If you are an astronomy enthusiast like many of us, you will probably remember that childhood event that started this exciting hobby for you. It may have been the first time you looked through a telescope. But for many of us, it was the first time we saw a rain of fire from the sky that we finally knew as a meteor shower.
The moment you see the first one, it’s easy to remember the movie “War of the Worlds” or some other fantastic image of aliens coming en masse into our atmosphere to take over the planet. But with a little guidance and explanation of what was happening, we eventually learned that these rains were by no means threatening or invasive of any kind. For the most part, meteor showers are harmless, a part of nature, and a lot of fun to watch.
So what are these strange lights in the sky? Are they aliens invading Mars? Are comets about to usher in the next ice age? Or maybe asteroids burn out when they enter Earth’s atmosphere. The answer to the previous questions is no to the first and “yes and no” to the other two.
A meteoroid is actually a small piece of space debris, usually dust or small rocks that come from a comet or asteroid that breaks through space and eventually crashes towards Earth. We say “down to earth” because the lights you see are the friction of the atmosphere that burns those little details of the space and creates a spectacular sight for all of us as they do it. A particularly exciting time to witness is when a meteoroid breaks or explodes upon entering. An exploding meteoroid is called a fireball.
There are some interesting details about the life of a meteoroid that make seeing shooting stars even more fun. To be seen, a meteoroid must weigh only one millionth of a gram. But what makes them so spectacular to see is the tremendous speed they reach as they enter the atmosphere. Before burning, a meteoroid will reach between 11 and 74 kilometers per second, which is 100 times faster than a high-speed bullet.
We tend to think of seeing a shooting star as a strange event and associate it with superstition (so I want a lucky star). But there are actually thousands of them every year, so it’s not that uncommon to see one. In fact, scientists tell us that more than 200,000 tons of space matter enters the atmosphere each year and burns when it enters.
Comets are a great source of meteoroids due to the nature of those long tails. A large amount of dust, ice, and other space debris is captured in a comet’s tail as it moves towards the sun. Then, as the comet moves away from the sun in its orbit, tons of this matter is thrown into space to disperse. As the Earth moves in its routine orbit around the Sun, it often passes through the clouds of this discarded matter which becomes one of those “meteor showers” that are so popular to see.
These shooting star showers are easy enough for astronomers to predict, so you can position yourself to see the excitement at the right time during the night and look at the correct area of the night sky. Usually the astronomy magazine or website will give you a general time and place to be ready to watch when the meteoroids start falling.
Now, keep in mind that this is a phenomenon of nature, so it may not be exactly on schedule. Also note that there is an annotation system for where the meteor shower will occur based on which constellation is your background. The section of the sky to focus on for the show is called the “radiant” because that is where the incoming meteoroids begin to glow or radiate. The radiant is also named after the constellation it is closest to. So, if the meteor shower occurs in the constellation of Leo, its radiant will be called Leonide. This will help you decipher the asteroid rain list in the posts.