The Amazing Universe

The Difference Between Meteoroids, Meteors and Meteorites.

The names meteoroids, meteors and meteorites can be confusing. I hope that this short article will explain how they differ.

My articles are not meant for people who have advanced knowledge of astronomy. The information in my articles has been gained by reading many books on the subject. I won't pretend to be an expert, but I hope you find some of my reads interesting.

Long before the Solar System existed there was an area in space that had a massive concentration of interstellar gas and dust, we know it now as a molecular cloud, this large area of space had a higher density than the surrounding areas.

Inside this cloud would eventually become the birthplace of our local star the Sun.

Extremely low temperatures caused the gas and dust to bond together, and these clumps grew larger as time went by. Then gravity started to pull the denser areas inward, this growing object was the beginning of a Protostar the early stage in the formation of a star.

Gravity continued to collapse the material into an object which was getting larger, hotter and denser, when a critical temperature of 15 million degrees Celsius was reached nuclear fusion took place in its core, and a main-sequence star was born, namely our Sun.

The Sun holds more than 99% of the total amount of mass in the Solar System.

The nuclear fusion process in the newborn Sun caused stellar winds to stream outward stopping more debris from falling in.

Circling the newborn Sun was the leftover material contained in a disc-shaped cloud called a solar nebula, it was inside this solar nebula where all the other celestial objects in the Solar System formed, like planets, dwarf planets, moons etc.

The Sun is estimated to be 4.6 billion years old, for all of that vast time smaller rocky, ice and metallic bodies called asteroids have circled the Sun.

Asteroids can sometimes collide with each other causing fragments to break away, it is these fragments that we call meteoroids. When icy comets come close to the Sun the heat can melt the ice dislodging small rocks which also become meteoroids.

Meteoroids can be as small as grains of sand and can reach 100 meters in diameter, bigger space debris are called asteroids.

Sometimes the Earth passes through an area in space that has a higher density of meteoroids, some can enter the Earth's atmosphere, when they do they are known as meteors. The smaller of them will burn up completely due to friction with the atmosphere. If the meteors are large enough, parts of them will land in the ocean or on dry land.

Objects that do land in the oceans or on land become meteorites. Over 90% of them are made of rock and the remainder consists wholly or partly of iron and nickel.

The largest meteorite ever found is the Hoba meteorite located in Namibia, this large chunk of iron is estimated to weigh over 60 tons.