Objective – Describe the characteristics of comets, asteroids, and meteors.
Space Object Differences
(source: Science Kids – Fun Science & Technology for Kids)
When learning about space it can sometimes be difficult to know the difference
between all of the amazing objects out there. The following terms are often confused
with each other so let’s answer the question: What’s the difference between a comet,
asteroid, meteoroid, meteor & meteorite?
Although there can sometimes be a blurry line between categories the following
definitions should help you understand the difference between comets and asteroids,
why Halley’s Comet is not a meteorite and more.
Comet
 A comet is a relatively small Solar System body that orbits the Sun. When close
enough to the Sun they display a visible coma (a fuzzy outline or atmosphere due
to solar radiation) and a tail.
Asteroid
 Asteroids are small Solar System bodies that orbit the Sun. Made of rock and
metal, they can also contain organic compounds. Asteroids are similar to comets
but do not have a visible coma (fuzzy outline and tail) like comets do.
Meteoroid
 A meteoroid is a small rock or particle of debris in outer space. They range in
size from dust to around 11 yards in diameter (larger objects are usually referred
to as asteroids).
Meteor
 A meteoroid that burns up as it passes through the Earth’s atmosphere is known
as a meteor. If you’ve ever looked up at the sky at night and seen a streak of light
that lasts one or two seconds, is called a “shooting star/falling star,” what you
are actually seeing is a meteor.
Meteorite
 A meteoroid that survives falling through the Earth’s atmosphere and colliding
with the Earth’s surface is known as a meteorite.
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Objective – Describe the characteristics of comets, asteroids, and meteors.
Asteroid Facts
(source: Science Kids – Fun Science & Technology for Kids)
Check out these asteroid facts. Enjoy a range of interesting facts about the Solar
System’s Asteroid Belt, the impact of potential asteroid collisions with Earth, theories
that suggest an asteroid led to the extinction of the dinosaurs and much more.
 Asteroids are small Solar System bodies that orbit the Sun. Made of rock and
metal, they can also contain organic compounds.
 Asteroids are similar to comets but do not have a visible coma like comets do.
 Asteroids are also known as planetoids or minor planets.
 Asteroids vary greatly in size, some feature diameters as small as 11 yards while
others stretch out over hundreds of miles.
 The first asteroid was discovered in 1801 by Italian astronomer Giuseppe Piazzi.
Named Ceres, it features a diameter of around 660 miles and is now regarded as
a dwarf planet. Ceres was given dwarf planet status in 2006.
 The Asteroid Belt lies between the orbits of Mars and Jupiter in the Solar
System. It is home to a large amount of irregular shaped asteroids that range in
size from dust through to the dwarf planet Ceres.
 It is believed by many scientists and researchers that an asteroid impact was the
cause behind the extinction of the dinosaurs around 65 million years ago.
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Objective – Describe the characteristics of comets, asteroids, and meteors.
Comet Facts
(source: Science Kids – Fun Science & Technology for Kids)
Enjoy these comet facts. Learn interesting info about Halley’s Comet, Shoemaker-Levy
9 (the comet that collided with Jupiter in 1994), what comets are made of, why they
have tails and lots more.
 A comet is a relatively small Solar System body that orbits the Sun. When close
enough to the Sun they display a visible coma and a tail.
 The coma is created as the comet gets closer to the Sun, causing water, carbon
dioxide and other compounds to vaporize (quickly changing from solid to gas)
from its surface.
 Comets are made of ice, dust and small rocky particles.
 The name comet comes from the Greek word meaning ‘hair of the head’, it came
from the Greek philosopher Aristotle who observed comets as ‘stars with hair’.
 Short term-comets have orbital periods of less than 200 years while long-term
comets have orbital periods of over 200 years.
Halley's Comet
 Halley’s Comet (or Comet Halley as it is also known) is the most well-known
comet.
 It is known as a short-term comet because the time it takes to orbit the Sun is
less than 200 years.
 Records of humans observing Halley’s Comet go back thousands of years, with
appearances noted by Babylonian, Chinese and European star gazers.
 It can be seen with the naked eye from Earth every 75 to 76 years (although the
time period has between 74 and 79 years in the past).
 It last appeared in the inner Solar System in 1986 and will return again sometime
in 2061 (start charging your camera battery).
 Halley’s Comet is named after English astronomer Edmond Halley who first
determined its period of orbit. It was the first comet to be recognized as having a
periodic orbit.
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Objective – Describe the characteristics of comets, asteroids, and meteors.
 Halley’s Comet appearance in 1986 allowed researchers to investigate its make up
more closely using spacecraft. While some previous theories were proven
correct, other models were altered with the new information.
 The fuzzy glow you see around Halley’s Comet is known as a coma. It occurs
when the comet gets close to the Sun and compounds such as frozen water and
carbon dioxide vaporize (rapidly change from solid to gas) from its surface.
 While the coma over Halley’s Comet can stretch up to 62,000 miles across, the
nucleus is actually small, only around 9 miles long, 5 miles wide and 5 miles thick.
