Laymans Guide to the Difference between Meteorites and Asteroids

Along with the many other natural objects traveling through the solar system with planet Earth, asteroids and meteorites share some new notoriety due to their numbers and an increased focus by the National Aeronautics and Space Administration (NASA).  Described bluntly, this interest is more than mere scientific curiosity; it places public emphasis on measures designed to protect the people of this planet from death secondary to any impact by space objects.

Simple light shows

People sometimes think of meteorites as both streaks in the night sky and rocky or metallic debris found after a suspected impact.  In most cases, these are different classes of object because meteors don’t impact the ground, and meteorites are only the survivors of such impacts.  The “ite” suffix indicates that a meteor has not only been heated to incandescence by its passage through Earth’s atmosphere, but that something survived both the devastating heat and the impact and was found at a later time.

Asteroids, on the other hand, are usually not seen by anyone until they become of interest for some scientific or security reason. “[A]steroids, or impactors that broke them apart, are usually very small.”  They are called planetoids or minor planets, because they show no disk and are not volatile like comets, which may be of similar size.  In an age of economic insecurity and hardship, NASA and others have looked at asteroids as resources for space mining due to the high probability they will contain useful ores.  Some asteroids have prompted attention for other reasons.

Close approach

A couple of asteroids have come very close to Earth and the Moon in the recent past.  Though they did not impact either body, they brought home to observers the knowledge that danger could come undetected from deep space if sky watchers all over the world fail to see large, closely approaching space objects.  Some asteroids are small, but there are many varieties of shapes and sizes among asteroids.  It is in the best interest of Earth’s astronomers, professional and amateur, to watch closely for any more close encounters, keeping in mind the extinction-level event 65 million years ago that ended the reign of the dinosaurs.  This is exactly what is on the minds of a group seeking approval for the “2017 launch of a private space telescope dedicated to seeking out potentially dangerous space rocks.”

Asteroids and meteorites are normally only fascinating objects of study.  It may be that NASA or some other governmental agency will someday soon find a way to harvest larger asteroids for basic materials.  Given the frequency of meteor sightings, perhaps enough attention will be brought to bear so that telescopes all over the world will effectively monitor their movements and warn of anything that is more than a pretty streak in the night sky, in time to make a difference to those in its path.