Remember the Voyager 1 probe? It's 35 years old now, but it's still out there exploring the far reaches of our solar system, and this week NASA announced that it found something amazing and unexpected: a "magnetic highway" that serves as the "exit ramp" to the rest of space.
NASA made the announcement yesterday, when it was a bit overshadowed by news coming from Mars, but the Voyager discovery also bears discussing, because it's shed new light on how our solar system connects to the rest of the galaxy.
The "highway" was discovered when Voyager's instruments began reading a large increase in high-energy charged particles. That should have meant that Voyager had just exited the heliosphere (the large "magnetic bubble" that contains our solar system and our sun's magnetic field), but the probe's magnetic field instrument still showed an east-west orientation consistent with the sun's magnetic influence (it is believed that the magnetic field in interstellar space, outside the heliosphere, has a more north-south orientation).
According to Johns Hopkins Applied Physics Lab, a NASA partner, that means Voyager is now in a transitional region where particles from inside our solar system leave for interstellar space and interstellar particles enter the heliosphere.
In a written statement, the Johns Hopkins Lab said that this region is where the magnetic field lines of the heliosphere and interstellar space connect, which allows "lower-energy charged particles that originate from inside our heliosphere ... to zoom out, and higher-energy particles from outside to stream in."
It's an exciting discovery, especially when you consider how long it took Voyager to make the trip. The probe has been traveling further and further away from Earth since its launch in 1977, and it's roughly 122 astronomical units from Earth (one AU is roughly the distance from the Earth to the sun). It's now in the heliopause, where interstellar and solar wind pressures balance, and it's unclear how long it will stay there. It could be another two or three years before it travels beyond the heliopause, but when it does it could finally exit our solar system into previously unexplored territory.
(Via Huffington Post)