To travel to another star in our galaxy, finding another system of planets, and maybe even finding life there. Such has been the dream for scientists, futurists, and dreamers for centuries. But it has only been within the past century or so that human beings have been able to contemplate this as a serious possibility.
And while we are still a long way from being able to venture to other star systems, we are getting closer. In recent years, not one but two robotic spacecraft have managed to venture beyond our Solar System and make it into interstellar space.
These are the Voyager 1 and 2 probes, which explored the outer Solar System during the 1970s and 1980s and entered the interstellar medium in 2012 and 2018, respectively. In the not-too-distant future, they will be joined by two more spacecraft (Pioneer 10 and 11).
However, it will be many thousands of years before these spacecraft reach any of the closest stars to our Solar System. The same goes for any spacecraft that have launched from Earth in more recent years. For example, consider the New Horizons mission, which launched from Earth in 2006 and achieved its historic flyby with Pluto in 2015.
Since then, it became the first spacecraft to rendezvous with a Kuiper Belt Object (KBO) - known as Ultima Thule (2014 MU69) - and the fifth to achieve the necessary escape velocity to leave the Solar System. At its current velocity and heading, it is estimated that the spacecraft will reach interstellar space by 2040.
But like its interstellar peers, it will not reach another star system for thousands of years. In fact, even if we launched a spacecraft tomorrow using our most cutting-edge propulsion technology, it would still be many centuries or millennia before it ever made it to the closest star system.
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