Comets, Meteors, and Asteroids Oh My!!

Terms:

CometComa

NucleusTail

MeteorMeteoroidMeteoriteAsteroid

S6E1.f Describe the

characteristics of comets,

asteroids, and meteors

• In the distant parts of our solar system, comets are dust covered balls made of ice and rock

• These dust covered balls of ice and rock are called a nucleus

• Something disturbs the comets and sends them streaking toward the sun!

• As the nucleus passes the orbit of Jupiter, it begins to heat up.

• Some of the ice inside the nucleus turns to glowing gas

• The gasses spread out from the nucleus to form an atmosphere around the nucleus called a coma

• Together, the coma and the nucleus form the head of the comet

• As the comet approaches the sun, energy from the sun blows parts of the coma away from the nucleus…..

<Show Them>

• These parts stream away from the head of the comet to form a shimmering tail

• A comets tail ALWAYS points away from the sun

Nucleus

Coma

Tail

Head

• Some comets plunge into the sun, and others orbit around the sun one or more times

• The most famous returning comet is Halley’s Comet, which comes back approximately every 76 years

• Can you see where the nucleus, coma, and tail are?

• Judging from this picture, where is the sun?

Asteroids

Asteroids are chunks of rock and metal, much smaller than Earth’s moon

• Asteroids orbit the sun like planets

• Most asteroids are found in a belt between the orbit of Mars and Jupiter

• The largest known asteroid is Ceres (940 km in diameter)

• Most asteroids are less than 1 km in diameter

Meteoroids, Meteors, and Meteorites

• Between 1,000 and 10,000 tons of space rock fall to Earth each day…… when it is in space these rocks are called meteoroids

• Meteoroids are made of

rocky materials, and metal

• When a meteoroid plunges into Earth’s atmosphere it is known as a meteor

• In Earth’s atmosphere, the meteor can get so hot that some or all of it burns up.

• The burning meteor

appears as a streak of light ……

A Shooting Star

• If a meteor does not completely burn up in our atmosphere, it will hit Earth’s surface.

• When a meteoroid hits Earth’s surface it is known as a meteorite

Worlds largest meteorite Hoba, found in Namibia

Draw the sequence that a meteoroid goes

through……….

Quick Check

In which direction does a comets tail always face?

a. In the direction of the sun

b. Away from the sun

c. Perpendicular to the sun

d. All different directions

Quick Check

What is a comets coma?

a. The stony and icy center of the head

b. A chunk of iron

c. A stream of gas at its back

d. The atmosphere around its nucleus

Quick Check

Where are most asteroids found?

a. All over our solar system

b. In orbit between Mars and Jupiter

c. Near Earth

d. Outside of the solar system

Quick Check

What is the sequence that describes a space rock that falls to Earth’s surface?

a. meteoroid, meteor, meteorite

b. Meteor, meteoroid, meteorite

c. Meteorite, meteor, meteoroid

d. Meteor, meteorite, meteoroid