Deep cold impact
Gravity measurements by the twin GRACE satellites have revealed a 480-kilometre-wide structure more than 1.6 kilometres below the surface of the east Antarctic ice sheet. It could be a crater more than twice the diameter of Mexico’s Chicxulub crater, which was caused by the impact widely believed to have killed off the dinosaurs.
Mea culpa
In a report released on 1 June, the US Army Corps of Engineers has acknowledged responsibility for flaws in the New Orleans hurricane protection system, which it describes as “a system in name only”. The levees, pumps and flood walls, which were…
