The space between our solar system and other stars is huge: several light-years, at least. For instance, we would have to travel between 3 and 4 light-years so that we will arrive at our nearest solar system called Alpha Centauri. It sounds like nothing for the outrageously vast space of the Universe, but we humans would need hundreds of years to travel such a distance with our current technology. For plenty of time, a lot of scientists believed that the space between stars is pretty much empty. But two human-made objects built in 1970 that left our solar system are ready to contradict the idea. Beware of the magnetic fields Not even when you suck all the material and even air out of a jar, there's no such thing as a completely empty space. That jar will still be filled with quantum fluctuations (aka virtual particles) that create themselves out of nothing and annihilate each other. As for interstellar space, it's also far from being truly empty. Michelle Bannister, who is an astronomer at the University of Canterbury in Christchurch, New Zealand, declared: \u201cWhen you look at different parts of the electromagnetic spectrum, that area of space is very different from the blackness we perceive with our eyes,\u201d She also said: \u201cMagnetic fields are fighting and pushing and tied up with each other. The image you should have is like the plunge pool under Niagara Falls.\u201d Over the decades, scientists have been gathering data about what the interstellar realm is made of. They had been observing the skies with radio and X-ray telescopes. Therefore, the outcome is that the interstellar space is composed of very diffuse ionized hydrogen atoms, dust, and also cosmic rays interspersed with dense molecular clouds of gas. Scientists were suspecting for a long time that there's no such thing as true 'nothingness'. In fact, nothingness itself shouldn't be defined by the absence of absolute everything, even space and time, when we're talking about pure science.