NASA's Voyager Spacecraft Discovers a 'Wall of Fire' at the Edge of Solar System

NASA has always strived to solve the intriguing mysteries of space. The organization's Voyager mission, launched in 1977, was also a step in that direction, according to IFL Science. The mission's objective was to investigate the edge of the solar system as well as the interstellar medium that existed between different stars. The initial Voyager mission consisted of two probes, both of which reached the border of the solar system. Their investigation revealed that what existed at the edge was a "Wall of Fire." As per reports, the structure's temperature ranged between 30,000 to 50,000 kelvin (54,000-90,000 degrees Fahrenheit). 

The solar system's border is typically understood to be the heliosphere, according to the Jet Propulsion Laboratory. The heliosphere is a protective layer of particles and magnetic fields facilitated by the Sun. It is placed around 11 billion miles (18 billion kilometers) from Earth. In 2018, Voyager 2 became the second spacecraft to go beyond the heliosphere. Voyager 1 was the first to achieve this feat in 2012. The layer ends at what has been labeled the heliopause. Researchers have long believed that the heliopause expanded and contracted based on the Sun's changing activities. This assertion was proved true by the fact that the two probes found the heliopause at different distances from the Sun.

Signals sent back by Voyager 2 helped researchers gain several insights regarding this little-known territory called the heliopause, according to Room. One of the most noteworthy observations was that the interstellar medium near the heliopause was hotter than the team previously believed. This high temperature could be a consequence of plasma getting more compressed than previously believed or due to some reconnection. 

This massive temperature, ranging between 30,000 to 50,000 kelvin, has led to heliopause being labelled as "Wall of Fire," per IFL Science. Though there are no literal fires in the region. Despite the extreme temperatures, both Voyager probes managed to pass through the heliopause without much damage. Scientists speculate that this was because material density beyond the influence of solar density was extremely low. This condition possibly facilitated the easy passage. 

Researchers collected many more insights from Voyager 2 about the universe beyond the solar system, stated the Jet Propulsion Laboratory. The two energetic particle detectors determined that beyond the heliosphere, heliospheric particles dropped dramatically while the quantity of cosmic rays increased. These changes confirmed to scientists that Voyager 2 was indeed in a new region of space. This region is transitional, which means it has the attributes of the solar system and what is beyond that. 

Both Voyagers have indicated that plasma in the interstellar space is denser than the plasma in the heliosphere. The readings also showcased that the heliosphere was leaky, releasing several particles into interstellar space. Voyager 2 also confirmed the earlier assertion gathered by Voyager 1 that the magnetic field just beyond the heliopause is parallel to the magnetic field inside the heliosphere. Ed Stone, project scientist for Voyager and a professor of physics at Caltech, is hopeful that the readings from Voyager 2 would aid experts in understanding whether the observations collected through Voyager 1 were specific to the route it had undertaken or were they definitive for the entire heliosphere.