Astronomers have cataloged about 95 percent of the space objects wider than half a mile – those that could destroy civilization. But they have found less than 1 percent of the objects 100 feet across or larger, a class that includes the asteroid that flitted past Earth on Friday.
Increasing summer ice melt in the Arctic Ocean could shift global weather patterns and make polar waters more navigable. But scientists say forecasting Arctic ice and weather remains a massive challenge.
This week's good reads includes a profile of a Russian family that lived in isolation for 40 years, a young professor's return to Pakistan from the United States after 13 years, and efforts to end big game hunting in Africa.