Abstract

There is a large number of historical observations of transient celestial phenomena, always noticed as (problematic?) deviation from the otherwise seemingly eternal, unchanging heavens. In a new area called Terra‒Astronomy, we study transient astrophysical phenomena which potentially affect Terra (e.g. climate, biosphere, etc.) such as solar activity and nearby supernovae ‒ and we investigate them with terrestrial archives, both natural archives (e.g. 14C in trees and 10Be in polar ice as solar activity proxies, or 60Fe in the ocean crust indicating a nearby supernova) and historical archives (e.g. observations recorded in previous centuries to millennia). Written records from all civilizations offer high temporal and spatial resolution, e.g. for aurora observations to reconstruct solar activity. It is essential to correctly understand the historical reports, which are written texts in old to ancient languages, using a different terminology. True understanding means considering intentions of the authors, possible narratives and hidden quotations, etc.