Transcript The Asteroid Belt

Asteroids
Asteroid Belt
• An asteroid is a bit of rock
• Left over after the Sun and all the planets were
formed.
• Most asteroids in our solar system can be found
orbiting the Sun - between the orbits of Mars and
Jupiter
• Known as the asteroid belt
The Asteroid Belt
Ceres
• Largest asteroid
found (so far) in the
asteroid belt is as big
as the state of Texas
– Named Ceres.
Asteroid Belt
Asteroid Belt
• Think about it this
way:
– The asteroid belt is a
big highway in a
circle around the
Sun.
– asteroids are cars on
the highway.
• Sometimes, the
asteroid cars run into
one another
– Asteroids may break
up into smaller
asteroids
– Scientists think that
most asteroids are the
result of collisions
between larger, rocky
space bodies.
• Asteroids can be a
few feet to several
hundred km’s wide
• The belt contains at
least 40,000 asteroids
that are more than 2
km’s across
http://news.discovery.com/videos/space-doomsday-asteroid.html
Meteoroids
(meteors and meteorites)
Using Meteorites
• In Greenland, people
dig up meteorites and
use the iron in them
to make tools.
METEOROIDS
• A piece of stone- or
metal-like debris which
travels in outer space.
• Most meteoroids are no
bigger than a pebble.
– Large meteoroids are
believed to come from
the asteroid belt.
Meteors
• Smaller meteoroids may have come from the
Moon or Mars.
• If a meteoroid falls into the Earth's atmosphere,
it will begin to heat up and start to glow. This is
called a meteor.
Falling Stars
• If you have ever seen
a "falling star", you
were actually seeing
a meteor
Meteorite
• Most of the original
meteor burns up
before it strikes the
surface of the
Earth
• Any leftover part
that does strike the
Earth is called a
meteorite
Craters
• A meteorite can make
a hole, or crater, in the
ground when it hits it
• The larger the
meteorite, the bigger
the hole
http://videos.howstuffworks.com/tlc/30766-understanding-meteor-crater-in-arizona-video.htm
Perseid Meteor Shower
http://vimeo.com/14133160
Comets
Comets
• Comets are made up of
material left over from when
the Sun and the planets
were formed
• About 100 billion comets
orbit the Sun
– Some comets orbit the Sun like
planets.
Comets
• Comets are made of dirty ice, dust, and gas
• When a comet gets close to the Sun, part of the ice
starts to melt
• Solar winds push the dust and gas released by the
melting ice away from the comet.
– Forms the comet's tail. Every time a comet comes close
to the Sun, a part of it melts.
– Over time, it will completely disappear.
Comets
• A comet does not give
off any light of its own.
– Light is actually a
reflection of our Sun's
light
– Sunlight bounces off the
comet's ice particles in
the same way light is
reflected by a mirror.
Halley's Comet
• A few comets come
close enough to the
Earth for us to see
them with our eyes.
Halley's Comet, for
example, can be seen
from Earth every 76
years.
http://www.videopediaworld.com/video/34929/Comets-Halleys-Comet
HALLEY’S COMET
Halley's Comet Statistics
Perihelion distance: 0.587 AU
Orbital eccentricity: 0.967
Orbital inclination: 162.24°
Orbital period: 76.0 years
Next perihelion: 2061
Diameter: 16 x 8 x 8 km
HALLEY’S COMET
Close approaches to Earth
0.19 AU from Earth on 1835 October 13
0.15 AU from Earth on 1910 May 20
0.42 AU from Earth on 1986 April 11
0.48 AU from Earth on 2061 July 29
THE END!