Traveling at a distance of over 11.2 billion miles from the Earth, Voyager 2 spacecraft has found something weird in outer space. It has found that the density of outer space is increasing. This has challenged the notion that space is a vacuum.

Voyager 2 was launched in July 1977 as a part of NASA's Voyager Program. During its solar system voyage, Voyager 2 explored Jupiter, Saturn, Uranus, and Neptune. In 2018, Voyager 2 escaped the boundary of Sun's influence and became the second spacecraft to enter interstellar space after its twin counterpart Voyager 1. Since then, Voyager 2 has been beaming back information about the space beyond the Solar System.

The recent discovery about the increasing space density has surprised everyone. This is not the first time that such an increase in density has been detected. In 2013, Voyager 1 made a similar observation, but at a different location. The new findings have not only confirmed Voyager 1's observations but have also hinted that an increased surface density might be a widespread feature of Very Local Interstellar medium (VLIM).

The VLIM is the space outside the heliopause, where the heliopause is the Solar System's edge that the Voyagers have crossed.

Several theories have been put forth time and again to explain this density increase. One theoretical model suggests that the increase might be due to interstellar magnetic fields becoming stronger as they bend over heliopause. Another model predicts that the interstellar wind slows down as they approach heliopause and this builds up the density.

However, more data is needed to untangle the mystery of increased density.