Asteroids:

1
Asteroids

• Are rocky and smalltypically the size of a grain
  of rice or a marble
• Are rocky, with a wide range of sizes, up to
  hundreds of miles in diameter
• Have only thin atmospheres
• Are made mostly of metals
• Are mostly found in the inner solar system

2
Asteroids

• Are rocky and smalltypically the size of a grain
  of rice or a marble
• Are rocky, with a wide range of sizes, up to
  hundreds of miles in diameter
• Have only thin atmospheres
• Are made mostly of metals
• Are mostly found in the inner solar system

3
If you keep pushing a person on a swing with
little pushes, at just the right frequency, they
will swing very high. This is an example of

• Newtons second law
• Newtons first law
• Energy conservation
• Resonance
• Conservation of angular momentum

4
If you keep pushing a person on a swing with
little pushes, at just the right frequency, they
will swing very high. This is an example of

• Newtons second law
• Newtons first law
• Energy conservation
• Resonance
• Conservation of angular momentum

5
Orbits of asteroids in the asteroid belt

• Often intersect planets
• Are mostly between Mars and Jupiter
• Are grouped into patterns by resonances with
  Jupiter
• Are mostly inside the frost line
• All except 1

6
Orbits of asteroids in the asteroid belt

• Often intersect planets
• Are mostly between Mars and Jupiter
• Are grouped into patterns by resonances with
  Jupiter
• Are mostly inside the frost line
• All except 1

7
What is the best way to find the densities of
asteroids?

• Since they are made of rock, they must be similar
  to earths density.
• Find what they are made of. Metal is heavier than
  rock, for instance.
• Find an asteroid with a moon and use Keplers 3rd
  law
• None of the above

8
What is the best way to find the densities of
asteroids?

• Since they are made of rock, they must be similar
  to earths density.
• Find what they are made of. Metal is heavier than
  rock, for instance.
• Find an asteroid with a moon and use Keplers 3rd
  law
• None of the above

9
Meteorites come from

• Starsthey are falling stars
• Destroyed planets
• Asteroids
• The Moon and Mars
• Volcanic ejecta

10
Meteorites come from

• Starsthey are falling stars
• Destroyed planets
• Asteroids
• The Moon and Mars
• Volcanic ejecta

11
A typical meteorite is

• About the size of a house, and makes a crater
  when it lands
• About the size of a pea or grain of rice and is
  invisible when it lands
• About the size of a pea or grain of rice. It
  makes a bright streak in the sky and burns up
• Made of ice

12
A typical meteorite is

• About the size of a house, and makes a crater
  when it lands
• About the size of a pea or grain of rice and is
  invisible when it lands
• About the size of a pea or grain of rice. It
  makes a bright streak in the sky and burns up
• Made of ice

13
A meteor

• Is a flash of light
• Made by a falling meteorite
• While rushing through the air in flight
• It usually is seen at night
• All of the above

14
A meteor

• Is a flash of light
• Made by a falling meteorite
• While rushing through the air in flight
• It usually is seen at night
• All of the above This answer was given on an
  exam by a student, who added, I hope to God this
  answers right!

15
Primitive meteorites

• Are approximately 4.6 billion years old
• Give us clues to what the early solar system was
  like
• Represent samples of shattered worlds
• 1 and 2
• 1, 2, and 3

16
Primitive meteorites

• Are approximately 4.6 billion years old
• Give us clues to what the early solar system was
  like
• Represent samples of shattered worlds
• 1 and 2
• 1, 2, and 3

17
Processed meteorites

• Are meteorites that have been altered in a lab
  for study
• Came from a parent body that was large enough to
  develop a core and mantle
• May be iron or rocky
• All of the above
• 2 and 3

18
Processed meteorites

• Are meteorites that have been altered in a lab
  for study
• Came from a parent body that was large enough to
  develop a core and mantle
• May be iron or rocky
• All of the above
• 2 and 3

