Watch InSight's successful landing on Mars

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Coverage began at 2 p.m. Eastern (7 p.m. UTC). Landing started about 40 minutes later, the entire landing telemetry was streamed live through the briefcase sized Mars Cube One interplanetary "cube sats", and at around 3.01 p.m. EST they got first confirmation of the landing. First image from the surface arrived several minutes later, relayed through the cube sats, and the landing went without a hitch. See the timeline here NASA Landing on Mars milestones

Archived live broadcast of the landing
InSight lander artistic impression shows the mole deployed to right and the seismometer to left

More videos[edit | hide | hide all]

Inside Mission control with 360 degree vision during the EDL

Insight post landing press briefing recap
For more details: Watch Online

First images[edit | hide]

First clear image. NASAInsight tweet: "There’s a quiet beauty here. Looking forward to exploring my new home. #MarsLanding"

This was the first image:

First image from the Mars Insight lander. The dusty lens cover will be removed - it was there to protect the camera from dust thrown up by the landing itself

Some points of interest about this mission:

First robotic mole[edit | hide]

  • For astrobiologists, one particularly interesting thing about this lander is that it is the first one to use a robotic mole. It will drill to a depth of 16 feet (about 5 meters). This is of interest for astrobiology, especially for the search for past life. ExoMars will be able to drill to 2 meters using a different technique and nothing else has been able to drill to anything like this depth. Viking scraped a shallow trench and most just drill mms into rocks. InSight is not an astrobiology mission; it's drilling in order to get a heat profile and learn about heat flows to help study the Mars interior. But it is the first test of robotic mole technology on Mars.

The name is very apt. It's a little self contianed unit with a hammer that kind of hammers away and sinks into the ground as it hammers and the soil then closes up above it as it drills. it is just like a mole. If you could watch it you'd see it burrowing away into the soil and vanishing from sight just leaving a wire poking out of the ground.

This shows how it works:

For details see Taking the Temperature on Mars

The thing is, in the vacuum conditions conventional drilling doesn't work. You can't use lubricants because it is a near vacuum (and anyway you'd have all the weight of lubricants to source somehow). Meanwhile the regolith is quite soft. And you want to carry as little mass with you as possible, don't want long continuous drililng shafts. Moles seem to be the best way to drill there.

ExoMars uses a somewhat more conventional drill but if you want to go to any depth then usually the idea is to use a mole.

The UK Beagle 2 lander was the first and only previous mission to send a small robotic mole to Mars, it landed successfully but sadly wasn't able to open the last of its solar panels and signal back to Earth. It is pioneering technology that could be useful for future astrobiological missions to Mars, though sadly Mars 2020 won't have a drill able to drill to any significant depth. ExoMars will, to a depth of 2 meters, but using a different method.

In the press conferences they said that the self hammering mole can nudge its way past rocks of up to 2 cms width, can also get past rocks that present a slanting face but if it hits a flat rock face on it just has to stop. Where it landed they think it can probably reach to a depth of about 10 feet and possibly the full depth of 16 feet (5 meters). That would be a useful depth for searches for organics of past life not deteriorated by the cummulative effects of hundreds of millions to billions of years of surface cosmic radiation.

From time to time it releases pulses of heat. Then it looks at how long it takes for its own body to heat up. This gives it information about the conductivity of the surrounding soil (regolith).

Aim to be dull[edit | hide]

  • NASA's InSight mission picks perfectly dull landing site - unlike most landers, the aim is to be dull :). They aren't looking for interesting and varied geology or places where there could be past or present day life, indeed, the more typical and boring it is, the better for their mission objective to find out about Mars's interior.
"This artist’s concept shows InSight landed safely on the Elysium Planitia region of the Red Planet." NASA/JPL-Caltech

First continuous day/night weather station[edit | hide]

  • The lander also has a weather station which will be the first one to operate continuously, both day and night on Mars instead of just a few readings a day. It will record temperature, pressure, and wind direction and speed continuously. The reason it does this is because the seismometer will be affected by all these things. It is so sensitive that it will record even deflections of the surface due to passage over of a pressure variation in the atmosphere. As a side effect this means that we have the first continuous measurements from Mars which may well turn up surprising discoveries.

InSight will be monitoring pressure, temperature, wind strength and direction twice per second day and night, and also pressure as well (not sure how often for presure). For details: other instruments

Landing site[edit | hide]

Landing site - notice how close it is to the equator, NASA/JPL-Caltech
Landing site again. It lands about 600 km away from Curiosity in Gale crater, NASA/JPL-Caltech
Landing ellipse in Elysium Planitia, Mars Odyssey orbiter image, NASA/JPL-Caltech

First interplanetary cubesats[edit | hide]

  • How will NASA know when InSight touches down? - this also mentions an interesting first - first mission to Mars that will deploy cubesats into Mars orbit. They can relay back themselves and they can also maybe even take a photograph of the lander on the surface immediately after a successful landing (or of the crash site if it crashes, to help them figure out what happened). First interplanetary cube sats
Mars Cube One - the two briefcase sized 'cube sats' which succcessfully relayed back telemetry and also the first image from the surface. They were on a separate trajectory and did a flyby of Mars and then headed off into interplanetary space.
Mars Cube One shows the antenna array and the two solar panels to either side. It also has wide and narrow-field cameras, and a star tracker, and it can relay data back at one kilobyte /sec to Earth (so one megabyte would take 16 2/3 minutes to transmit). NASA-JPL

The Mars cubesats actually were sent to Mars on their own independent trajectories using tiny thrusters for course corrections. The big antenna is used to communicate back to Earth, a design that lets them focus the signal with a flat antenna. There is a small receiver to receive signals from Insight in the base of the satellite that deploys on springs. They communicate independently back to Earth too, the cubesats could fly to Mars by themselves so are true interplanetary cube sats. They are each about the size of a large briefcase and they are technology demonstrators. They successfully gave direct transmission back to Earth of the Entry, Descent and Landing, which arrived about three hours earlier than the signal relayed from its orbiters which record it and then retransmit. They also returned the first image from the Mars surface.

