Earth lives in its own little bubble so to speak, cut off from the vast majority of the universe due to the Sun’s solar wind. This forms the heliosphere, a spherical bubble. This bubble was previously thought to have a long tail, but is now thought to be smaller and rounder.
The sun’s magnetic field is controlled by high-speed particles, or wind. This wind creates pressure, producing a bubble known as the heliosphere. The sphere holds the interstellar medium. Part of the reason the Voyager 1 was such a significant journey was that it passed beyond the heliosphere and into interstellar space. This breakthrough helped scientists measure the heliosphere’s boundaries in two directions.
Rethinking the Size and Shape of the Heliosphere
A recent article in Nature Astronomy spoke about the redefining of the heliosphere’s shape. Instead of having a comet-like tail, the heliosphere is a strong bubble with a powerful magnetic field. While this makes the heliosphere stronger, it also makes it much smaller than previously thought.
Most of the evidence comes directly from the Cassini spacecraft. The data the unmanned spaceship is collecting on its travels is nowhere near the edge of our heliosphere. While the spaceship is mostly designed to collect data, it is also being used to analyze partials trapped within Saturn’s magnetosphere.
The sun has an 11-year cycle, with a 2 to 3 year delay. The strength of the solar wind depends on where the sun is in the cycle and how the neutral atoms are bouncing back and forth, Astronomers previously believed that the delay formed a trailing heliosphere, rather than a circle.
Studies in the past have tried to challenge heliosphere theories. While a 2009 study suggested the spherical shape, these reports lacked any concrete evidence until the Cassini’s data had been pulled. This is a huge way to end its orbit around Saturn before returning to Earth.