NASA announced Monday that its Voyager 1 is currently floating through interstellar space.
The announcement comes almost two years after the probe was reported to have left the heliosphere in August 2012, according to NBC News. The heliosphere is referred to as a bubble containing charged particles and magnetic fields surrounding the sun.
NASA scientists studied measurements made by Voyager 1 during the beginning of a coronal mass ejection (CME), an explosion that resulted in a shock wave that caused noticeable vibrations in the particles surrounding the probe. Researchers calculated the density of Voyager 1's surroundings and found it to be much higher than the density observed in the outer layers of the heliosphere. They then concluded the probe had entered a new cosmic realm.
The shockwave of the CME, which erupted in March 2012, reached Voyager 1 in April 2013, NBC News reported. The research team then collected data from a smaller, 2012 CME they hadn't noticed before. Officials were then able to find the probe's entry into interstellar space in August of that year by combining data from the two events.
The space agency established confirmation of the entry after receiving data from a third CME shock observed by Voyager 1 in March of this year, CBS News reported.
"We're excited to analyze these new data," said Don Gurnett, the principle investigator of Voyager 1's plasma wave tool. "So far, we can say that it confirms we are in interstellar space."
Interstellar space begins at the end of the heliosphere, but the probe somehow still remains inside the solar system. A shell of comets called the Oort Cloud surrounds the solar system, and it has not been determined how far away it is located from Earth. NASA scientists estimated it will be another 14,000 to 28,000 years before Voyager 1 leaves the Oort Cloud.
Voyager 1 was launched into space two weeks after its twin probe Voyager 2 in September 1977, obtaining views of Saturn, Neptune, Jupiter, Uranus and their moons on its journey, CBS News reported. Voyager 2, which traveled in a different direction through the solar system, is still active and set to follow Voyager 1 into interstellar space in a few years.
