The NASA Voyager probe that is currently travelling out of the Solar System has its own Twitter page! See it here: NASA Voyager. This probe has withstood amazing levels of radiation and kept up transmitting information back to NASA. On the sixth of September, the 35th anniversary of the launching of the Voyager probe was celebrated. Now it is 11,000,000,000 miles from the Sun; it is the furthest man-made object from the Earth. We might be able to catch up with the Voyager probe in the future if we had technology that allowed us to travel through space at an immense velocity and go past the heliosphere into interstellar space for the first time. Travelling into deep space would allow us to see such objects as the theoretical Quark stars formed from the degeneration of Neutrons into their component up and down quarks and therefore become an even denser sphere. An electroweak star is a star that is formed when the pressure outwards formed by radiation balances out the immense pressure that is trying to compress the star into a black hole. It is amazing that the core would only be the size of an Apple and would weigh twice that of the Earth. That is how dense exotic matter can become when it is compressed enough by the mass of the material above.
Such a massively dense object is possibly dwarfed by the preon stars; these would be even denser than a Neutron star, but they could not be too large as they would form a black hole and collapse under the immense mass they would form. But they are a good distance from us and there is no real threat to us if something like a gamma-ray burst or other explosion were to happen in the near future. The Voyager 1 probe will be passing close by the star Gliese 445 in about 40,000 years 1.6 light-years away. This is truly amazing. If the space shuttle was travelling at the speed that the Voyager 1 probe is currently; which is about 38,120 miles per hour; it would take 73,775 years to reach our nearest star Proxima Centauri. That is a good visualisation of how far away the stars in the sky really are. There are stars that have planets around them that could harbour life, but if they are 200 light-years away it would take millions of years to reach them at that speed. It is amazing that there have been theories put forward that the stars like our own could harbour life after they turn into a white dwarf star. We can not even imagine what life would look like if it could exist on the surface of a white dwarf star. I saw that theory years ago on the Discovery channel; I am not sure if this is possible; but who knows what is possible when life is so abundant on the Earth; it could exist in such an exotic environment as the surface of a white dwarf star.
The white dwarf stars could support life on orbiting stations or on captured planets due to the fact that they can last for a very long time indeed and they would enable a long-lived alien civilisation to live for a long time after the yellow dwarf and red giant stars have died out; this is one method of survival many billions of years into the future after all the other stars have died out. Eventually, the Voyager probe could encounter some kind of alien civilisation countless billions of years in the future, but it would be so far from Earth by then that it would be doubtful that the finders would be able to find their way to Earth using the guide on the golden record. Unless they are very advanced and knowledgeable enough about the Universe that they could actually trace its trajectory back to Earth; but it is more likely that we could simply catch up with it and bring it home again to rest in the Smithsonian. With near-future technology like nuclear propulsion; we could travel to another star in 113 years at massive velocity, but this would mean that time would travel slower on the spacecraft than it would back on Earth and this would have interesting ramifications for the crew. Travelling very fast would mean that millions of years would go by on Earth and only a few years would pass for the crew of the spacecraft. They might leave in the year 2099 and come back in the year 200,000,000. What effect would that have on them?
But this is one way to open up interstellar travel to mankind; the distances are so immense that anything at the speed of the Voyager probe would take longer than any lifespan to reach any star outside the solar system. Travelling to another galaxy would still be impossible; this would require some more exotic method of space travel like folding space or creating a wormhole to travel more quickly by using a shortcut through space. Travelling through space at 80% of the speed of light would mean that if the spacecraft was hit by a single dust particle it would be destroyed in a huge explosion due to the kinetic energy that is released by such a small object hitting the spacecraft with such velocity. And the radiation encountered by the spacecraft would be enormous. The electromagnetic ramscoop was another technology that could allow travel to the stars, but it is not really a possibility at the moment. Warp drive could be a technology that could take us to the stars; the Alcubierre drive is one drive technology that still provides some possibility for human exploration of the Universe. The spacecraft would have to be encased in a bubble of spacetime that was separate from the rest of the Universe; this would insulate the spacecraft from the effects of time dilation. This means that we would be able to travel through interstellar space without the time travel that results from travel near the speed of light. Sure; the distant galaxies would still be too far away for us but the nearby stars would be still within our reach.