Outer Space

When you look at the night sky on a clear dark night, you can see thousands of stars. There are far more than you could count. And, they are way out there. They are very, very far away. It’s about the hardest thing to imagine about space. Let’s talk about the nearest star to us, the Sun. If somehow outer space were not an icy cold vacuum with nothing to eat, drink, or breathe, and we could drive there in a car, to get to the Sun at freeway speed of 100 kilometers/hour (61 miles/hour), it would take171 years of driving without stopping to sleep or get gas out in the near nothingness of space. That’s just to the Sun. To get to even the closest star, Proxima Centauri, would take 40,000 years. On top of that, most things, billions and billions of stars, are much, much farther away than that! It is just astonishing.

How do we know that everything is so far away? We have watched the sky for centuries. By watching carefully the motions of the points of light across the sky, humans have been able to estimate how far away objects are. It took us years, and years, but you can watch this episode in less than 29 minutes.

Bill might seem a little far out in this episode. Maybe he’s getting spacey.

The Big Ideas

Did You Know That?

• There must atoms of “dark matter” that we can’t see between the stars and galaxies or the universe wouldn’t have enough gravity to hold its shape?
• Many of the atoms that make up living things have even numbers of protons like iron 26, oxygen 8, and carbon 6, because they came from exploding stars?
• Our next robot mission to Mars in 2003 is going to have rovers with sundials to help us navigate on Mars?

Books of Science!

• “The Mystery of Mars“ by Sally Ride and Tam O’Shaughnessy. Published by Crown Publishing, 1999.
• “The Big Book of Space Flight Activities“ by Jani Macari Pallis, Editor. Published by McGraw Hill, 2000.