Antarctica developed a continental-scale ice sheet 34 million years ago while Earth was about 5°C warmer than today — helped by slow-moving mantle waves that had spent more than 100 million years lifting its interior high enough for permanent ice to survive.
Before JWST began science operations, a dust-sized particle struck one segment of its 6.5-metre mirror at hypervelocity and left an uncorrectable deformation — damage revealed because Webb can detect nanometre-scale changes in its own optical surface.