tähdenisku

Tähdenisku is the Finnish word for a meteor, commonly referred to as a shooting star. It describes the visible streak of light that appears in the night sky when a meteoroid enters the Earth's atmosphere and burns up due to friction. Meteoroids are small rocky or metallic bodies in outer space, typically ranging in size from dust grains to small asteroids.

When a meteoroid encounters Earth's atmosphere, the immense speed at which it travels causes the air molecules around it to heat up significantly. This intense heat causes the meteoroid and the surrounding air to glow, creating the luminous trail we observe. Most meteoroids that cause tähdeniskut are very small, often no larger than a grain of sand. Larger objects can create brighter and longer-lasting meteors, sometimes referred to as fireballs.

The phenomenon of tähdeniskut has captured human imagination for centuries, often associated with wishes and omens. They are a regular occurrence in the night sky, with many visible every hour, especially during annual meteor showers like the Perseids in August or the Geminids in December. These showers happen when Earth passes through the debris trail left behind by comets or asteroids. While most tähdeniskut burn up completely before reaching the ground, a rare few that survive the atmospheric passage and land on Earth are called meteorites.