NASA's Voyager 1 has traveled farther than anything else that humans have launched into space. On Wednesday, it's set to reach a new milestone: reaching a distance that is one-light day away from Earth.
NASA is celebrating the occasion with the "Shine Bright for Voyager's Light-Day." Calling it a symbolic celebration, NASA is asking the public on Tuesday night to send Voyager's call sign V-G-R into the sky in morse code. Use a flashlight, phone light or anything that can blink a sequence.
If you want to take part:
V - Three quick flashes, one long flash
G - Two long flashes, one quick flash
R - One quick flash, one long flash, one quick flash
What exactly is a light-day?
A light-day is the distance light travels in 24 hours, or more than 16 billion miles.
This NASA spacecraft has traveled for nearly 50 years, launching Sept. 5, 1977.
Over the course of its mission, Voyager 1 has conducted flybys of Jupiter and Saturn. In 1979, it discovered a faint ring system on Jupiter. In 1980, the spacecraft took detailed photos of Saturn's rings and moons.
While on its journey, on Feb. 17, 1998, Voyager 1 overtook the U.S. space probe, Pioneer 10, becoming the most distant human-made object in existence. It and its twin, Voyager 2, are the only spacecraft to have operated outside of the heliosphere, which acts like a protective shield of the solar system.
Voyager 1 reached the interstellar boundary in 2012. Its interstellar mission continues to chart and measure the magnetic fields, particles and plasma waves outside the sun's heliosphere and the atmosphere of other stars.
Earlier this year, NASA elected to shut off Voyager 1's Low-energy Charged Particles experiment, or LECP, which has helped scientists map the structure of space, in order to save power. Scientists said this could keep the probe alive longer..
Voyager 1 has two science instruments still running: one that measures magnetic fields and another that listens for plasma waves.
In addition, the Voyager spacecraft is carrying the Golden Record – an interstellar "time capsule" to communicate Earth's story to extraterrestrials.
The gold-plated record contains 115 images, natural sounds such as surf, wind and animals, and spoken greetings in 35 different languages. Included are instructions, in symbols, on how to play the record and the origin of the probe.
Voyager 1 is estimated to reach "light-day status" at 5:16 a.m. ET on Wednesday, after 49 years, two months and 11 days of travel.
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