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Meteoroids! Asteroids! Comets!

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Title: Meteoroids! Asteroids! Comets!


1
Meteoroids! Asteroids! Comets!
  • Oh, my!

2
What makes up our Solar System?
  • The sun
  • Planets
  • Moons
  • Asteroid belt (between Mars and Jupiter)
  • Lots of space
  • All sorts of bits and pieces of rock

3
Meteorite, Meteoroid, Meteor? Whats the
difference?
4
Meteorite vs. Meteoroid
  • Meteoroid while in space a meteorite is called
    a meteoroid
  • Meteorite a small rock or rocky grain that
    strikes Earths surface
  • So the difference is just based on where the rock
    is when you are describing it

5
Meteor
  • Sometimes called a Shooting Star
  • When a meteorite enters Earths atmosphere,
    friction causes them to burn up, producing a
    streak of light

6
Where do they come from?How big are they?
  • Pieces of rock that broke off other objects
  • Sizes range from as small as a pebble or as big
    as a huge boulder

7
Are they dangerous?
  • Most meteoroids disintegrate before reaching the
    earth by burning up in Earths atmosphere
  • Some leave a trail that lasts several minutes
  • Meteoroids that reach the earth are called
    meteorites. Large ones can cause damage

8
Flagstaff, Arizona
  • 49,000 years ago
  • Meteorite about 150 feet in diameter
  • Weighed 650 pounds
  • Energy 2.5 million tons of dynamite
  • 4000 feet wide, 650 feet deep
  • Still visible today

Barringer Meteorite Crater
9
Whats a Meteor Shower?
  • Usual rate six meteors per hour
  • During a Meteor Shower rate may be as high as
    60 meteors per hour
  • Occur when Earth passes through the tail or
    debris of a comet
  • Presides (mid-August)
  • Leonids (mid-November)

10
Comets
  • Bodies in space made up of ice, dust, small
    gritty particles
  • Sometimes called dirty snowballs
  • When close to the sun, ice vaporizes, producing a
    spectacular streak of gas, referred to as a
    tail
  • Many in a regular orbit around the sun

11
Comets
12
Where do comets come from?
  • Many ordinate in a region called the Oort cloud
    which is located beyond the orbit of the dwarf
    planet Pluto
  • Others originate in the Kuiper Belt beyond the
    orbit of Neptune
  • This region is filled with billions of comets

13
Famous Comets
  • Comet Hale-Bopp
  • Halleys Comet
  • Comet Kohoutek

14
A Comets Tail
15
Asteroids
  • An irregularly shaped rocky object in space (like
    a space potato)
  • May be the shattered remains of objects left over
    from the time when the planets were formed

16
How big are asteroids?
  • Larger than meteoroids
  • (In fact, the main difference between meteoroids
    and asteroids is their size.)
  • Size ranges from 10 feet across to bigger than a
    mountain

17
Asteroids
  • Approx. 150,000 asteroids in the Solar System
  • Most are in a band that orbit the sun between
    Mars and Jupiter (Asteroid Belt)
  • Why are there all of those asteroids between Mars
    and Jupiter and not another planet?

18
Near-Earth Asteroids (NEAs)
  • At least 1000 asteroids orbit outside of the
    Asteroid Belt these could be a danger to Earth
  • Asteroids that cross Earths orbit are called
    Near-Earth Asteroids or NEAs
  • NEA / Earth collision not likely
  • But if it did, the affect of the impact would
    depend on the size of the asteroid

19
Large Asteroid hits Earth 65 Million
Years Ago
  • Catastrophic Collision
  • Asteroid 6 to 12 miles in diameter
  • Near the Yucatan Peninsula in the Gulf of Mexico

20
Large Asteroid hits Earth 65 Million
Years Ago
  • Collision produced an explosion 100
    trillion tons of dynamite
  • Gouged out a crater about 60 miles in diameter
  • How would an event like this affect Earth?

21
What do Scientists Think Happened?
  • Forests were wiped clean for a distance of 300 to
    600 miles in all directions
  • 300 foot wave struck the coast of Texas
  • Powerful Earthquakes
  • Landslides destroyed long stretches of coastline

22
What do Scientists Think Happened
  • Explosion threw huge amounts of debris into the
    air, covering large parts of North America
  • Poisonous gases and dust soared high into the
    atmosphere, spread over most of the Earth, and
    then fell back onto the Earths surface

23
What do Scientists Think Happened
  • Sunlight was blocked from reaching the Earths
    surface for many months
  • Temperatures plummeted to the freezing point in
    normally warm areas
  • Not enough sunlight for photosynthesis
  • Plants died . . . Animals died
  • Many animals became extinct (including many types
    of dinosaurs)

24
The Rise and Fall of Life on Earth
  • See the dip around 65 Million years ago?
  • This represents the extinction of about 75 of
    all the species alive at that time.

25
Is the Earth in danger of a large asteroid impact?
  • Not that we know of!
  • None of the asteroids or comets discovered so far
    is on a collision course with Earth.
  • However, we can't speak for those that are not
    yet discovered. In principle, one of those could
    hit any time, but statistically the chances are
    very small.

26
Torino Scale
  • A system used to rate the hazard level of an
    object moving toward Earth

27
Review
  • Q What is the difference between a meteoroid,
    meteororite, and a meteor?
  • Meteoroid while in space a meteorite is called
    a meteoroid
  • Meteorite a small rock or rocky grain that
    strikes Earths surface
  • Meteor Shooting Star

28
Review
  • Q What is the difference between an asteroid and
    a meteoroid?
  • The main difference is the size of the object.
  • Q Which is larger, asteroid or meteoroid?
  • Asteroids are larger than meteoroids.

29
Review
  • Q Why is it important to study smaller bodies in
    our Solar System such as comets or asteroids?
  • They help us learn about the history of our Solar
    System.

30
Review
  • Q Why do planets and moons with atmospheres have
    less impact craters than those without
    atmospheres?
  • The atmosphere slows and burns smaller objects
    like meteorites, thus many do not reach the
    surface to create an impact.

31
Review
  • Bright streaks of light that result when rocky
    bodies burn up in the atmosphere are called
    ___________.
  • Frozen bodies made of ice, rock, and dust,
    sometimes called dirty snowballs are called
    _____________.
  • Small, rocky bodies that revolve around the sun
    are called ______________.

32
Review
  • Bright streaks of light that result when rocky
    bodies burn up in the atmosphere are called
    meteors.
  • Frozen bodies made of ice, rock, and dust,
    sometimes called dirty snowballs are called
    comets.
  • Small, rocky bodies that revolve around the sun
    are called asteroids.

33
Review
  • Q Discus what could happen if the Earth
    experienced another large asteroid impact. How
    would it affect life on Earth?
  • Forests flattened for many miles
  • If asteroid landed in water, it would cause giant
    waves and landslides
  • Powerful Earthquakes

34
The devastation continues
  • Poisonous gases and dust fills the atmosphere,
    blocks out the sun
  • Temperatures drop drastically
  • No photosynthesis plants die animals die
  • Some animals become extinct

35
Review
  • Q Where is the Asteroid Belt?
  • Asteroid Belt is between Mars and Jupiter
  • Q What is the Torino Scale?
  • A system used to rate the hazard level of an
    object moving toward Earth
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