Source: Modified from “The Most Massive Core-Collapse Supernova Progenitors,” by R. Waldman, In Astrophysical Journal, Vol. 685; October 1, 2008 (graph); Animation by Ryan Reid ...

A graph in the lower, right corner the quantifies the change over time by showing the area in millions of square kilometers covered by each age category of perennial sea ice. This graph also includes ...