A “falling star” is a common term for a meteor, which is not a star. It is a streak of light observed when a small piece of space rock, a meteoroid, enters Earth’s atmosphere. Friction from its rapid passage through the air causes the meteoroid to heat and burn, creating a luminous trail. These events typically occur in the mesosphere, 76 to 100 kilometers (47 to 62 miles) above Earth’s surface.
How They Appear
Meteors vary in visual characteristics as they streak across the night sky. Their brightness varies significantly, from faint flashes to exceptionally bright fireballs that can even outshine Venus. The color of a meteor depends on the chemical composition of the meteoroid and the gases in the atmosphere. Sodium produces orange-yellow light, iron appears yellow, and magnesium often results in a blue-green hue. Nitrogen and oxygen contribute to red light, while calcium may create a violet glow.
These streaks move quickly, typically between 40,000 and 257,000 kilometers per hour (25,000 to 160,000 miles per hour). They often move across the sky rather than falling straight down, and their flight usually lasts only a second or two. A bright meteor might create a sonic boom if large enough to penetrate lower atmospheric layers, but most do not produce audible sounds because they burn up at high altitudes.
Telling Them Apart From Other Objects
Meteors are distinguished from other celestial or atmospheric phenomena by their unique movement and light patterns. Airplanes typically display steady or blinking lights and move much slower, often showing dotted patterns from navigation lights. Satellites appear as steady, often dim, solid lines of light that glide silently and slowly, reflecting sunlight rather than burning up. They can be visible for several minutes or across multiple frames in photographs.
Stars and planets remain stationary points of light, though stars may twinkle. Unlike meteors, which are fleeting streaks of light, these objects do not move noticeably in a short observation period. By observing speed, duration, and light characteristics, one can differentiate a rapidly burning meteor from other common aerial sights.
Tips for Spotting Them
To increase the chances of witnessing a meteor, find a location away from city lights and allow eyes to adjust to darkness for at least 20 minutes. Patience is beneficial, as meteors are unpredictable. While meteors can appear any night, specific times of the year, known as meteor showers, offer increased activity when Earth passes through comet debris trails. Observing after midnight often provides the best viewing, as your location on Earth faces the oncoming meteor stream.