How far away 31 light-years actually is.
Past weeks of current writing, August 5th 2019, there’s been some news about a “Discovery of a new planet that may host life at only 31 light-years away”. Alright now, how far away 31 light-years really is?
This sounds like some good news because is the closest exoplanet we found that may host life, and it is at only 31 light-years (ly) away, meaning that we can almost see it.
Now astronomers can aim their equipment and get more information “easily”.
But can you see it? Well you can locate it in the sky. This planet is in the constellation of Hydra and you may be able to see it at night.
At 31 ly. this constellation appears in the following graphic of Stars within 50 ly. These constellations are visible with the naked eye from earth.
It fits in a graphic, you can see it with a lot of tools, and even with the naked eye. But GL 357 (HIP47103) is really far away.
Distance is tricky in space. So to put this in a perspective of time that we can all understand, and not to say something like, it will take 31 years travelling at the speed of light, which is not accurate, and humans can’t do yet. Is necessary to measure this in a different fashion.
Behold the “Voyager Time”. The Voyager 1 is no doubt the human built unit that traveled the most in space. For a while now it reached a constant and comfortable cruise speed of 17 Km/s. And if humanity was to endure a big journey out in space, with the tech it has now, is logic to say that 17 Km/s is humans cruise speed in space. So, at that cruise speed, how much to reach HIP47103?
Data:
31 ly = 1,960,473.4 AU* (Yeah, a million and something…. almost 2….).
*1 AU is 1 time the average distance between earth and the sun.
Distance traveled by Voyager 1 so far = 146 AU (Yeah, just a hundred, since the 70's….)
17 (km / s) = 3.58606536 Astronomical Units a year.
1,960,473 AU / 3.586 AU/year = 544.575 years.
So Five hundred forty four thousand, five hundred and seventy five years for a human made object such as Voyager 1 to reach HIP47103. And it is the closest planet that may be capable of hosting life found so far.
Do all of this mean that we are 500 thousand years away of ever finding another life form by ourselves?
This is one of the reasons why looking at the Universe makes you feel small.
