The nature of the early martian climate is one of the major unanswered questions of
planetary science. Key challenges remain, but a new wave of orbital and in situ observations …

The climate of early Mars remains a topic of intense debate. Ancient terrains preserve
landscapes consistent with stream channels, lake basins and possibly even oceans, and …

INTRODUCTION Remote observational data suggest that large bodies of standing water
existed on the surface of Mars in its early history. This would have required a much wetter …

Reconciling the geology of Mars with models of atmospheric evolution remains a major
challenge. Martian geology is characterized by past evidence for episodic surface liquid …

The evidence for abundant liquid water on early Mars despite the faint young Sun is a long‐
standing problem in planetary research. Here we present new ab initio spectroscopic and …

We present results from geomorphic mapping and visible to near‐infrared spectral analyses
of the Jezero crater paleolake basin and its associated watershed. The goal of this study is …

We use a 3‐D general circulation model to compare the primitive Martian hydrological cycle
in “warm and wet” and “cold and icy” scenarios. In the warm and wet scenario, an …

Early Mars climate research has well-defined goals (MEPAG 2018). Achieving these goals
requires geologists and climate modelers to coordinate. Coordination is easier if results are …

Return of samples from the surface of Mars has been a goal of the international Mars
science community for many years. Affirmation by NASA and ESA of the importance of Mars …

Today, a 34 m global equivalent water layer (GEL) lies in the Martian polar‐layered deposits
and shallow ground ice. During the Amazonian, 3 m was outgassed, and 31 m was lost to …