Saturday, July 30, 2011

A Look At Our Solar System

I love showing this youtube video about the asteroid discoveries in our inner solar system. Scott Manley takes the positions of detected asteroids, and highlights them as they are discovered. The final colors indicate how close they are to the Earth's orbit:

Red= Earth Crosser
Yellow= Earth Approachers (coming within 1.3 AU)
Green = All Others

The discoveries tend to follow the Earth's orbit because asteroids are best seen opposite the sun, when they are most illuminated. It's also interesting to see that discoveries go way up in the 1990's, when satellites start coming online. This is a cool way to highlight the importance of technological advances to scientific discoveries.

And, if you think this looks like a crowded mess, the Kuiper belt around the outer solar system is about 20 times as wide!

I love videos like this because they are sobering reminders of the vastness of space. As dense as these asteroids look, they won't collide with each other. In fact, movie scenes of spaceships dodging chunks of rocks in the Asteroid Belt is just plain wrong. The Asteroid Belt is mostly made of empty space. Yup. That's right. That's how BIG space is!

In the spirit of the late Carl Sagan, I sometimes think about how tiny the Earth is in this video. I really try to visualize it's place in our tiny corner of the Milky Way. It's just one planet circling one average sun with a half million other chunks of rock. Then, sometimes I think about the wars fought over this planet - the wars of death and human misery that were caused by zealous rulers intent on owning a piece of this tiny rock. You wouldn't be able to see the boundaries we fight so fervently for. Astronomy is, like so many people say, a humbling field. In the grand scheme of things, everything just seems so . . . small.


  1. If I had a broom big enough I'd want to clean it all up in a neat orderly manner. Haha just looking at the order of our solar system puts my nesting into full gear! You should look at my's becoming more and more orderly each day.

  2. Ha ha! I don't know if that would do you much good! The equilibrium state of the universe tends to perfect internal disorder.

  3. Gah until you look at it and then for some reason it changes it's behavior....I was watching "through the wormhole" the other night and it was talking about how protons will make a wave pattern on a wall when you aren't looking at them but the second you put a camera on them they behave's kind of like they are living conscious things...the universe is really confusing..

  4. Ah, yes, quantum mechanics truly is strange. What you're referring to is a consequence of how we measure things and how the universe works at small scales. In quantum, all particles are really wave packets in a superposition of many states. In simple terms, this means that at any time, there are many possible places a particle can be in. Indeed, it IS in all of them at the same time. That is, until we measure it, which forces the wave function to collapse to one position, at one time.

    Still confused? Don't worry, I find quantum hard to understand too (Einstein wouldn't believe it either!). However, it's what the math says, and it's repeatedly verified every time you use your cell phone.