Why do shooting stars only last a second?
Shooting stars are made by tiny specks of dust that move so fast through our air that they burn away almost instantly.
A shooting star flashes across the sky and is gone before you can say 'Look!' Why so quick?
The answer is speed. The specks of dust that make shooting stars are travelling incredibly fast, between about 11 and 72 kilometres every second. At the fastest speeds, they could cross the whole of Britain from south to north in under 20 seconds. When something that fast hits the air, it squashes the air in front of it so hard that it gets extremely hot. The heat makes the dust, which is usually smaller than a grain of rice, melt and turn to gas. Because it is so small, it is used up in a fraction of a second.
Bigger pieces of space rock last longer, perhaps several seconds, and make brighter streaks called fireballs. Very rarely, a fireball is big enough that part of it survives, slows down and falls to the ground as a meteorite.
The colour and length of a shooting star can tell scientists about its speed and what it is made of. Faster meteors tend to be brighter and sometimes leave a glowing trail that lingers for a moment after the meteor itself has gone.