Comets, Asteroids, and

Meteors

What  is a comet?A comet is a small

body which scientists

sometimes call a planetesimal. They

are made out of dust, rock, gas,

and ____. They are kind of like a dirty

_________.

snowball

ice

Comets are made up of different parts. The nucleus The coma

The ion tail The dust tail

The hydrogen envelope

The nucleus is the frozen _______ of a comet’s head. It is composed

of ____, ____, and dust. The nucleus contains most of the

comet’s mass and measure about 10 miles across or less.

centerice

gas

The nucleus of Halley’s Comet

The ______ is a spherical blob of gas that __________ the nucleus of a comet. As the comet gets closer to the sun, the heat __________ some of the ice

and causes the comet to spew gas and dust particles into space.

coma

nucleusThe_________and the _______ form

the head of a comet.

surrounds

vaporizes

coma

The _________ is made of ___________ charged gas molecules that are being pushed away from the nucleus by the

solar _____. (The blue tail in the picture.)

ion tail electrically

wind

When a comet is approaching the Sun, the ion tail _______ the comet: when the comet is leaving of the Sun, the ion tail

_____. The tail fades as the comet moves far from the Sun.

The ion tail can be

well over 100 million km long.

trailsleads

The _________ develops when the comet is _____ the

Sun. This tail is made of small dust particles that have

evaporated from the nucleus and are

being pushed away from the comet. The tail _______

slightly due to the comet’s motion.

dust tailnear

curves

The tail can be up to 250 million km long, and is

most of what we see.

Comets are only visible

when they're _____ the sun

in their elliptical orbits.

Comet Hale Bopp showing its two tails.

Courtesy of NASA

near

http://www.astrographia.com/images/9.jpg

Hale-Bopp – The Great Comet of 1997

Surrounding the coma is an

invisible layer of __________ that has been released. It

is the ___________________ . This cannot be seen from Earth because its light is absorbed by our atmosphere. It is usually between the ion tail and the

dust tail.

hydrogen

hydrogen envelope

Can you identify the following parts of a comet?

1.

2.3.

4.

5.

Ion tail

Nucleus

Coma

Hydrogen envelope

Dust cloud

Comets orbit the Sun in highly _________ orbits. Their speed _________ greatly when they are near the Sun

and ______ down at the far reaches of the orbit. Since the comet is light only

when it is near the Sun, comets are dark throughout most of their orbit.

ellipticalincreases

slows

Comets originate from either the _______ _____ (beyond the orbit of

Neptune) or the ___________ (which surrounds the outer reaches of the

solar system.)

KuiperBeltOort Cloud

http://videos.howstuffworks.com/hsw/5354-the-small-pieces-comets-video.htm

Videos on Comets

http://www.brainpop.com/science/space/comets/

http://www.kidsastronomy.com/comets.htm

Animation of a Comet

ASTEROIDS Asteroids are _______ or _________

objects, also know as____________ or minor planets that revolve around

our Sun.

rocky metallicplanetoi

ds

Most asteroids orbit the Sun in the asteroid belt located between

_______ and _________. A few asteroids approach the Sun more closely. The asteroids in the asteroid belt have a slightly __________ orbit.

JupiterMars

ellipticalThe time for

one revolution around the Sun

varies from about _________

Earth years3 to 6

Asteroids range in size from tiny pebbles to about 578 miles (930

kilometers) in diameter. Sixteen of the 3,000

known asteroids are over

150 miles (240 km)

in diameter.

• Asteroid Ceres• Diameter of

590miles (950 km)• Largest asteroid

and only dwarf planet in the inner

Solar System • Asteroid Vesta• Diameter of 326 miles (525

km)• Brightest

asteroid visible from the Earth.

Some asteroids even have orbiting ______. Here is the asteroid “243 Ida”

and its tiny asteroid moon, Dactyl. This is the first asteroid ever found

with an orbiting moon. Ida's dimensions are about 35 x 15 x 13 miles. Dactyl is only about 1 mile

across.

moons

METEOROIDS, METEORS, and METEORITES

Meteoroids are ______ bodies that travel through space. Most meteoroids are smaller than the size of a ________. Meteoroids are tiny particles left by an

asteroid or a comet.

pebble

small

A meteor is a meteoroid that has entered the _____________________,

usually making a fiery trail as it falls. It is sometimes called a _________ star or

a _______ star.

Earth’s atmosphere

shooting falling

A meteor shower is a phenomenon in which ______ meteors fall

through the atmosphere in a relatively ______ time and in

approximately parallel trajectories.

Arizona, November 1966 - The Leonid meteor shower rained 2,300 meteors per

minute for 20 minutes. (Photo NASA)

manyshort

http://www.metacafe.com/watch/903546/time_lapse_of_the_perseid_meteor_shower_geminid/

Video of meteor Shower

A meteorite is a meteor that has fallen and ______ the Earth. These rare objects have survived a fiery fall

through the Earth's atmosphere and have lost a lot of mass during that

process.

struck

Animation on the formation of this crater. http://www.meteorcrater.com/

Near Winslow, Arizona, you can visit a crater that was made from a meteorite. The crater is nearly one mile across, 2.4

miles in circumference, and more than 500 feet deep.

http://www.kidsastronomy.com/images/comet2.gif

http://www.kidsastronomy.com/comets.htm

http://www.nasa.gov/worldbook/comet_worldbook.html

http://www.explanet.info/Chapter14.htm

http://ed101.bu.edu/StudentDoc/Archives/spring05/aprylh/Lesson1.html

http://spaceinimages.esa.int/Images/2002/11/The_nucleus_of_Comet_Halley

http://studentastronomyblog1.blogspot.com/2013/02/dirty-snowballs-comets.html

http://science.howstuffworks.com/dictionary/astronomy-terms/comet3.htm

http://spaceplace.nasa.gov/tails-of-wonder/

http://www.thegalaxyguide.com/galaxy/comets/

http://spaceguard.rm.iasf.cnr.it/NScience/neo/neo-what/com-tail.htm

http://www.astropix.com/HTML/SHOWCASE/970401.HTMhttp://www.solarviews.com/eng/comet.htm

http://blogs.saschina.org/julia01pd2014/2010/03/10/lab-answers/

http://www.enchantedlearning.com/subjects/astronomy/activities/label/comet/

http://cse.ssl.berkeley.edu/segwayed/lessons/cometstale/frame_orbits.html

http://abyss.uoregon.edu/~js/images/migrate3.gifhttp://csep10.phys.utk.edu/astr161/lect/asteroids/features.html

http://en.wikibooks.org/w/index.php?title=File:Asteroid_belt_between_Mars_%26_Jupiter.PNG&filetimestamp=20050718221323&

RESOURCES

http://www.sen.com/feature/space-rocks-comets-asteroids-meteorites-and-more.html

http://dustyloft.files.wordpress.com/2008/09/asteroids_comets_sc_0-000-075.png

http://en.wikipedia.org/wiki/Ceres_(dwarf_planet)

http://en.wikipedia.org/wiki/File:Meteoroid_meteor_meteorite.gif

http://rense.com/general42/ukteen.htm

http://weblogs.marylandweather.com/2010/01/twilight_meteor_reported_monda.html

http://science.howstuffworks.com/dictionary/astronomy-terms/leonid2.htm

http://www.meteorcrater.com/