NASA Mission Proposed to Investigate Exoplanet 'Radius Valley' Mystery
Planetary scientists are proposing a new mission, the Early eVolution Explorer (EVE), to investigate a long-standing mystery regarding exoplanet sizes. For over a decade, researchers have observed a distinct lack of exoplanets with a radius approximately 1.8 times that of Earth, a phenomenon known as the 'radius valley.' This proposed NASA mission aims to understand why planetary evolution leads to two primary categories: 'super-Earths' and 'sub-Neptunes.'
Planetary scientists are grappling with a persistent debate that has spanned more than a decade: the mystery of the 'radius valley' among exoplanets. This phenomenon refers to the noticeable scarcity of exoplanets whose radius measures approximately 1.8 times that of Earth, pointing to an unexplained aspect of planetary evolution.
The observed exoplanet population predominantly falls into two distinct classifications. Planets smaller than this threshold are generally known as 'super-Earths,' which are understood to possess rocky internal structures. Conversely, exoplanets exceeding this size limit are typically identified as 'sub-Neptunes,' often appearing more gaseous or 'puffy.' Despite extensive research, scientists lack a comprehensive understanding of the precise evolutionary mechanisms that compel planets to diverge into these two categories, creating such a pronounced size gap.
In an effort to shed light on this fundamental question of planetary science, a new mission proposal has been developed, dubbed the Early eVolution Explorer (EVE). The EVE mission is specifically designed to investigate the conditions and processes that dictate why the trajectory of planetary evolution results in this specific bifurcation. The detailed concept for this proposed mission is accessible to the scientific community in a preprint form via arXiv.
According to Phys.org, the Early eVolution Explorer mission aims to provide crucial data that could resolve this long-standing exoplanet enigma.
