Voyager 1 becomes the first man-made object to enter interstellar space.

The trip took 36 years.

The lonely probe, which is 11.7 billion miles from Earth and hurtling away at 38,000 miles per hour, has long been on the verge of bursting through the heliosphere, a vast, bullet-shaped bubble of particles blown out by the sun. Scientists have spent this year debating whether it had done so, interpreting the data Voyager sent back in different ways.

It hasn't sent back any pictures since 1990.