CATCHING A FALLING STAR (OR METEORITE) - FIREBALL CAMERA NETWORKS IN THE 21ST CENTURY

摘要

Have you ever seen a shooting star? Have you ever seen a fireball? They are the spectacular fiery result when space dust and rocks enter our atmosphere. Meteors (also known as shooting stars) are specks of dust that leave a trail of light as they burn up in the atmosphere. Fireballs are caused by larger bits of material, making them significantly brighter, and can last several seconds in duration. Fireballs and meteors hit the atmosphere at velocities of tens of kilometres per second. Friction from the air heats the surface of the rock, melting and ablating it, giving the impression of a ball of fire. A meteorite is the surviving material from a fireball. Meteorites give planetary scientists information about the origin and evolution of the Solar System: from how the first solids formed all the way through to the accretion of planets. Meteorites provide a scientifically priceless record, but their impact is reduced because we have no spatial context to interpret their compositional data. Imagine trying to understand the geology of a continent if all you had to work with was a collection of random rocks dumped in your yard. That is where we are with meteorites. We know meteorites come from space, mostly from the asteroid belt. We can pinpoint their precise origin in the Solar System by determining the orbit that they were on before they hit our atmosphere. However, this is only possible if we are able to track the fireball before it lands. Combining the orbit with the recovered meteorite is a major step towards interpreting the record of early Solar System processes that meteorites contain.