Interstellar Travel
Today I want to talk about Interstellar Travel. Interstellar Travel is basically traveling across the different solar systems.
As I mentioned earlier, even if we found life-sustaining conditions on another exoplanet in a habitable zone, we could not get there without traveling interstellar distances. I also mentioned that interstellar distances are measured in Astronomical Unit (AU - basically 1 AU = distance between the Earth and the Sun in our solar system, which is 93 million miles), or a 'light-year' - the amount of distance a ray of light travels in a whole year (roughly, this is six trillion - that is six followed by fifteen zeros - miles, or simpler, 6 times ten to the power of 15 miles. That is the same distance as 64 million AU or 32 million round trips to the Sun (of course no one can get close to the Sun because it's waaaaaaaaaaaay too hot!) - and (my dad tells me) a lot of frequent flyer miles! And as I mentioned earlier, the nearest stars - Proxima Centauri A and B (And their step brother star, Alpha Centauri) are 4.3 light years away (that is 26 trillion miles for the math whiz)..
So, what if someone wanted to visit these exoplanets? How fast can we go today? At what speed would we need to travel from the Earth to get to these exoplanets in a reasonable time? Scientists at NASA tell us that there is no reason why travel at close to the speed of light cannot be done (even at that speed, it would take us 4.3 years to get to the nearest exoplanet Proxima Centauri b, for example). They are also saying that right now, this can only be achieved at microscopic scale for atomic particles, and they are working on technologies that can create speeds at which interstellar travel would be possible. There is a really cool video here that explains this in detail. According to some estimates, travel to Mars can be done within a month and exoplanets within 25 light year radius would be accessible. That is really cool! So, if you are wondering how fast you can go today on our good old Earth, for example, a Jet aircraft can go at 600 miles per hour, taking you from San Francisco to New York in about 5 hours. They are now talking about bringing back 'supersonic' (that is faster (super) than the speed of sound (sonic) ) aircraft that could fly from New York to London in one hour (at 3400 miles/hour, or about Mach 4.5, a term used to describe how fast an aircraft goes as a fraction of the speed of sound).
One very famous person is really ambitious in being a pioneer in space travel, and that is Elon Musk, a billionaire entrepreneur who runs Tesla car company here. He has another company called Space X and he was talking about his space travel plans last month and has a really cool video here.
My dad tells me that all this space travel talk was the stuff of science fiction (remember Star Wars or Guardians of the Galaxy, anyone?) for a long time. It seems that according to Mr. Musk, we will be able to travel in outer space to establish Mars colony in the next 20-30 years. This means that people get to live on Mars! Now that is really exciting! That travel to exoplanets - that is many decades away, but now considered very possible.