Are We There Yet? Ever wanted to go to another star? Well, that’s easier said than done. The closest star to the earth is Alpha Centauri. It is a mere 4.3 light years from earth. That means, that we could get there in about four and a half years if we could travel at the speed of light. But we can’t go that fast. In fact, traveling as fast as we can in space means that it would take a ship 40,000 years to get there. Humans will have to learn how to travel at light speed if we are going to explore other stars.
It’s Just That Big! Our solar system is on the edge of the Milky Way. It got its name because of the hundreds of thousands of stars in the area create a bright white, or “milky” glow in a telescope. But just how big is the entire milky way? Well, if you shrunk our entire solar system down to the size of a quarter, then the Milky Way would be bigger than the entire North American continent. That is Canada, the United States and Mexico combined.
Natural Spacemen? Human beings need all kinds of apparatus to survive in space. We need space suits. They keep us warm in the frigid temperatures of space. They keep the human body under pressure where there is no pressure at all. But what if there was a creature that didn’t need those things? There is. Tardigrades, or Water Bears are tiny eight-legged creatures that can survive almost anything. Nasa brought Water Bears into space and exposed them to the extreme cold, radiation and the vacuum of outer space and these tiny creatures survived them all. BBC Nature
The Space Chase. On March 18, 1965, Russian Cosmonaut Alexei Leonov became the first man to leave a spacecraft and float in outer space. A few months later, on June 3, American Ed White did the same thing. But forty years later, The United States worked with Russia and the rest of the European Space Agency to land the first probe on Titan, the second largest moon in our solar system. Titan is so big, it is almost the same size as the planet Earth. The Huygens Probe landed on Saturn’s moon. It just shows how far people can go when they work together.
Saturn’s Rings.. Saturn isn’t the only planet with rings, but it has the largest rings in our solar system. Ever wonder what they are made of? The rings are made of ice and rock that orbit around the planet. Some of the rocks are smaller than grains of sand, while others are bigger than the largest skyscrapers. The rings are so wide that they are about the same width as the distance between the earth and the moon. But they are very thin. They are only about half a mile thick. That means when the planet is tilted just right, the rings will seem to disappear. When Galileo first discovered Saturn’s rings, he was shocked when he couldn’t see them anymore. But when the rings came back into view, he realized that the disappearance was just an optical illusion.
Having a Ball. Most of the stars and planets we can see are spherical, shaped like a ball. This is because the planets are constantly spinning. So, gravity holds everything together in a ball. But not all planets are completely round. Saturn spins faster than most other planets and because of its composition, it’ slightly flatter on the top and bottom. This makes Saturn more of an oval. In addition, Saturn has moon that isn’t a ball at all. Instead, Saturn’s moon, Hyperion is shaped more like a hockey puck and is flat on two sides. This means that the moon doesn’t spin very well.
Gas Giants! Earth is made of rock and water. That’s why we can stand on it. But not all the planets in our solar system can say the same. Jupiter and Saturn are giant balls of gas surrounding a smaller rocky core. Saturn’s core is about the same size as our planet, but Jupiter’s core is much larger. Both planets have thick atmospheres made of Hydrogen and Helium. These gases are very light. In fact, Saturn is so light that the entire planet would float in a bathtub full of water. That is, if you happened to have a bathtub that was 80,000 miles wide!
Planetary Downgrade. In 1930, Clyde Tombaugh spotted a tiny planet near the edge of our solar system. He had been hired to find the elusive “ninth planet” spotted from time to time by other astronomers. Initially, it was called “Planet X.” However, when news of the discovery hit the world, an 11-year-old girl suggested the name Pluto after the Mythical god of the Underworld, and the name stuck. For more than 75 years, Pluto was included as one of the nine planets in our solar system. It was the smallest planet and, as time passed, other tiny planets were discovered. In 2006, the International Astronomical Union created criteria to show the difference between planets and “dwarf” planets. Pluto met two of the three rules, but it was not alone in its orbit. So, The IAU decided that Pluto wasn’t really a planet. Sorry Pluto.
Looking Back in Time? It takes time for light to travel. Even light from our own sun takes a little more than 8 minutes to reach Earth. Other stars are much further away. The next closest star is Alpha Centauri and it’s 4.3 light years away. That means it takes 4.3 years from the light of Alpha Centauri to reach earth. So, the light we see is already 4.3 years old. Other stars are much further away. With some of the new telescopes, we can see light that is over 13 billion years old. That’s almost 9 billion years before the earth began.Shooting Stars. When you see a star shoot across the sky, you aren’t really seeing a star. What you are witnessing is a piece of rock from out space at it hits our planet. These are called meteorites. There are several times every year when meteorites are common in different parts of the world. The Leonid Meteor Shower is visible by the whole world in mid-November. This is when Earth passes through a cloud of dust that a comet leaves when it passes between the Earth and sun every 33 years.