Why track Galactic Tick Days?
Aside from just the fact that it’s fun, it also gives us a sense of just how massive our galaxy really is, and how much more there is to explore and learn.
Why did we choose the start date? Is the Tick Day really THAT old?
The first Tick Day was officially observed in September 2016. The start date (Oct 2 1608) was chosen to start because it’s the day that Hans Lippershey patented the telescope.
What is an arcsecond, why is it called that?
An arcsecond is 1/3600th of a degree, or 1/60th of an arcminute. We call it an arcsecond to distinguish it from the time keeping unit of a “second,” otherwise it would get confusing.
Wait, the Sun revolves around the Galaxy? How does that work?
More accurately, the entire solar system orbits around the Galaxy, us included. We orbit Sol just as it orbits the Milky Way, and Luna (the moon) orbits us, it’s layers upon layers of orbiting. The reason we have a relatively consistent orbit of 365.24 days is because we orbit Sol quickly, so we’ve had almost 2 billion orbits to clear away any smaller bodies from our path. The solar system has only had about 20 orbits since Sol formed so it doesn’t have a perfectly clear path.
Sol?
Oh! Sol is just the name of our Sun, hence why its called the SOL-ar system. Pretty cool, huh?
So how long is the Sun’s orbit of the Galaxy?
When Sol completes an orbit, we call it a “Galactic Year”. The length of a galactic year varies a lot, current estimates say that it should take 225 million years to complete another one, which is how we define a Galactic Tick Day. But it could take upwards of 250 million years. No matter what, it will take a very long time, which is why we divide it into Tick Days.