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See these videos

http://www.youtube.com/watch?v=Uhy1fucSRQI

http://www.nasa.gov/topics/solarsystem/features/aste
roidflyby.html

 http://www.nasa.gov/mission_pages/sdo/news/sdo-
 year3.html

http://www.nasa.gov/centers/ames/news/releases/2012/12
ASA's Mars rover Curiosity
Formation OF THE SOLAR SYSTEM

                      Gas: 72 % Hydrogen
The stars - the
                      27 % Helium and
sun is a star-        1% other elements.
form inside           H is in the form of
large system of       molecules instead of atoms.
GAS and               Molecular clouds (MC).
DUST
                  Dust: tiny solid particles of
called            silicates and metals, formed
“molecular        in the atmospheres of dying
clouds”           stars.
                  1% of the mass of the MCs is
                  dust.
The Orion Nebula in
                      dust grains:
the visible
                      - seeds where
                      atoms
                      agglomerate, to
                      form planets
                      - absorb heat from
                      stars preventing
                      MCs from boiling
                      off
- On average low
Molecular clouds:
dust and gas          temp, 50 K
                    - Near stars it is
                      hot and glows
                    - MCs contain
                      CO that emits
                      radio radiation
                      allowing us to
                      map them
Visible                       IR




The sun formed when a molecular cloud core collapsed under its
gravitational pull.
Radio map of
Orion
constellation
Molecular             Solar Nebula
                Cloud
The sun and
the planets
formed after
a molecular                           proto-planets
cloud
collapsed

A parenthesis
to explain “
Conservation
of angular                  planets
momentum”
Conservation of Angular Momentum (L).
L= m(mass) ω(angular velocity) r2 (square of radius)

L= m ω r2 . Or L∝ω r2
Essentially this law tells that that the angular momentum of
an isolated system remains constant.

                                     To spin faster a skater
                                     brings her arms in
                                     reducing her radius of
                                     rotation.
                                     To slow down she
                                     opens up her arms
                                     increasing her radius
                                     of rotation.
        (r1)2 ω1   =   (r2)2 ω2
Example of conservation of angular momentum




   (r1)2 ω1           =          (r2)2 ω2
http://www.youtube.com/watch
v=AQLtcEAG9v0
Formation of a Solar Nebula.

             The original MC is cold (10 to 50 K)
             and has a small amount of rotation,
              The collapsed cloud is smaller and
              conservation of angular momentum
              tells that it rotates faster.
                      consequence

                Planets revolve in the same
                direction and almost in the same
                plane.
L∝ω r2
As the MC collapses
                        potential energy is
                        converted into heat,
                        so collapsed nebula
                        gets hotter, and
                        protosun is hot.

“solar Nebula” =
collapsed molecular cloud where sun forms
The Solar Nebula Develops a
 Temperature Gradient.



                 Hot                            Cold




                            2 000
                Temp. (K)


Gradient =
change of
                            1 000
temperature
with distance
                                    Distance (AU)
Most probable Steps for Planet Formation once
the solar nebula is formed.
  A- Condensation
                B- Accretion ( planetesimals)
 C- Formation of Proto-plantes.

      D- Density Differentiation (Only
      Terrestrial Planets).
  E-Formation of atmospheres

 Formation of terrestrial planet took
 ~ 100 million years.
Step 1.
Condensation:
As the solar nebula
cooled, atoms and
microscopic particles
condensed around
the dust particles, just as snow flakes
condenses out of the atmosphere.
   ( a hot system of gas and dust tends to
   dissipate)
The temperature gradient determines the elements
that condense in the different regions of the
nebula
    Cold
                   Hot                        frost
                                              line

 Frost line               2 000
              Temp. (K)




                          1 000



                                  Distance (AU)
Inside the frost line where the temperature
is high Fe, Ni, Al and silicates condense,
                                    and the terrestrial
                                    planets form.
   Cold
                    Hot


Frost line                 2 000
               Temp. (K)




                           1 000



                                   Distance (AU)
Beyond the frost line, where the temperature
    is lower ices, water, silicates and metals
    condense                         and the Jovian
                                     planets form.
   Cold
                    Hot


Frost line                 2 000
               Temp. (K)




                           1 000



                                   Distance (AU)
Step Two: Accretion and Formation of
 Planetesimals.
When condensation ends accretion begins.
Accretion: gradual
growth of small
particles by clumping
together (electrostatic
forces) and by soft
collisions ).
 The larger objects formed by accretion are the
 planetesimals.

