Objective – Using references, compare the physical properties of the asteroids, comets, meteoroids, meteors, & meteorites.
Asteroids
Composition
Locations
Distance from Sun
Number
(millions of miles)
Rocky bodies
Most found between orbit of Mars and
Jupiter; are also found between Mars and the
Sun.
Size Range
Most asteroids are
between 186,000,000
miles to 300,000,000
miles.
Shape
How Seen
From pebbles to 544 miles. Irregular to almost round.
150,000,000 (larger than 100 meters)
Two Largest*
Cannot be seen without a telescope. Pallas – 540 miles
Vesta – 524 miles
*Ceres was the largest asteroid. In 2006, Ceres was classified a dwarf planet.
Main Asteroid
Belt
1
Objective – Using references, compare the physical properties of the asteroids, comets, meteoroids, meteors, & meteorites.
Meteoroids/Meteors/Meteorites
Where They Come
Size Range
From
Definition of a
Definition of a Meteor
Meteoroid
Most come from particles
in the Asteroid Belt.
A few come from particles
left from comets when
Earth crosses their path.
Meteor
Iron Meteorite
Grain of sand to
a round around
10 yards across.
Meteorite
Grain of sand or rock Grain or rock that has
that is travelling in
entered the atmosphere
space.
(sometimes called
“shooting” or “falling”
star.)
Meteoroid
Stony Meteorite
2
Definition of a
A meteor that is large
enough to survive the
trip through the
atmosphere and hit the
Earth’s surface.
Meteor
Iron Meteorite
Objective – Using references, compare the physical properties of the asteroids, comets, meteoroids, meteors, & meteorites.
Comets
Composition
Water ice, dry ice, ammonia ice, dirt, and
rocks. Are also called “dirty snowballs”
or “icy dirtballs.”
Number
Unknown. Estimated to be over one
trillion.
How Seen
Some comets are bright enough to be
seen without a telescope. A telescope is
needed to see most comets.
Parts of a Comet
Nucleus
Coma
The actual comet; the “dirty snowball.”
Gases that vaporize and surround the
nucleus as the comet gets close to the
Sun.
Tail
Made of dust particles and gases pushed
away from the comet by the solar wind;
always points away from the Sun.
Coma
Nucleus
Tail
3
Objective – Using references, compare the physical properties of the asteroids, comets, meteoroids, meteors, & meteorites.
Where Comets Begin Their Journey
Kuiper Belt
Where Found
Distance From Sun
Number
Size
(miles)
Outside of Neptune’s Closest – 2,790,000,000
orbit
Farthest – 4,650,000,000
Note – Kuiper Belt objects cannot be seen without a telescope.
Where Found
Period (One
orbit of Sun)
> 1,000,000,000,000,000
Small chunks to 62
miles across.
< 200 years
Size
Period (One
Oort Cloud
Distance From Sun
Number
(miles)
orbit of Sun)
Border of Kuiper
Closest – 186,000,000,000
> 2,000,000,000,000,000 (?)
Belt to 1 light year.* Farthest – 6,000,000,000,000
Note – Oort Cloud objects cannot be seen.
*A light year is the distance light travels in one year – 6,000,000,000,000 miles (six trillion).
(source: American Museum of Natural History)
4
Small chunks to 62
miles across.
> 200 years