"The boundary between the mantle and the core seems to be a touch under 1,000 miles below the surface, which is larger than some studies have suggested. The suggestion, according to an accompanying piece published in Science on Thursday, is that the iron-nickel core is less dense than previously predicted, but is in a liquid state as other studies have argued."
Here is a "selfie" of the InSight lander, taken on the surface of Mars.
A cutaway depiction of SEIS, a dome-shaped instrument that sits on the surface of Mars. The white outer layer shields the sensitive instrument from the environment.