Ultrasensitive seismometers to map the Mars interior[edit | hide]

  • InSight Diary: The silence of space - exceedingly sensitive seismometers, so senstivie they couldn't find anywhere on Earth quiet enough to test them, when the tested them deep in a mine in the Black forest in Germany the strongest signal was from the sea, hundreds of miles away - which would be far stronger than any feeble Mars quakes. They could only really test them once they were in flight on the way to Mars.
  • The Viking Seismometers - how both Viking missions carried seismometers but they were only able to measure really major quakes. Viking 1 was not able to uncage its seismometer. The Viking 2 one did uncage but only spotted wind data apart from one signal that may have been a Mars quake. Showed that with 95% confidence, Mars is less active than Earth.
Possible Mars quake from Viking sol 8. If it was, the P and S waves are labeled and 2 and 3 are possible reflections from the bottom of the Mars crust. This is the only previous recording of a possible Mars quake as Viking 1 didn't deploy properly and the Viking 2 one wasn't sensitive enough to detect the quakes InSight hopes to find. NASA-JPL
File:The Martian interior.jpg
Artist's depiction of possible interiors for Mars which the Insight Lander mission will explore

Mars has an iron-rich core, silicate mantle, thin silicate crust and atmosphere. The thickness of the crust can be estimated using variations in gravitational field experienced by orbiters, and the topography maps from the Mars Global Surveyor laser altimeter. However the results depend on the density contrasts between core and mantle and are not unique, and there may also be further unresolved layering From geophysical models there may be two or more phase changes in the minerals that make up its interior. The satellite measurements seem to indicate a large and possibly liquid core but its size is not known.

The measurements from the Insight lander will help clarify this.

For more details of possible Mars interior structure see Internal Models of Mars (SEIS)

Animations of EDL and deployment of instruments[edit | hide]

Entry, descent and landing sequence

After landing, deploys the seismometer, and then the robotic mole experiments by lifting them onto the surface of Mars. The Viking seismometers were mounted on the spacecraft, this one is placed directly on the surface of Mars. This is hugely speeded up, the actual deployment takes about one month for each instrument and they should be ready to start measurement in spring 2019. Then it depends on how many Mars quakes there are but they expect the main science results in a preliminary way two years from now.

Meteorite impacts[edit | hide]

They expect also to detect impacts of Martian meteorites; one of their objectives will be to get a better idea of the impact rate. The seismometers will be able to detect even the one cm or so rise and fall of the surface due to passage over of Phobos the innermost tiny moon of Mars which will also help them make discoveries about the Mars interior. They can also detect the orientation of Mars - the RISE (Rotation and Interior Structure Experiment) experiment can detect the slight wobble of the north pole as the gravity of the sun tugs at it during Mars's elliptical orbit which will help decide if Mars has a liquid core and how large it is. the Reflexes of Mars

Analysis of regolith properties[edit | hide]

InSight's seismometer can also detect the reverberations from the self hammering mole. This could let it detect the position of the supposed regolith / solid rock boundary layer. If there are any significant layers of water beneath the surface it could detect these too, by variations in the elasticity of the rock.

Analysis of regolith properties using seismic signals generated by InSight’s HP3 penetrator (pdf)]

InSight's seismometer may even be able to detect liquid water or magma plumes from active volcanoes below the surface. See Measuring the Pulse of Mars (NASA)

Speculation could it detect Curiosity liquid brines[edit | hide]

Speculation: I've wondered if their seismometer will be able to detect the layer of brines that Curiosity found just a few cms below the surface. Curiosity found that it forms every day overnight and dries out in the daytime as it warms up, and found this layer indirectly through humidity measurements, whenever it drove over sand dunes. Not sure but the Elysia Planitium might be suitable ground for it to form.

The self hammering mole releases pulses of heat as it descends and it studies its own self heating curve to estimate the thermal conductivity of the regolith around it. You'd think if it traveled through a thin layer of brine a couple of cms below the surface it might notice a variation in thermal conductivity? See Heat probe: Taking the temperature of Mars. Perhaps the liquid brines might leave a distinctive heat signature? See also for technical details: The Heat Flow and Physical Properties Package (HP3) for the InSight Mission

If Elysia Planitium has salts below the surface that can take up water from the atmosphere it might have similar brines too, and if so, perhaps the mole could notice the brines as a more heat conductive layer just below the surface as it starts to drill? Especially if the conductivity varied and was highest in the early morning, it might be the Curiosity brines. Just an idea.

If this is a possibility there might be something to be said for drilling very slowly through the top 15 cms, sending frequent pulses of heat, and sending pulses from the same location through a day / night cycle, and monitoring to see if there is any day / night variation in the thermal conductivity that might indicate temporarily forming brine layers.

For more about these brines see

They will also use the seismometer's recording of the reverberations of the self hammering mole to gain insights into the structure of the regolith - it should be able to detect the interface between rock and regolith that they think should be present and determine the depth of the regolith. It could also detect any strong signals of water rich layers indirectly through changes in the elasticity of the rock. See Analysis of regolith properties using seismic signals generated by InSight’s HP3 penetrator (pdf)

Anyone know the answer to that?

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