The Fall of our Stars

A Burning Passion

As a child, have you ever held your index finger and thumb an arm length away in front of your eyes and aligned the gap between your fingers with the line of sight of your right eye so that it points towards one of the greatest, most magnificent, objects ever to be moulded by the hand of God; the stars. You squint and pinch that distant image to bring it closer to home, to bring it to your touch. You know that song? By The Beatles, who are stars in their own right. Lucy in the sky with Diamonds. Despite all its controversies, it still illustrates that innate dream of human beings to interact with the final frontier and unfold the mysteries of space.

What you might not know is our humble planet is bombarded by millions of pieces of space each day. Although most of them will vapourize as it enters our atmosphere, some actually make it onto our ground. We call these somethings, meteorites. Put a meteorite on your palm, and voila, you have just placed a piece of outer space in your hands. Cool right? Let’s learn more about these magnificent space rocks.

First of all, when people talk about shooting stars, they actually mean meteors... and meteors are most definitely not stars. So let me rephrase the title; The Fall of our Meteors. When asteroids collide with other extraterrestrial matter, such as other asteroids, smaller, though still considerably large pieces break off (<10 m across). These smaller but not so small space rocks are called meteoroids. As it comes knocking on Earth’s door, enters, and burns due to the friction caused by Earth’s atmosphere, they are called meteors. You may have seen quick streaks of light fly across the sky once, or if you’re lucky, multiple times. You know the ones you wish on? That light is caused by the burning of the meteors. Lastly, as mentioned previously, if the meteors were big enough to survive complete vapourization, they will finally arrive on earth as a meteorite waiting for someone, it could be you, to pick it up. Unfortunately, most meteorites fall into our oceans since 71% of our planet’s surface is covered in water. 

Now, for how meteorites are classified. Scientists group them based on what they are made of, their chemical composition and mineralogy. If they are made up of rocky silicate minerals, they would be called stony. If they are made of metallic material, they are iron meteorites. Then there are some with mixtures of the two; called stony-iron meteorites. 94% of meteorites are stony. Out of this 94%, 86% contain chondrules; small, round pieces of melted silicate minerals; they are called chondrites. Chondrites are about 4.55 billion years old. So, you think it’s cool to hold a dinosaur fossil because it is so old? Touch a chondrite and you would be leaving your fingerprint on something seventy times as old as the last dinosaurs; you would be holding what is known to be the building blocks of planets.Meteorites that were observed as they fall to the ground and later taken for research are called falls. If they were found without having observed the actual fall, they are called finds. 

Not all meteorites create giant craters; of course, not all of them all big enough to wipe out an entire race of species. Most of the time, small meteorites would fall at terminal velocity, and create small pits in the ground and small dents on roofs. But, yes, there are slightly more exciting meteors written in history. For one, the famous dinosaur extinction meteor, said to be six miles wide crashed into earth creating a crater 110 miles in diameter (believed to be in Yucatan, Mexico). To be clear, the dinosaurs didn’t die of the fire or sonic boom caused by the meteor crash. They died due to the disruption of the food chain as a result of the dust that blocked the sun for several months. Another meteorite that was about six miles wide created the largest impact crater on Earth; Vredefort dome; 186 miles wide 186 MILES WIDE!!!!! It is about 2 billion years old and it is located in South Africa. One that is closer to home, The ol’ Sudbury Basin; location: Greater Sudbury, Ontario. It is a crater that is home to 162,000 good folks. The crater contains a lot of copper. However, miners found that the crater contained a lot of nickel, which is more valuable. Today, 10% of the world’s nickel comes from the crater created by a giant meteorite 1.85 billion years ago. Thank you giant meteorite, for supplying our good society with some good nickel, and some great scientific knowledge.