Voyager 1 Travels 1 Light-Day from Earth – 25.9 Billion Kilometers in a Day, 49 Years of Travel
According to NASA's official orbital data, the Voyager 1 probe will cross a symbolic and interesting distance threshold later this year: 1 light-day. Everyone knows what a light-year is, but a light-day is the distance light travels in 24 hours, approximately 25.9 billion kilometers, equivalent to over 160 astronomical units, and of course, there are also light-hours, light-minutes, and light-seconds.
It takes light only one day to cover this span, but humanity has spent over 49 years, almost half a century since Voyager 1's launch on September 5, 1977.
Originally, Voyager 1 wasn't even planned to travel this far; it was intended to observe Jupiter, Saturn, and their satellites and rings.
It flew past Jupiter in March 1979 and Saturn in November 1980. It should have rested after that, but miracles kept happening.
On February 17, 1998, it surpassed Pioneer 10, becoming the farthest human-made object from Earth at the time.
On August 25, 2012, it passed through the heliopause, becoming the first human object to leave the solar wind and enter interstellar space.
However, disappointingly, Voyager 1 has not yet flown out of the solar system, as it needs to pass through the Oort Cloud according to the range of the Sun's gravity.
At its current speed, Voyager 1 will take approximately 300 years to reach the inner edge of the Oort Cloud and another 30,000 years to pass through it, at which point it will have completely left the solar system.
Unfortunately, as its energy gradually depletes, its instruments are constantly shutting down, and it may soon lose contact with humanity altogether.
With the continuous advancement of human space technology, Voyager 1 will not be the first to reach the Oort Cloud.
The famous "Pale Blue Dot": On February 14, 1990, Voyager 1 took a picture of Earth from 6 billion kilometers away.