Comet Shoemaker-Levy 9
 In July 1994, the Shoemaker-Levy 9 comet broke apart and collided with Jupiter.
This event gave astronomers a unique opportunity to observe what happens
when such a collision occurs.
 The largest fragments were around one mile in diameter and struck Jupiter at a
speed of around 11,000 miles per hour. The impact scars were clearly visible for
months after the impact.
 Shoemaker-Levy 9 was originally located by astronomers Eugene M. and Carolyn
Shoemaker and David Levy in March 1993.
Meteoroid, Meteor, and Meteorite Facts
(source: Science Kids – Fun Science & Technology for Kids)
Enjoy these great meteoroid, meteor and meteorite facts Learn the differences between
the terms used to describe them, how fast they travel, how often they make it through
Earth’s atmosphere and much more.
 A meteoroid is a small rock or particle of debris in our Solar System. They range
in size from dust to around 11 yards in diameter (larger objects are usually
referred to as asteroids).
 A meteoroid that burns up as it passes through the Earth’s atmosphere is known
as a meteor. If you’ve ever looked up at the sky at night and seen a streak of light
or “shooting star/falling star,” what you are actually seeing is a meteor.
 A meteoroid that survives falling through the Earth’s atmosphere and colliding
with the Earth’s surface is known as a meteorite.
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Objective – Describe the characteristics of comets, asteroids, and meteors.
 The fastest meteoroids travel through the Solar System at a speed of around
78,000 miles per hour.
 The Earth’s atmosphere experiences millions of meteors every day.
 Meteors are easier to see during the lower light conditions of night.
 A small percentage of meteoroids fly on a path that goes into the Earth’s
atmosphere and then back out again, they are known as Earth grazing fireballs.
 When many meteors occur in a close time frame in the same part of the sky it is
called a meteor shower.
 Around 500 meteorites reach the Earth’s surface every year but of those only
around 5 ever make it to scientists for study.
 Meteorites that are observed as they fall through the Earth’s atmosphere and
later recovered are called ‘falls’, all others are called ‘finds’. To this date there
have been around 1000 collected ‘falls’ and 40000 ‘finds’.
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Objective – Describe the characteristics of comets, asteroids, and meteors.
Name ______________________________________________ Score ________/14
Space Object Differences Worksheet – Worksheet
Match the Definition With the Term.
_____1. Asteroid
_____2. Comet
A. A small rock or particle in outer space; they range in size from dust
to around 11 yards in diameter.
_____3. Meteoroid
B. Burns up as it passes through the Earth’s atmosphere; looks like a
streak of light lasting one or two seconds.
_____4. Meteor
C. Relatively small Solar System body that orbits the Sun. When close
enough to the Sun they display a visible coma and a tail.
_____5. Meteorite
D. Small Solar System bodies that orbit the Sun; made of rock and
metal.
E. The small rock that survives falling through the atmosphere and
crashes on Earth’s surface.
Match the Term With the Statement. SOME CHOICES MAY BE USED MORE THAN ONCE.
_____6. 500 of these reach the Earth’s surface every year.
A. Asteroids
_____7. Are also called planetoids or minor planets.
B. Comet Halley
_____8. Called “stars with hair” by Aristotle.
C. Comet Shoemaker Levy 9
_____9. Collided with Jupiter.
_____10. Earth’s atmosphere experiences millions of these
every day.
_____11. Found between the orbits of Mars and Jupiter.
_____12. Made of ice, dust, and rocky particles.
D. Comets
E. Meteor
F. Meteorite
G. Meteoroid
_____13. Returns every 75 to 76 years
_____14. Some fly through the Earth’s atmosphere and back
into outer space.
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Objective – Describe the characteristics of comets, asteroids, and meteors.
Space Object Differences Worksheet – Key
D 1. Asteroid
C 2. Comet
A 3. Meteoroid
B 4. Meteor
E 5. Meteorite
F 6. 500 of these reach the Earth’s surface every year.
A 7. Aare also called planetoids or minor planets.
D 8. Called “stars with hair” by Aristotle.
C 9. Collided with Jupiter.
E 10. Earth’s atmosphere experiences millions of these every day.
A 11. Found between the orbits of Mars and Jupiter.
D 12. Made of ice, dust, and rocky particles.
B 13. Returns every 75 to 76 years.
G 14. Some fly through the Earth’s atmosphere and back into outer space.
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Objective – Describe the characteristics of comets, asteroids, and meteors.
Space Object Differences Worksheet – Scoring Guide
1. D (5 choices)
2. C (5 choices)
3. A (5 choices)
4. B (5 choices)
5. E (5 choices)
6. F (7 choices)
7. A (7 choices)
8. D (7 choices)
9. C (7 choices)
10. E (7 choices)
11. A (7 choices)
12. D (7 choices)
13. B (7 choices)
14. G (7 choices)
Scoring Guide
12-14 – 3
11 – 2 .5
9-10 – 2
8 – 1.5
6-7 – 1
1-5 – .5
0–0
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