Planetesimals = solid objects formed in the
proto-planetary disks of the solar nebula.
Conservation of angular tells us:
-planetesimals have different
orbits around the protosun
- move in almost the same
direction.
                   L∝ r ω 2



  Some collisions hppened
  -By soft collisions planetesimals coalesced into larger
  ones.
  -Head on collision shatters the planetesimals.

         Only a few large planetesimals survived.
Step        Terrestril Planetesimals Grow
Three.      to Form Proto Planets.
 Larger
 planetesimals
 attract smaller
 ones, and grow
 faster than
 smaller ones
 given rise to
                       http://www.nature.com/nature/journal/v473/n734
 proto-planets.        8/full/473460a.html?WT.ec_id=NATURE-
                       20110526

Terrestrial proto-planets are as big as the planets.
Important
Where the Jovian protoplanets       Where the terrestrial
formed gas and ices were abundant   protoplanets formed there
 and the protoplanets attracted     was no much matter
gasses and ices directly from the   available, so when they
nebula forming large atmosphers.    formed , they stopped
This process is known as            growing and they begun the
gravitational collapse.             process known as “density
                                    differentiation “




  Source NASA/JPL
Density Differentiation of terrestrial planets.
Density differentiation = separation of materials due
to density, mainly in the liquid state.
Before density
differentiation the
terrestrial
protoplanes were
homogeneous in
composition.
Initially the young terrestrial protoplanets melted due to
the :
a- heat of formation

b- heat released by
collision of captured
planetesimals and

c- heat released by
radioactive materials
in the interior of these
planets.
After differentiation                             Crust
the Terrestrial planets
essentially had three                Mantle
main regions:
the core of mainly
                                       Core
heavy elements, the
mantle a mixture of
heavy-light elements
and a crust of light
elements.


       Terrestrial planets formed [~ 100 million years]
Graphic representation of the evolution of the Solar Nebula.




Condensation
                      Accretion and
                      planetesimals             Protoplanets
What type of particles condensed out of the
solar nebula near the sun.
a.ices
b.ices and silicates.
c.silicates and metals.
 c. silicates and metals
d.Water and gases.
The Kuiper belt,
and the Ort cloud
were populated
with ice
planetesimals that
formed out of the
nebula but never
made it into
planets.
  The rocky asteroids might be the remains of a
  planet that never formed.
Most planets formed in
their present orbits.




                          Neptune and Uranus is
                         believed to have formed
                         nearer Jupiter’s orbit.
                         Gravitational interaction
                         with Jupiter pushed them
                         outwardly.
http://cougar.jpl.nasa.gov/HR4796/anim.html
Atmospheres of Planets.

a- The atmospheres of
the Jovian were drawn
directly from the
nebula.(Gravitational
collapse.)
Jovian have primary
atmospheres and they
never evolved.
b- The gases in the atmospheres of terrestrial
planets were the result of:

     out- gassing:
     (volcanic
     eruption)


                     collision of comets with the
                     surface of the planets.
As comets collided with the
young terrestrial planets gases
and water were released.
Initially the atmospheres of the
terrestrial planets were hot.
Earth’s and Mars’ cooled down
and the water condensed: rain
happened.
 ( Maybe it did not rain much on
Mars!!!)

On Earth the rain removed the carbon dioxide
from the atmosphere.
Mercury lost its atmosphere because it is too hot and
because it has a low escape velocity.

Venus’ atmosphere never cooled down. So water did
not condensed, (no rain). Its atmosphere remains hot
and unchanged, primeval atmosphere.

