Meteoroids, Asteroids Dwarf Planets The Small Stuff Meteoroids, Asteroids Dwarf Planets And Comets

Five types of objects orbit the Sun: Planets, that have enough mass (and thus gravity) to… be spherical clear their orbits of other objects of similar size. They are also “differentiated” or layered Dwarf Planets, that have enough mass (and gravity) to… But not enough to clear their orbits 3. Comets, Icy objects that melt as they near the Sun forming “tails” 4. Minor Planets or Asteroids, rocky objects that have too little mass to make themselves spherical. 5. Meteoroids, even smaller rocky objects

Meteoroids, Meteors & Meteorites Meteoroids often have orbits that cross that of Earth. When they are in space they are called Meteoroids When they fall through the atmosphere they heat up and glow… A “falling star” or Meteor The largest meteors are known as “Fireballs” Most burn up before they hit the surface. Those that hit the Earth (or other planet or moon) are called Meteorites

Three Kinds of Meteoroids Meteoroids are divided into three kinds by content: Iron, made of metal, mostly iron-nickel. Stony, made of silicates Stony-Iron, of mixed composition

Chondritic Meteoroids Most stony meteoroids are made of smaller rounded chunks called chondrules These “chondritic” meteoroids are 4.5 billion years old. They probably are some of the first objects to condense out of the solar nebula

Carbonaceous Chondritics Some chondritic meteoroids have a high carbon content. These carbonaceous chondritic meteoroids often contain organic compounds including amino-acids! So the building blocks of proteins and thus life have been around since before the solar system formed.

Origin Most meteoroids are fragments of asteroids or comets. Some have been blasted off of planets or moons during collisions. Some may have condensed in the early solar system and just never became part of a larger object.

Meteor Showers Meteors fall toward Earth all the time. However Most meteoroids orbit in groups. Meteoroids that came from comets often orbit in groups near the path of the comet’s orbit. When the Earth passes through one of these “clouds” of meteoroids the number of meteors per hour goes up significantly A Meteor “Shower” They are predictable. And are named for the constellation they seem to come from