Arctic sea ice appeared to have reached its yearly lowest extent on Sept. 13, NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder have reported. Analysis of satellite data by NSIDC and NASA showed that at 1.79 million square miles (4.64 million square kilometers), this year’s Arctic sea ice minimum extent is the eighth lowest in the consistent long-term satellite record, which began in 1978.