 Earth is the only planet with running water and with
 a Secondary Atmosphere.

 There is evidence that long time ago, more than 4
 billions year, Mars had running water. Mars What went
 wrong there? Where is the water?
Planetary impacts:

                            When the terrestrial
                            planets were young
                            large impacts were
                            common, every 100
                            years or so.


The Barringer Meteor            Small impacts
Crater (Arizona),               of meteorites
formed ~ 20 to 40               are still
million years ago, by a         occurring .
meteorite of 90 meters
in diameter.
The HST imaged
the Shoemaker-
Levy comet as it
fell in Jupiter's
atmosphere.
Most traces of larger impacts, on Earth,
have been erased by the movement of the
plates and by erosion.




A giant impact 65 million years ago
might have produced the extinction of
the dinosaurs.
Tunguska, 1908




http://science.nasa.gov/science-news/science-at-nasa/2008/30jun_tunguska/
Moons
           Jovian Planets:
Most larger moons probably formed with their parent
planets, directly from the nebula.

The smaller moons were probably captured asteroids.

 The moons are rocky and some are larger than
 Mercury and have atmospheres.

 Terrestrial Planets:
 Mercury and Venus do not have moons.
 Mars’ two small moons are captured asteroids.
Chap 5 part 2 students
Origin of EARTH and MOON




 Earth–Moon system may have formed after a collision with a planetesimal
 (the size of Mars).
Solar nebula theory explains:
 a- the existence of:
 TERRESTRIAL, JOVIAN and DWARFS.
 b- common age of solar system
  c- Origin of space debris.
d- Craters Produced by debris falling on planets.
Solar nebula theory explains:
e- the existence of many moons around the
Jovians and a few or none around the Terrestrials.
f.- large tilt of rotation of Uranus and Pluto and
backward rotation of Venus due.
Lack of crust on Mercury. . ( It seem that
Mercury lost its crust when a large
planetesimal collided ith the planet)
g- disk shape of the solar system and common
direction of revolution of planets around sun .
(The planets orbit the sun in the same direction
that the sun rotates).
Clearing the Nebula
 The gas and dust left over after the solar system
 was formed was cleared by the solar wind and by
 the sun’s radiation pressure.
The planetesimals left over were :
 gravitationally attracted by the planets
                   or
ejected by close encounters with planets.




This populated the Kuiper and Oort cloud.
Planets Around Other Stars or Exoplanets.

The solar nebula theory tells us that planets
around other stars are to be expected.

A total of 777 exoplanets (in 624 planetary
systems and 101 multiple planetary systems)
have been identified as of July 5, 2012

 The vast majority were detected through various
 indirect methods rather than actual imaging.
Stars are a billion
 …than the planet     times brighter…
                      V
                        VVVisual detection
                          is difficult.

…hidden
in the glare.
                            From
                            http://planetquest.jpl.nas
                            a.gov/gallery/frequentIma
                            ges.cfm
NASA Kepler Mission is a
              telescope whose aim is to to
              look for Earth-like planets.


 NASA's Kepler space
 telescope, was designed
 to find Earth-size
 planets in the habitable
 zone of sun-like stars.



Kepler detects planets indirectly, using the "transit"
method.
Analyzing the depth of the dip in brightness of the light
curve when a plant transits its “stars” astronomers can
find the radius of the orbit of a planet.
Image Credit: NASA Ames

http://kepler.nasa.gov/Mission/discoveries/kepler14b/
The Transit Method




            http://eo.ucar.edu/staff/dward/sao/exoplanets/methods.htm
Kepler MissionFebruary 02, 2012




             P = 28 days 25 Earth masses


New super-Earth detected within the habitable zone
of a nearby star.
http://planetquest.jpl.nasa.gov
Anbother method of detection of planets.

                                     Invisible
                                     planet.



