There was, however, a recent paper published suggesting that there is still liquid magma beneath the Mars surface based on seismic activity:
"Magma on Mars likely", by Marianne Lucien, 27.10.2022
Since 2018, when the NASA InSight Mission deployed the SEIS seismometer on the surface of Mars, seismologists and geophysicists at ETH Zurich have been listening to the seismic pings of more than 1,300 marsquakes. Again and again, the researchers registered smaller and larger Mars quakes. A detailed analysis of the quakes’ location and spectral character brought a surprise. With epicentres originating in the vicinity of the Cerberus Fossae - a region consisting of a series of rifts or graben - these quakes tell a new story. A story that suggests vulcanism still plays an active role in shaping the Martian surface.
<https://ethz.ch/en/news-and-events/eth-news/news/2022/10/mag...>
(I found the article above after initially assuming Mars was completely geologically dead, which had been the consensus until recently. Had to re-write my response ;-)
And then the study of those objects, cf. geology, would be.... no, wait.
(Is there a generic prefix for just planetary bodies that we should be using? If so, what is it? If not, why not?)