It seems like a pretty simple question to ask how much something weighs. Even if is super small like a feather or very large like a car. Whether you use pounds or some other system, all you have to do is put the object on a scale. However, what if that object is as big as a planet — or multiple worlds? Is this answer even possible to discover? While we have estimates of the weight of our galactic home, nailing down the exact weight is quite the task.
The most significant difficulty for precise measurement lies in the fact that most of our galaxy’s mass is in the form of dark matter, which gives off no light and is currently impossible to observe. So, scientists must do a great deal of estimating when it comes to the galaxy’s mass. Current estimates put the Milky Way’s estimated weight anywhere between 700 billion and 2 trillion times the mass of our sun, a standard unit of mass in astronomy known as a solar mass.
19. Our Galaxy Has a Massive Halo of Gas and Old Stars
If you aren’t already staggered enough by the vastness of space and our galaxy, here’s another titanic measurement: our galaxy is surrounded by a halo of hot gas that extends for hundreds of thousands of light-years. What does this mean? The halo, which comprises gas and the remnants of old stars, is believed to be at least as large as the entire Milky Way Galaxy itself. Also, just like the galaxy, the halo is rotating rapidly. The CHANDRA telescope first found evidence of this halo, which is indicated to extend at least 300,000 light-years beyond our galaxy but may go even further.
And if there is a halo that enormous, what other possibilities are out there? We could say the sky is the limit, but we have already surpassed the atmosphere’s threshold. You will probably hear Beyonce’s song “Halo” in a completely different light now. Are you feeling pretty small in a big world full of billions of stars and opportunities? Just wait until you discover how many stars are floating in the sky — keep reading to see the magical number!
20. We Don’t Know Exactly How Many Stars Are There
Have you ever wondered how many stars are in the sky? On a clear night, you can spot hundreds of thousands of teeny tiny lights twinkling in the distance. However, counting stars is not as easy as it might sound, especially when we know there are at least 200 billion in our galaxy. Pinpointing an exact number is almost impossible by any sort of visual detection method, as many stars are too dim for our current equipment or shrouded behind dust. Even if you could count them all, would you really want to? It would take an astronomical amount of time to count each and every single one — and to keep track of the ones you already counted!
The more common method used is to observe the speed of stars’ orbits within the galaxy, which gives an idea of the gravitational tug and therefore allows a rough estimation of the mass of the galaxy. This mass is then divided by the average mass of a star. However, given the number of times we had to say “rough,” “estimate,” and “average,” it should come as no surprise that there is a fair bit of room for error in this calculation. When it comes to counting stars, would you accept a difference of a billion or so? We may never know the real answer to how many stars are in the sky.