Sean Solomon and members of the MESSENGER mission to Mercury team participated in a press conference at NASA Headquarters today at 1 p.m. EST to discuss initial findings—many surprising—from the spacecraft’s historic first flyby of Mercury on 14 January. Among other topics, the group discussed several images of the planet that provide more detailed information on surface materials than had previously been known; measurement of Mercury's magnetic field and sodium tail; the first laser altimeter profile for the planet; and the discovery of a remarkable geographic feature in Mercury’s Caloris basin, previously unseen by Mariner 10, and nicknamed “The Spider” by the science team.