Hey, Space Fans!
You’re not alone—not on planet earth anyway; lots of people are into The Cosmos. After all, we have countless books on the subject, countless movies on the subject, educational endeavors at Space Camp, and NASA. It just goes to show that the interest in the final frontier is shared so much that we now have a day dedicated to it. May 1st was National Space Day. I’ve always had a passion for this incredible, mysterious expansion of space that we call The Universe. How can you not when it’s full of such beauty and wonder?
Since the dawn of man, we’ve pondered what mysteries the skies hold above us. And we finally answered some of our burning questions at the end of the Space Race when the Russians put the first person outside of the earth’s atmosphere (space!). The U.S. answered right back when we sent men to the moon.
Feats such as these have led to great discoveries and further investigations to understand what kind of environments make up our universe. We’ve come to discover a great deal of our universe through exploration and information sent back from probes. And yet, there is SO MUCH that we don’t know.
For instance all of the planets, asteroids, stars, nebulae, and other things that you can see only make up 4% of our universe. The rest is made up of stuff that cannot be seen, detected, or even understood. We call these unknowables dark energy and dark matter.
If it’s undetectable, then how do we know that it’s there? you might ask. It’s a fair question—if we can’t detect it how can we know it’s there?
Well, we live in the Milky Way galaxy. Galaxies are clusters of stars, stars which mostly all have their own collection of planets just like our Sun has its collection of eight planets (of which earth is the third one out). Just as the planets are held in their rotations around the stars, the stars are moving about a giant black hole at the centers of galaxies!—pretty cool stuff!
But what’s more interesting than that is to discover that astronomers have done the math—they’ve calculated the total gravitational pull, all the mass of the objects in certain galaxies within our galactic neighborhood. The numbers don’t add up to keep everything tied together the way that they are. In other words, something is missing from our equation of what keeps the galaxies together.
Do dark energy and dark matter play a role in binding the stars? Someday we may discover how this works. Keep learning about the astronomical world and, as always, thanks for reading!