The gravitational attraction of the invisible planet
causes the star to wobble.
As the invisible planet orbits the star its speed of
rotation constantly changes. The changes are
detected as a Doppler shift. Most of the exoplanets

                              have been detected in
                                   this way




    .
A planet around 51 Pegasi, 48 ly away,
was the first planet discovered using
this technique.


Beyond our own solar system, the planets
found so far tend to be large Jovians with
orbits more like terrestrial planets.

 Until we can observe terrestrial planets, we
 will not be able to draw conclusions about
 the uniqueness of our own system. Kepler
 telescope is looking out for Earth like
 planets.
Summary of the Nebula
 Theory.
I- A slowly rotating cloud of gas and
dust, 2 ly across, collapses under its own
gravity.

II- Proto- sun forms at center of the
collapsed cloud or SOLAR NEBULA.
III- rotation flattens cloud, forming disk
around proto-sun
IV - planets gradually formed in rotating
disk
V -As luminosity of sun increases, gas
and dust is eventually blown away
Which of the following is (are) are explained by
the solar nebula theory?
a- the orbits of the planets are nearly circular, and
almost in the same plane.
b- the planets orbit the Sun is the same direction that
the sun rotates.
c- the terrestrial planets have higher density and
lower mass.
d- comets do not necessarily orbit in the plane of the
solar system.
e. all of the above
 e. all of the above
Image ____ shows the planet Uranus.




a           b             c           d
Select the correct sequence of the figures in order of
occurrence. (Planet formation)
a- a b c d e                   b- d a b a c
c- e d c a b                  d- c e b a d
 a
                              d


b
                                  e


c
The image represents
a- FAU’s football stadium   b- the Daytona car race
track
c- the Oort cloud                 d- the Kuiper belt
What are the name of the objects inside the
closed dotted lines?

