enough and not stiff enough to impact martian surface with enough energy after encounter with the atmosphere. The impactor mission would cost at least 100-200 mln $ including launch.

  • $\begingroup$ I think impactors (kinetic devices) and explosives can be completely separate and alternative solutions and could be discussed individually. $\endgroup$
    – uhoh
    Commented Nov 19, 2018 at 15:31
  • $\begingroup$ First they send their 'probes' which was voyeuristic and creepy, but we put it down to different cultural values. And besides they naively landed away from any large population centers,. Then without provocation they started bombing us! What the hell! It is on. Powers up those old laser mining bots, yup the tripod ones. Cultural differences my ass, let's give them a taste of their own medicine! $\endgroup$ Commented Sep 7, 2020 at 23:46

Active seismology was actually used by Apollo 16. Small explosives were detonated to produce artificial seismic waves.


The mortar portion of the Apollo 16 Active Seismic Experiment.

Two experiments, the Active Seismic Experiment on Apollo 14 and 16 and the Lunar Seismic Profiling Experiment on Apollo 17, were performed to determine the detailed structure of the upper kilometer of the lunar crust. Both experiments involved detonation of a series of small explosives. The seismic waves or ground motions caused by these explosions were measured by a network of geophones. On Apollo 14 and 16, up to 19 explosions were detonated by an astronaut using a device called a "thumper" along a 90-meter-long geophone line. On Apollo 16, three mortar shells were also used to lob explosive charges to distances of up to 900 meters from the ALSEP. On Apollo 17, eight explosive charges were positioned during the three EVAs at distances of up to 3.5 kilometers from the LM. These charges had masses of 57 grams to 2.7 kilograms. Both the Apollo 16 mortar shells and the Apollo 17 explosives were detonated by radio control after the astronauts left the lunar surface.

These experiments showed that the seismic velocity (P wave) is between 0.1 and 0.3 kilometers per second in the upper few hundred meters of the crust at all three landing sites. These velocities are much lower than observed for intact rock on Earth, but are consistent with a highly fractured or brecciated material produced by the prolonged meteoritic bombardment of the Moon. At the Apollo 17 landing site, the surface basalt layer was determined to have a thickness of 1.4 kilometers, slightly higher than the 1 kilometer thickness determined from the Traverse Gravimeter Experiment.

  • 1
    $\begingroup$ Thank you for your answer. I've added some of the original information to your post. In Stack Exchange, "link-only" answers are discouraged because links rot over time and so the link-only answers become useless to future readers. I had no idea that astronauts were lobbing mortar shells and "blowing things up" on the Moon!? $\endgroup$
    – uhoh
    Commented Nov 27, 2018 at 1:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.