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How Do Meteors Glow?

Meteoroids are small pieces of debris in space that usually come from interplanetary collisions, dust particles from asteroids or comets that disintegrate. When they enter the earth's atmosphere, they become meteors, glowing streaks of light sometimes known as shooting stars. The streak of light makes them appear larger than the dust to pebble size particles they actually are. According to the American Meteor Society, meteors were thought to be an atmospheric phenomena until the mid 1800s.

Cause
- Some meteors are made of stony or metal particles, while most are made of dustballs. Meteors enter the upper part of Earth's atmosphere at speeds up to 72 kilometers per second, reports the Astronomical League. The friction between the meteoroid and the atmosphere cause the glowing streak of light that begins almost as soon as they meet, according to Earth Sky. According to NASA, the collision between the particles and air molecules create a vapor of sodium, iron and magnesium atoms that emit light when the electrons fall back into a resting position. Some meteors burn up soon after they enter the atmosphere, while others fall farther before they heat up enough to glow.
Size and Speed
- Larger meteors do not cause a more persistent glow; according to the American Meteor Society, it is the kinetic energy produced by the friction of the fast-moving particles as they come in contact with the Earth's atmosphere. The collision of the meteoroid with air molecules causes atoms in the atmosphere in its path to create a long, thin flash of light. The American Meteor Society says the Earth's rotation around the sun causes evening meteoroids to enter the atmosphere at lower speeds than those just before sunrise, leading to brighter flashes of light in meteors spotted just before daylight. When larger meteoroids make it through the atmosphere and land on Earth, the remnants are known as meteorites. Though the Astronomical League states larger meteroids are rare, winds high in the atmosphere can distort their path when they occur, leaving a strange shaped trail of smoke. Since
Wake
- According to the National Aeronautics and Space Administration (NASA), brighter meteors that enter Earth's atmosphere at high speeds can leave persistent glows. The brief glow behind the head of the meteor lasting between one and ten seconds is called the wake. NASA states the wakes are caused by green light of neutral oxygen atoms.
Afterglow and Persistent Train
- Afterglow is the glow atoms emit in the path of very bright meteors known as fireballs. Persistent train is the long lasting glow that stays in the path of a fireball for one to thirty minues after the afterglow has faded. These trains are caused by the sodium and iron oxide in oxygen atoms and ozone molecules, according to NASA, and most persistent trains last four to six minutes

Astronomy