DHAKA: At the edge of the heliosphere, you would just see unfathomably empty space, no matter which side of the invisible line you were on.

But scientists now have strong evidence that NASA’s Voyager 1 probe has crossed this important border, making history as the first human-made object to leave the heliosphere, the magnetic boundary separating the solar system’s sun, planets and solar wind from the rest of the galaxy.

“In leaving the heliosphere and setting sail on the cosmic seas between the stars, Voyager has joined other historic journeys of exploration: The first circumnavigation of the Earth, the first steps on the Moon,” said Ed Stone, chief scientist on the Voyager mission.

A new study in the journal Science suggests that the probe entered the interstellar medium around August 25, 2012. You may have heard other reports that Voyager-1 has made the historic crossing before, but Thursday was the first time NASA announced it.

The twin spacecraft Voyager 1 and 2 were launched in 1977, 16 days apart. As of Thursday, according to NASA’s real-time odometer, Voyager 1 is 18.8 billion kilometers (11.7 billion miles) from Earth. Its sibling, Voyager 2, is 15.3 billion (9.5 billion) kilometers from our planet.

Voyager 1 is being hailed as the first probe to leave the solar system. But under a stricter definition of “solar system,” which includes the distant comets that orbit the sun, we’d have to wait another 30,000 years for it to get that far, Stone said.

Another milestone for long after we’re gone: The probe will fly near a star in about 40,000 years, Stone said.

Source: cnn
BDST: 2112 HRS, SEP 13, 2013
SR/RIS