Still Going . . .

Voyager 1, humanity’s most well-traveled explorer, left the sun 100 astronomical units behind on August 15, meaning it is 100 times farther away than the earth is—9.3 billion miles. The spacecraft has been on the road for 29 years and, moving at a speed of about one million miles per day, could cross the boundary into interstellar space within a decade. It is now in the heliosheath—the outer skin of a bubble of gas called the heliosphere, which is formed by the solar wind—and returns data from these uncharted domains almost daily. —DS