4MOST Messenger issue
4MOST is a new wide-field spectroscopic survey facility under development for the four-metre-class Visible and Infrared Survey Telescope for Astronomy (VISTA) at Paranal in Chile. It will be the largest spectroscopic survey facility of its kind in the Southern hemisphere and address today's most pressing astronomical questions in the fields of Galactic archaeology, high-energy astrophysics, galaxy evolution and cosmology. The 4MOST design allows tens of millions of spectra to be obtained over the course of five years of operations, even for targets distributed over a significant fraction of the sky. 4MOST is currently under construction by an international consortium of 15 institutes, of which Hamburg Observatory is a leading member.
Now, a special issue of the European Southern Observatory's (ESO) The Messenger has been published, which is entirely dedicated to 4MOST. It contains 13 articles, written by the 4MOST Consortium, which introduce 4MOST to the ESO community. Three overview articles describe the 4MOST project and instrument, the 4MOST science operations and its current survey plan, while another ten articles describe the scientific plans of the 4MOST Consortium.

This special 4MOST issue of The Messenger was published in preparation of the joint ESO/4MOST workshop Preparing for 4MOST: A community workshop introducing ESO’s next-generation spectroscopic survey facility. This workshop, in turn, is meant to help the community prepare for a Call for Letters for Intent for Public Surveys with 4MOST, expected to be issued by ESO in mid-2019. The publication of the 4MOST Messenger issue thus marks the beginning of an exciting process, leading to the definition of the final 4MOST Survey Programme for the first 5 years of its operations.