Ever had the chance to make a wish on a shooting star? This
superstition originated around 2000 years ago in Ancient Greece, believed to be
gods peering down to Earth from the skies. Science has confirmed that falling
stars has nothing to do with the Olympian gods; this source of luck is a fiery
space rock falling into Earth’s atmosphere!
Our solar system is made up of planets, stars, asteroids,
comets, and meteoroids. Asteroids are huge rocks, ranging from 33 feet in
diameter to 329 miles in diameter, which orbit the sun and are often referred
to as minor planets. Meteoroids are small, rocky pieces broken off asteroids; a
meteor occurs when a meteoroid falls through Earth’s atmosphere, begins to
burn, and creates a streak of light across the sky! Meteors travel through our atmosphere
at tens of thousands of miles per hour, this intense speed causes the air in
front of the falling meteor to compress extremely quickly, creating immense
heat and burning the meteor. Stars are burning balls of gas which can burn to
up to 100,000⁰F (55,500⁰C), while meteors burn at around 3,000⁰F
(1,650⁰C)! Being that they are both blazing balls of fire, we can see how
meteors got the misnomer of “shooting star!”
It is easiest to view a meteor at night as they fall 34 to 70
miles above Earth’s surface. Meteors will typically disintegrate as they fall,
but sometimes survive the trip to the surface! Once meteors land on Earth’s
surface they are called meteorites. NASA has a large collection of meteorites,
compiled from around the world, which is used to learn more about the other
planets, asteroids and comets within our social system! By completing chemical
analysis on fallen meteorites, we have been able to determine the cause of the colors
you may see during a meteor shower! A red hue is cased by silicate, purple is
caused by potassium, green and blue is caused by copper, yellow by iron, and
yellow or orange is caused by sodium!
Meteors are often mistaken for comets. Comets are like asteroids
being that they are large bodies that orbit around the sun, expect comets are
composed of ice, gas and dust, nicknamed “dirty snowballs.” Comets are
extremely large and can be the size of a town while they are frozen, they are
believed to be left over pieces of material from when the solar system was
formed! As the comet’s orbit brings it nearer to the sun, the comet begins to
heat up, melt and burn, spewing its dust and gas into a giant, glowing tail;
this looks much like a falling meteor. Unlike meteors which are falling within
Earth’s atmosphere, comets are extremely far away from Earth! The burning tail
of a comment can be millions of miles in length and can be observed from earth
from over 70 million miles away! Halley’s Comet, the most famous of comets, can
be observed from Earth every 75 years, projected to return in the year 2061!
There are currently 958,714 known asteroids and 3,646 known
comments in our solar system. Of the almost million asteroids we have
identified, there are many smaller, broken meteoroids floating around in space.
Our planet is hit by 17 meteorites a day, with about 90-95% of meteors burning
up before they land on Earth’s surface. That makes about 6,100 meteors each
year! Celebrate Meteor Watch Day each year on June 30th with clear
skies and meteor showers!
Take a hands-on approach to learning about meteors on Meteor Watch
Day by doing the Crater Maker’s Experiment! https://sciencemadefun.net/downloads/crater_makers.pdf