Meteor Watch Day will be here soon, so get ready to impress your fellow watchers with these fun facts about our favorite nighttime attraction and enjoy the fun!
Meteor Watch Day: Get Ready!
Meteor Watch Day will take place on June 30, 2017, but if you can't wait for the show to begin, you can tide yourself over with a few fun facts to amaze your students. Learn the difference between a meteor and meteorite, what's up with the lights we see shooting through the night sky, and what those different colors mean as they brighten your night.
Meteor vs. Meteorite
Okay, so what's the difference between a meteor, a meteorite, a meteoroid, a comet, and an asteroid? According to Hubblesite, a meteoroid is a piece of space debris smaller than a kilometer (0.62 miles) in size. Larger pieces of rock originating from the asteroid belt between Jupiter and Mars are known as asteroids.
When a meteoroid enters the Earth's atmosphere, it causes a flash as it burns. This flash of light is called a meteor. If any piece of the debris makes it to the planet's surface, we call it a meteorite. It's uncommon for this to happen, and the pieces of debris are usually small, with exceptions. The largest reported to date, the Willamette Meteorite, was located in West Linn, Oregon, in 1902 and weighed in at 16 tons!
Comets are similar to asteroids in that they are large pieces of natural space debris. They're typically made up of rocks, frozen water, gases such as methane and ammonia, along with other materials. Comets can develop a shell around them called a coma, which along with the tail, is visible when they come close to the sun. They do on occasion make themselves visible in the night sky and follow regular paths that bring them close to Earth at predictable intervals, such as Halley's Comet, which we see about every 75 years.
Real Scoop on Wishing Stars
For hundreds of years, perhaps longer, meteors have been colorfully referred to as shooting stars, but stars they are not. Those streaks we see lighting up the sky are really just dust and small pebbles burning up in the Earth's atmosphere.
So, why would anyone believe they could grant wishes?
At least as far back as the time of the Greek astronomer and writer Ptolemy (100-168 A.D.), people have wished upon these falling bodies. This odd belief may have developed because the ancient astronomer thought the flashes were caused by the gods peeking in on man, thereby making the stars fall out of the sky. People believed that, since the deities were already paying attention, they might be more easily persuaded to grant a favor or two.
Always Falling, but Not Always Visible
While it's easier to see meteors at night, the truth is that they fall all the time; we just can't always see them in the daytime. If you're set on watching meteors light up the night sky, choose a dark, moonless night in a place far away from the light pollution of densely populated areas.
Meteor showers do occur with some regularity as the Earth passes through the tails of comets with regular orbits around the sun. Some of the best for amateur viewing include the Leonids (November), Perseids (August), and Geminids and Ursids (December).
Impact of Asteroids
While most space debris burns up in the Earth's atmosphere, occasionally large pieces do make landfall and cause a lot of damage. The biggest pieces can carve craters 10-20 times their original size and leave quite an impression on the planet. Among the largest craters known to man are the 300-kilometer-wide Vredefort Crater in South Africa; the Sudbury Basin in Ontario, Canada, measuring about 130 kilometers in diameter; and the Acraman Crater in Australia that geologists estimate was between 90 and 150 kilometers in diameter.
These collisions can do more than leave a mark on the land, they can change the entire face of the planet if they're big enough. Many scientists believe that a major asteroid impact caused the global catastrophe that killed the dinosaurs about 65 million years ago. Geological evidence shows that a meteor roughly six miles across crashed down in what is now the Yucatan Peninsula in Mexico. Evidence suggests that the force of the resulting explosion threw burning debris several miles into the atmosphere. When the debris fell back to Earth, it ignited massive fires and created a dust cloud that so disrupted the food chain and environment, it was virtually impossible for the massive creatures to survive.
Meteor Identification Guide
Meteoroids aren't just made up of dirt and rock; most carry with them a variety of different minerals that can cause them to glow white, red, orange, green, and even blue as they enter the atmosphere. These dancing colors are due to the unique chemical composition of these minerals, which burn at different temperatures and emit differing colors as they do so.
If you would like to identify the makeup of the meteor shower you're watching, here's a handy guide:
- If a meteor is made of calcium, expect to see a purple glow.
- Magnesium-heavy meteors glow blue.
- Meteors made of oxygen and nitrogen will appear red.
- Iron-based meteors show up yellow.
- Meteors with high sodium levels burn orange.
Of course, mixtures of elements are possible and can create a rainbow of different hues as they brighten the evening sky.
While some meteors do reach the surface of the Earth and cause damage, most burn up and give off nothing more than a thrilling glow. Do you have a favorite spot to watch the night sky? Has anything extraordinary happened to you while you were exploring the universe with your telescope? Let us know how you plan to take advantage of the good weather and create summer memories this June while enjoying Meteor Watch Day!