Imagine stargazing on a clear moonless night. Suddenly, a bright flash of light appears up in the sky. Is it a bird, is it a plane, or is it your favourite superhero? Chances are, it's neither of those things, but you might have just seen a shooting star.
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These natural astronomical phenomena, also known as meteors, are rather elusive.
But just like the Southern Lights, they never fail to amaze us with their splendour when it happens.
Meteors are caused by pieces of space rock entering the atmosphere and being heated up due to friction. When they arrive in large numbers, they are usually known as meteor showers.
They may seem big, but they are often the size of grains of sand. They usually come from comets, like Halley's Comet, which leave behind a trail of dust particles.
On very rare occasions, larger pieces of space rock may enter the atmosphere, causing "fireball" meteors bright enough to even cast shadows on the ground.
We can tell when meteors would occur based on when the Earth would intercept the path of the comet. During a meteor shower's peak period which only lasts about 1-2 days, the maximum number of shooting stars observed can go up to a few hundred on very clear dark nights.
Not all shooting stars look the same. The colour and the length of its streak differ based on the size of the particle as well as its chemical composition.
For example, a violet meteor indicates the presence of calcium while a green one indicates the presence of nickel. Sometimes, a meteor may even appear red thanks to the nitrogen and oxygen molecules that are super-heated in our atmosphere.
The best way to see them is in an open space with a good view of the night sky during one of the meteor shower periods.
But of course, it goes without saying that the less light pollution in the sky, the darker it will be, resulting in a larger number of shooting stars observed as compared to a more light polluted one.
The moon is a great contributor to light pollution as well. To maximise the number of meteors seen, you should choose a date and a time that the moon will be below the horizon.
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As we draw towards the end of the year, the two meteor showers to look out for of are the Leonids (November 17-18) and the Geminids (December 13-14). These meteor showers are named after the constellations they seem to originate from, also known as the "radiant".
I recall observing my first meteor shower (Geminids) when I came to Australia in 2012, and I can still fondly remember how amazed my siblings and I were after seeing so many flashes of light appearing out of nowhere in the sky.
Hence, if you have never seen one before, now is your turn to do so.
- Wei Shen is a PhD student at the ANU Research School of Astronomy and Astrophysics. His research focuses on the chemical composition of stars in nearby dwarf galaxies.
