What Is a Shooting Star?

Step 1 of 5

It is a speck, not a star.

The average shooting star is a piece of grit the size of a grain of sand. A real star is a ball of fire a million kilometres wide.

Step 2 of 5

Space is full of leftover crumbs.

Comets shed dust as they orbit, and old collisions left rubble everywhere. Earth ploughs through this debris constantly as it circles the Sun.

Step 3 of 5

They arrive shockingly fast.

A meteor hits the top of our air at 40 to 70 kilometres per second — around a hundred times faster than a bullet.

Step 4 of 5

The air in front is crushed and glows.

It is not friction. The rock rams air so fast that the air cannot get out of the way, gets violently squeezed, and squeezing gas makes it blisteringly hot.

Step 5 of 5

Almost all of them are gone in a second.

The speck vaporises about 80 km up. Only rare, bigger lumps survive to reach the ground — and then we call them meteorites.

Meteor showers happen when Earth crosses a comet's old dust trail at the same point every year.