19
Comets

• Formed from planetesimals in the inner part of
  the early solar system
• Formed from planetesimals in the outer part of
  the early solar system
• Orbit the Sun and return time after time, for
  billions of years
• Have a tail that follows them in their orbit
  around the Sun

20
Comets

• Formed from planetesimals in the inner part of
  the early solar system
• Formed from planetesimals in the outer part of
  the early solar system
• Orbit the Sun and return time after time, for
  billions of years
• Have a tail that follows them in their orbit
  around the Sun

21
The nucleus of a comet

• Is filled with rock
• Is like a dirty snowball
• Turns to gas when the comet nears the sun
• All of the above
• 2 and 3

22
The nucleus of a comet

• Is filled with rock
• Is like a dirty snowball
• Turns to gas when the comet nears the sun
• All of the above
• 2 and 3

23
If the Earth passed through the tail of a comet,
what would happen?

• People would die from the gasses such as methane
  and ammonia
• It depends on if it was the gas tail or the dust
  tail
• Earth might be knocked out of its orbit or its
  axis might get tilted
• Nothing. Halleys comet did this and nothing
  happened

24
If the Earth passed through the tail of a comet,
what would happen?

• People would die from the gasses such as methane
  and ammonia
• It depends on if it was the gas tail or the dust
  tail
• Earth might be knocked out of its orbit or its
  axis might get tilted
• Nothing. Halleys comet did this and nothing
  happened

25
Why is there a meteor shower every year on Aug.
10, 11, and 12?

• Meteorites only enter the solar system on certain
  dates
• Meteorites often have 1 year orbital periods
• Each year at that time Earth passes through the
  orbit of a comet and hits the debris it left
• None of the above

26
Why is there a meteor shower every year on Aug.
10, 11, and 12?

• Meteorites only enter the solar system on certain
  dates
• Meteorites often have 1 year orbital periods
• Each year at that time Earth passes through the
  orbit of a comet and hits the debris it left
• None of the above

27
What is plasma (in astronomy)?

• An element commonly found in space
• A constituent of blood
• An ionized or charged gas, made when atoms lose
  one or more electrons
• Another name for the solar wind

28
What is plasma (in astronomy)?

• An element commonly found in space
• A constituent of blood
• An ionized or charged gas, made when atoms lose
  one or more electrons
• Another name for the solar wind

29
Why do comet tails always point away from the Sun?

• They are left behind as the comet moves
• Newtons third law Comet goes one way, tail goes
  the other
• The solar wind blows on them
• They dont this is just a perspective effect of
  how we view them

30
Why do comet tails always point away from the Sun?

• They are left behind as the comet moves
• Newtons third law Comet goes one way, tail goes
  the other
• The solar wind blows on them
• They dont this is just a perspective effect of
  how we view them
• Noticing comet tail directions enabled
  astronomer Ludwig Biermann to predict the solar
  windyears before any spacecraft actually
  detected it!

31
Every time a comet gets near the Sun, some of its
material streams away in the tail. Shouldnt all
comets be gone?

• Yes
• No, not that much vaporizes
• Yes, but there are more comets stored in deep
  freeze beyond Pluto
• There probably used to be a lot more comets they
  are mostly all gone

32
Every time a comet gets near the Sun, some of its
material streams away in the tail. Shouldnt all
comets be gone?

• Yes
• No, not that much vaporizes
• Yes, but there are more comets stored in deep
  freeze beyond Pluto
• There probably used to be a lot more comets they
  are mostly all gone

33
What is the reservoir of cold comets beyond
Pluto called?

• The comet reservoir
• The extra-solar system source
• The Kuiper belt
• Interstellar space
• Planet X

34
What is the reservoir of cold comets beyond
Pluto called?

• The comet reservoir
• The extra-solar system source
• The Kuiper belt
• Interstellar space
• Planet X

