The distance between solar systems aren't measured in centimetres, metres or kilometres. The distance is measured in Light Years, a light year is a distance although it has a name that implies it has more to do with time. A light year is 5,878,499,810,000 miles or 9,460,528,400,000 kilometers 1. A light-second is the distance a photon of light can travel in a second, roughly three and a half times round the Earth. A light-day is the distance light can travel in a day, a light-month etc... If we are ever going to reach another solar system, we are going to need to travel at many times the speed of light to ever reach our destination.
The term refers to travelling at or above the speed of light. Different television and film series call faster than light travel by different terms but they are all the same. In Star Trek - The Original Series, light speed is called Warp Factor, Star Wars, it is called Hyperspeed and in Farscape, it is known as Starburst. The fastest thing that we've put into space at the moment has been the Voyager Space Probes which have reached the end of the Heliosphere. The heliosphere is the area of the Suns influence and where intergalactic radiation meets our solar radiation. The voyager space craft is currently travelling at 62,136 km/h. 2. The New Horizons mission to Pluto is currently travelling at 58,536 Km/h. Voyager is not on a planned course to any particular star, it will take at present 40,000 years to come within 1.6 light years of AC+79 3888, a star in the Constellation of Camelopardalis.
As mentioned, the fastest man made object travelling in space is the Voyager space probe, we don't have anything that can carry humans at that speed. The Apollo spacecraft that took man to the moon took 3 days to get to the Moon taking off on the 16th July 1969 and reaching the moon three days later. If we are going to reach another star, we're going to have travel a heck of a lot faster. Any future space craft is going to need to carry all its own fuel to make the distance. The amount needed would be a massive amount and the space craft unless we came up with a better fuel type, would be uneconomical.
Rigil Kentaurus also known as Proxima Centauri in the Constellation of Centaurus is widely recognised as the second closest star to our own Sun. It takes light to travel from the star to us 4.4 years. It would take us in a space ship at light speed 4.4 years there and another 4.4 years back excluding however long we would spend exploring the Solar System. The star is a faint star and cannot be seen with unaided eye. It is not at present believed to not have any planets in orbit round itself. It is part of a three sun system.
What would happen if the space ship that we were travelling in hit an Asteroid in the path, would either the space ship or the asteroid be destroyed. Would the spaceship have to slow down to normal speed to navigate the masses of Comets that lie in the Oort Cloud that is estimated at being one light year from the Earth. We would need a space ship to have its own Gravity otherwise during the whole journey we would be weightless, travelling in the air from one place to another. Onboard the International Space Station, the astronauts float everywhere, they are expected to do two hours of vigorous exercise every day to ensure that their bones do not waste away because of lack of gravity.
According to Albert Einstein, nothing with mass can travel at the speed of light, only light particles can travel at that speed. Therefore a spaceship travelling at light speed is therefore not possible. However in June 2014, James Franson, a scientist in Maryland, United States believes that speed of light is actually slower than what it had long been held to be true. 3. If what James says is true and holds up, theories of speed might have to be ripped up and started again. The notion that nothing can travel at the speed of light was put forward in 1905 when he said light travels at a constant speed in a vacuum of space. Franson had noticed that optical light from a stars collapse had arrived 4.7 hours later than they should have been.
In 2011, scientists in Italy had discovered that some Neutrinos seemed to have violated the laws of speed. They announced neutrinos had arrived earlier than they should have. They announced this to the world and scientists from all over the world descended on them to investigate whether what they had discovered was true. Unfortunately, it turned out to be misaligned. 4.
Instead of using faster than light travel, another way to get from here to another part of the universe is to use a Wormhole. Wormholes are simplistic speak, a tunnel between one part of the galaxy or universe to another. They are featured in many science fiction such as Star Trek and Farscape. You're not travelling at the speed of light and so doesn't break the law on light speed.
Suppose a parent Sam had a child Ashley and left Ashley on Earth whilst Sam visited a planet in another part of the Galaxy. When Sam returned, Sam would find that Ashley had aged faster than the parent. This notion of what would happen was covered in the 2014 film Interstellar as Cooper leaves his daughter behind to visit potential new planets for living on in the galaxy.
People believe that Aliens have reached Earth and therefore faster than light travel is possible. The reason they give for not wanting to communicate with us humans is because we haven't yet reached the same level of intelligence as they are, the so-called Prime Directive as mentioned in the Star Trek franchise. The aliens also think we're too war like to be friends and have gone away. Any alien civilisation that has reached Earth and then turned back without saying a word would've made a pointless journey. Although we haven't sent anything to other planets physically, our radio transmissions from the early days of telecommunications have reached other planets and as far as we know, they could be making their own way here.