              Mars




                     Sun



                           Jupiter

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Chap 5 part 2 students

  • 1. See these videos http://www.youtube.com/watch?v=Uhy1fucSRQI http://www.nasa.gov/topics/solarsystem/features/aste roidflyby.html http://www.nasa.gov/mission_pages/sdo/news/sdo- year3.html http://www.nasa.gov/centers/ames/news/releases/2012/12
  • 2. ASA's Mars rover Curiosity
  • 3. Formation OF THE SOLAR SYSTEM Gas: 72 % Hydrogen The stars - the 27 % Helium and sun is a star- 1% other elements. form inside H is in the form of large system of molecules instead of atoms. GAS and Molecular clouds (MC). DUST Dust: tiny solid particles of called silicates and metals, formed “molecular in the atmospheres of dying clouds” stars. 1% of the mass of the MCs is dust.
  • 4. The Orion Nebula in dust grains: the visible - seeds where atoms agglomerate, to form planets - absorb heat from stars preventing MCs from boiling off
  • 5. - On average low Molecular clouds: dust and gas temp, 50 K - Near stars it is hot and glows - MCs contain CO that emits radio radiation allowing us to map them
  • 6. Visible IR The sun formed when a molecular cloud core collapsed under its gravitational pull.
  • 8. Molecular Solar Nebula Cloud The sun and the planets formed after a molecular proto-planets cloud collapsed A parenthesis to explain “ Conservation of angular planets momentum”
  • 9. Conservation of Angular Momentum (L). L= m(mass) ω(angular velocity) r2 (square of radius) L= m ω r2 . Or L∝ω r2 Essentially this law tells that that the angular momentum of an isolated system remains constant. To spin faster a skater brings her arms in reducing her radius of rotation. To slow down she opens up her arms increasing her radius of rotation. (r1)2 ω1 = (r2)2 ω2
  • 10. Example of conservation of angular momentum (r1)2 ω1 = (r2)2 ω2 http://www.youtube.com/watch v=AQLtcEAG9v0
  • 11. Formation of a Solar Nebula. The original MC is cold (10 to 50 K) and has a small amount of rotation, The collapsed cloud is smaller and conservation of angular momentum tells that it rotates faster. consequence Planets revolve in the same direction and almost in the same plane. L∝ω r2
  • 12. As the MC collapses potential energy is converted into heat, so collapsed nebula gets hotter, and protosun is hot. “solar Nebula” = collapsed molecular cloud where sun forms
  • 13. The Solar Nebula Develops a Temperature Gradient. Hot Cold 2 000 Temp. (K) Gradient = change of 1 000 temperature with distance Distance (AU)
  • 14. Most probable Steps for Planet Formation once the solar nebula is formed. A- Condensation B- Accretion ( planetesimals) C- Formation of Proto-plantes. D- Density Differentiation (Only Terrestrial Planets). E-Formation of atmospheres Formation of terrestrial planet took ~ 100 million years.
  • 15. Step 1. Condensation: As the solar nebula cooled, atoms and microscopic particles condensed around the dust particles, just as snow flakes condenses out of the atmosphere. ( a hot system of gas and dust tends to dissipate)
  • 16. The temperature gradient determines the elements that condense in the different regions of the nebula Cold Hot frost line Frost line 2 000 Temp. (K) 1 000 Distance (AU)
  • 17. Inside the frost line where the temperature is high Fe, Ni, Al and silicates condense, and the terrestrial planets form. Cold Hot Frost line 2 000 Temp. (K) 1 000 Distance (AU)
  • 18. Beyond the frost line, where the temperature is lower ices, water, silicates and metals condense and the Jovian planets form. Cold Hot Frost line 2 000 Temp. (K) 1 000 Distance (AU)
  • 19. Step Two: Accretion and Formation of Planetesimals. When condensation ends accretion begins. Accretion: gradual growth of small particles by clumping together (electrostatic forces) and by soft collisions ). The larger objects formed by accretion are the planetesimals. Planetesimals = solid objects formed in the proto-planetary disks of the solar nebula.
  • 20. Conservation of angular tells us: -planetesimals have different orbits around the protosun - move in almost the same direction. L∝ r ω 2 Some collisions hppened -By soft collisions planetesimals coalesced into larger ones. -Head on collision shatters the planetesimals. Only a few large planetesimals survived.
  • 21. Step Terrestril Planetesimals Grow Three. to Form Proto Planets. Larger planetesimals attract smaller ones, and grow faster than smaller ones given rise to http://www.nature.com/nature/journal/v473/n734 proto-planets. 8/full/473460a.html?WT.ec_id=NATURE- 20110526 Terrestrial proto-planets are as big as the planets.
  • 22. Important Where the Jovian protoplanets Where the terrestrial formed gas and ices were abundant protoplanets formed there and the protoplanets attracted was no much matter gasses and ices directly from the available, so when they nebula forming large atmosphers. formed , they stopped This process is known as growing and they begun the gravitational collapse. process known as “density differentiation “ Source NASA/JPL
  • 23. Density Differentiation of terrestrial planets. Density differentiation = separation of materials due to density, mainly in the liquid state. Before density differentiation the terrestrial protoplanes were homogeneous in composition.
