What’s beyond our beautiful planet. What’s so different out there?

When my parents were children, going to outer space was a dream. When I was growing up, space exploration was a given and I barely noticed when there was news of another space mission.

My own children, and kids like you, are growing up in a world where not only is space flight normal, but some very wealthy people travel to space as tourists. Is it possible that your children will be part of a world where kids brag, “We went to space on Chol Hamoed”?

Only time will tell, but maybe we should find out a little more about what’s beyond our beautiful planet. What’s so different out there?

No Atmosphere, No Gravity, No Air Pressure

You’ve probably seen pictures of astronauts floating through space in their space suits, so you know there’s no air and no gravity.

Well, you’d be correct about the air. Once you travel about 62 miles (100 kilometers) above Earth, you’ve left Earth’s atmosphere and are in the vacuum of space. Vacuum means that there’s nothing there — no air, no molecules. (To be honest, there are some molecules out there, but so few, spread so far apart that it doesn’t really make a difference.) Being in a vacuum changes a lot of things, so this is very important.

The International Space Station (the ISS) is an enormous science lab floating in outer space, not too far past Earth’s atmosphere. The ISS was brought into space piece by piece and built in space between 1998 and 2011 by several different countries working together. Scientists from all over the world live and work together on the ISS. Astronauts from all over the world live there for months at a time. The ISS is filled with air almost exactly the same as the air on Earth, and is very tightly sealed, so none of it leaks out. Inside the ISS, astronauts don’t need special suits.

But actually, gravity is everywhere. Every object in the universe has gravity. The bigger the object, the stronger it’s pull on the things around it. Our sun is very, very big and has enough gravity to keep all the planets in orbit around it. Earth is much smaller than the sun, but still big enough that its gravity keeps our feet on the ground. The moon is much, much smaller than Earth and has less gravity — whatever you (or any person or object) weigh on Earth, you will weigh 1/6 of that on the moon. To experience zero gravity, someone would have to be very far from any star or planet.

The ISS is orbiting Earth not too far outside of Earth’s atmosphere where gravity is 90 percent of what it is on Earth. A person who weighs 100 pounds on Earth weighs 90 pounds on the ISS.