## Determine the thickness and structure of the crust

• Determine the crustal thickness with a precision of plus or minus 10 kilometers (6.2 miles). The pre-InSight estimates are that the crust is about 65 kilometers (40 miles) thick, plus or minus 35 kilometers (22 miles).
• Resolve crustal layers with a thickness of 5 kilometers (3 miles) or greater. Prior to InSight, there has been no certain knowledge about crustal layering.

## Determine the composition and structure of the mantle

• Determine the velocities of seismic waves in the upper 600 kilometers (373-mile) of the mantle to a precision of plus or minus 0.25 kilometer per second (560 mph). Mantle composition can be inferred from seismic velocities. The pre-InSight estimates are that velocity of seismic waves through the mantle is about 8 kilometers per second (about 18,000 mph) with an uncertainty of plus or minus 1 kilometer per second (about 2,200 mph).

## Determine the size, composition, and physical state of the core

• Positively distinguish between a liquid and solid outer core.
• Determine the radius of the core to a precision of plus or minus 200 kilometers (124 miles). Current estimates are that the core radius is about 1,700 kilometers (about 1,050 miles) plus or minus 300 kilometers (186 miles).
• Determine the core’s density to a precision of plus or minus 450 kilograms per cubic meter (28 pounds per cubic foot). Core composition can be inferred from density. The pre-InSight state of knowledge is that the core density is about 6,400 kilograms per cubic meter (400 pounds per cubic foot) plus or minus 1,000 kilograms per cubic meter (62 pounds per cubic foot).

## Determine the thermal state of the interior

• Determine the heat flux from the planet’s interior at the landing site to a precision of plus or minus 5 milliwatts per square meter (one-half milliwatt per square foot). Pre-InSight estimates are that the heat flux from the Martian interior is about 30 milliwatts per square meter (3 milliwatts per square foot) plus or minus 2.5 milliwatts per square meter (0.23 milliwatts per square foot).

## Measure the rate and geographic distribution of seismic activity

• Determine the rate of seismic activity to within a factor of two; determine the distance to the epicenter of a seismic event to within 25 percent; and determine the azimuth (compass direction) to the epicenter to within 20 degrees. None of these values have previously been measured.

## Measure the rate of meteorite impacts on the surface

• Determine the meteorite impact rate on Mars to within a factor of two. Current estimates are within a factor of about six.