ASU, UA scientists unlock secrets of Mercury geology

The new issue of Science carries a special section on the results of the MESSENGER mission to Mercury, which arrived in January and imaged half of the part of the planet that was not seen by the Mariner 10 spacecraft in the 1970s.

Geology professor Mark Robinson at ASU is lead author on one paper in the journal that discovered widespread volcanism across Mercury. Impact craters are common, but Robinson and co-authors conclude that much of the planet was resurfaced by volcanic activity that is either low in iron, or where the iron is locked up in non-silicate minerals.

UA planetary geologist Robert Strom is lead author on a companion paper examining crater densities that supports the conclusion that planetary resurfacing by volcanism took place after the early bombardment phase.

[right: volcanism in Caloris impact basin (C); white arrows mark locations of young smooth plains whose composition appears related to the Caloris plains. Small volcanic centers formed by explosive eruptions (black arrows). Dark blue areas are older rocks that may be rich in the mineral ilmenite. Credit, NASA/Johns Hopkins University Applied Physics Laboratory/Arizona State University/Carnegie Institution of Washington]