How A Galaxy Forms

Our Sun is just one of somewhere between 200,000 million and 400,000 million similar stars but to get from one side of the galaxy to the other, well you’d need to pack a big lunch.
Technically, it’s possible to build a craft that could travel close to the speed of light. It would have to be very large to accommodate enough fuel to burn constantly for several years, but eventually it could reach speeds approaching 186,000 miles per second. At this speed you could get to the middle of our galaxy (once you decide where exactly that is) in about 20,000 or maybe 30,000 years. Given that the distance between galaxies is many times more than the width of a galaxy, there’s probably not much chance of visiting another galaxy anytime soon.

How Many Galaxies Are There?

The name ‘galaxy’ is from the Greek word for milk which is how they described the whiteish appearance of the band of light we know as our home galaxy. Each of the 170 billion galaxies is indeed a group of stars, but much more than that. They almost certainly hold billions of planets, star systems, star clusters and in most cases, a massive black hole near the centre.