As we wait in anticipation for NASA's New Horizons probe to make its historic Pluto flyby on July 14, 2015, the mission is about to cross another milestone - it will zoom past Neptune's orbit at 7:04 p.m. PDT (10:04 p.m. EDT) today (Monday), and it has already snapped a pixelated view of the outer solar system's ice giant from 2.5 billion miles away (around 27 times the Earth-sun distance).
Today's milestone is also a grand coincidence for solar system exploration. Precisely 25 years ago, on Aug. 25, 1989, NASA's Voyager 2 probe reached Neptune as it made its way to the outermost reaches of the sun's sphere of influence - a magnetic bubble called the heliosphere. Voyager 2 was the first spacecraft to encounter the majestic blue planet.
PHOTOS: Voyager 2's Epic Outer Solar System Odyssey
"It's a cosmic coincidence that connects one of NASA's iconic past outer solar system explorers, with our next outer solar system explorer," said Jim Green, director of NASA's Planetary Science Division, NASA Headquarters in Washington, D.C. "Exactly 25 years ago at Neptune, Voyager 2 delivered our ‘first' look at an unexplored planet. Now it will be New Horizons' turn to reveal the unexplored Pluto and its moons in stunning detail next summer on its way into the vast outer reaches of the solar system."