- The Eoarchean (IPA: /ˌiːoʊ.ɑːrˈkiːən/ EE-oh-ar-KEE-ən; also spelled Eoarchaean) is the first era of the Archean Eon of the geologic record. It spans 431 million years, from the end of the Hadean Eon 4031 Mya to the start of the Paleoarchean Era 3600 Mya. The beginnings of life on Earth have been dated to this era and evidence of archaea and cyanobacteria date to 3500 Mya, comparatively shortly after the Eoarchean. At that time, the atmosphere was without oxygen and the pressure values ranged from 10 to 100 bar (around 10 to 100 times the atmospheric pressure today).
- NASA’s Webb Captures Dying Star’s Final ‘Performance’ in Fine Detail (webbtelescope.org)
NASA’s James Webb Space Telescope has cast the Southern Ring Nebula in an entirely new light. By observing the nebula in mid-infrared wavelengths, Webb has unveiled the second, dusty star at the center of the nebula in far more detail. The star closely orbits its companion as it periodically ejects layers of gas and dust. Together, the swirling duo have created a fantastic landscape of asymmetrical shells. Webb’s near-infrared light image hones in on “spotlights” from the stars, where light travels through holes in the nebula’s dusty ejections.