Steven Leeper oversees Hiroshima's commemoration of the Aug. 6, 1945, dropping of the atomic bomb. The US presence at the memorial ceremony has grown, with even President Truman's grandson in attendance this year.
In a week, if the landing goes as planned, NASA's Mars Curiosity rover will be looking for signs of methane and other organic compounds in the atmosphere and the soil, which could turn up new clues in the search for life there.
Researchers studying the star system Kepler-30, which is 10,000 light-years from Earth, found that its three known worlds all orbit in the same plane, lined up with the rotation of the star — just like the planets in our own solar system.
The discovery of a new particle thought to be the elusive Higgs boson represents the culmination of nearly 50 years of research, and completes a theory about how the most basic constituents of matter interact with each other.
After six years of reform, Massachusetts has the highest rate of health-care coverage in the US, but effects of its 'tax penalty' on employers are less clear. Some fear penalties are hamstringing job creation.
Republicans and Democrats are putting their political spin on the US Supreme Court's historic and startling decision on the Affordable Care Act. As they head toward the presidential election, both Barack Obama and Mitt Romney have major challenges in interpreting the law.