35
What do you think Pluto is?

• A planet
• A Kuiper belt comet
• An escaped moon of Neptune
• Its too large to be a comet
• An asteroid

36
What do you think Pluto is?

• A planet
• A Kuiper belt comet
• An escaped moon of Neptune
• Its too large to be a comet
• An asteroid

37
Some comets come from far out in space and from
all different directions not in the plane of
the solar system.

• They probably come from other solar systems
  near other stars.
• They probably come from nebulae in interstellar
  space.
• We think theres a giant spherical cloud they
  come from the Oort cloud.
• The probably come from the Kuiper belt when a
  comet is flung out by Neptunes gravity

38
Some comets come from far out in space and from
all different directions not in the plane of
the solar system.

• They probably come from other solar systems
  near other stars.
• They probably come from nebulae in interstellar
  space.
• We think theres a giant spherical cloud they
  come from the Oort cloud.
• The probably come from the Kuiper belt when a
  comet is flung out by Neptunes gravity

39
How rare or common are impacts of asteroids and
comets into the Earth?

• Ones big enough to kill off all life on
  Earthmaybe once in 100 million years
• Smaller impacts, which would make mile-sized
  craters--every few thousand years
• As common as on the Moon, but erosion has warn
  away old craters
• Pretty common. Earth has hundreds of large
  cratersif you know where to look
• All of the above

40
How rare or common are impacts of asteroids and
comets into the Earth?

• Ones big enough to kill off all life on
  Earthmaybe once in 100 million years
• Smaller impacts, which would make mile-sized
  craters--every few thousand years
• As common as on the Moon, but erosion has warn
  away old craters
• Pretty common. Earth has hundreds of large
  cratersif you know where to look
• All of the above

41

• About how often is it estimated that an asteroid
  or comet impacts the Earth with sufficient energy
  to cause mass extinction?
• Once a millennium.
• Once every million years.
• Once every hundred million years.
• Once in an Earth lifetime.

42

• About how often is it estimated that an asteroid
  or comet impacts the Earth with sufficient energy
  to cause mass extinction?
• Once a millennium.
• Once every million years.
• Once every hundred million years.
• Once in an Earth lifetime.

43

• Surprising discovery? - A small asteroid that
  orbits within the asteroid belt has an active
  volcano.
• Plausible. Several small objects in the solar
  system have active volcanoes (e.g. Io).
• Plausible. Several asteroids are known to be
  composed of basaltic (lava) material.
• Implausible. Only planets, not moons or
  asteroids, have volcanoes.
• Implausible. Asteroids are too small to be
  geologically active now.

44

• Surprising discovery? - A small asteroid that
  orbits within the asteroid belt has an active
  volcano.
• Plausible. Several small objects in the solar
  system have active volcanoes (e.g. Io).
• Plausible. Several asteroids are known to be
  composed of basaltic (lava) material.
• Implausible. Only planets, not moons or
  asteroids, have volcanoes.
• Implausible. Asteroids are too small to be
  geologically active now.

45

• Surprising discovery? - A mission to Pluto finds
  that it has lakes of liquid water on its surface.
• Plausible. Other icy bodies at great distances
  from the Sun may also have liquid water.
• Plausible. Studies of Plutos surface show a
  long, narrow feature that has been suggested to
  be a lake.
• Implausible. Water would be frozen at Plutos
  temperature, and we know of no extra heat
  sources.
• Implausible. Pluto is mostly made of rock and
  metals, not water.

46

• Surprising discovery? - A mission to Pluto finds
  that it has lakes of liquid water on its surface.
• Plausible. Other icy bodies at great distances
  from the Sun may also have liquid water.
• Plausible. Studies of Plutos surface show a
  long, narrow feature that has been suggested to
  be a lake.
• Implausible. Water would be frozen at Plutos
  temperature, and we know of no extra heat
  sources.
• Implausible. Pluto is mostly made of rock and
  metals, not water.