  • 24. Initially the young terrestrial protoplanets melted due to the : a- heat of formation b- heat released by collision of captured planetesimals and c- heat released by radioactive materials in the interior of these planets.
  • 25. After differentiation Crust the Terrestrial planets essentially had three Mantle main regions: the core of mainly Core heavy elements, the mantle a mixture of heavy-light elements and a crust of light elements. Terrestrial planets formed [~ 100 million years]
  • 26. Graphic representation of the evolution of the Solar Nebula. Condensation Accretion and planetesimals Protoplanets
  • 27. What type of particles condensed out of the solar nebula near the sun. a.ices b.ices and silicates. c.silicates and metals. c. silicates and metals d.Water and gases.
  • 28. The Kuiper belt, and the Ort cloud were populated with ice planetesimals that formed out of the nebula but never made it into planets. The rocky asteroids might be the remains of a planet that never formed.
  • 29. Most planets formed in their present orbits. Neptune and Uranus is believed to have formed nearer Jupiter’s orbit. Gravitational interaction with Jupiter pushed them outwardly.
  • 31. Atmospheres of Planets. a- The atmospheres of the Jovian were drawn directly from the nebula.(Gravitational collapse.) Jovian have primary atmospheres and they never evolved.
  • 32. b- The gases in the atmospheres of terrestrial planets were the result of: out- gassing: (volcanic eruption) collision of comets with the surface of the planets.
  • 33. As comets collided with the young terrestrial planets gases and water were released. Initially the atmospheres of the terrestrial planets were hot. Earth’s and Mars’ cooled down and the water condensed: rain happened. ( Maybe it did not rain much on Mars!!!) On Earth the rain removed the carbon dioxide from the atmosphere.
  • 34. Mercury lost its atmosphere because it is too hot and because it has a low escape velocity. Venus’ atmosphere never cooled down. So water did not condensed, (no rain). Its atmosphere remains hot and unchanged, primeval atmosphere. Earth is the only planet with running water and with a Secondary Atmosphere. There is evidence that long time ago, more than 4 billions year, Mars had running water. Mars What went wrong there? Where is the water?
  • 35. Planetary impacts: When the terrestrial planets were young large impacts were common, every 100 years or so. The Barringer Meteor Small impacts Crater (Arizona), of meteorites formed ~ 20 to 40 are still million years ago, by a occurring . meteorite of 90 meters in diameter.
  • 36. The HST imaged the Shoemaker- Levy comet as it fell in Jupiter's atmosphere.
  • 37. Most traces of larger impacts, on Earth, have been erased by the movement of the plates and by erosion. A giant impact 65 million years ago might have produced the extinction of the dinosaurs.
  • 39. Moons Jovian Planets: Most larger moons probably formed with their parent planets, directly from the nebula. The smaller moons were probably captured asteroids. The moons are rocky and some are larger than Mercury and have atmospheres. Terrestrial Planets: Mercury and Venus do not have moons. Mars’ two small moons are captured asteroids.
  • 41. Origin of EARTH and MOON Earth–Moon system may have formed after a collision with a planetesimal (the size of Mars).
  • 42. Solar nebula theory explains: a- the existence of: TERRESTRIAL, JOVIAN and DWARFS. b- common age of solar system c- Origin of space debris. d- Craters Produced by debris falling on planets.
  • 43. Solar nebula theory explains: e- the existence of many moons around the Jovians and a few or none around the Terrestrials. f.- large tilt of rotation of Uranus and Pluto and backward rotation of Venus due. Lack of crust on Mercury. . ( It seem that Mercury lost its crust when a large planetesimal collided ith the planet) g- disk shape of the solar system and common direction of revolution of planets around sun . (The planets orbit the sun in the same direction that the sun rotates).
  • 44. Clearing the Nebula The gas and dust left over after the solar system was formed was cleared by the solar wind and by the sun’s radiation pressure. The planetesimals left over were : gravitationally attracted by the planets or ejected by close encounters with planets. This populated the Kuiper and Oort cloud.
  • 45. Planets Around Other Stars or Exoplanets. The solar nebula theory tells us that planets around other stars are to be expected. A total of 777 exoplanets (in 624 planetary systems and 101 multiple planetary systems) have been identified as of July 5, 2012 The vast majority were detected through various indirect methods rather than actual imaging.
  • 46. Stars are a billion …than the planet times brighter… V VVVisual detection is difficult. …hidden in the glare. From http://planetquest.jpl.nas a.gov/gallery/frequentIma ges.cfm
  • 47. NASA Kepler Mission is a telescope whose aim is to to look for Earth-like planets. NASA's Kepler space telescope, was designed to find Earth-size planets in the habitable zone of sun-like stars. Kepler detects planets indirectly, using the "transit" method.
  • 48. Analyzing the depth of the dip in brightness of the light curve when a plant transits its “stars” astronomers can find the radius of the orbit of a planet. Image Credit: NASA Ames http://kepler.nasa.gov/Mission/discoveries/kepler14b/
  • 49. The Transit Method http://eo.ucar.edu/staff/dward/sao/exoplanets/methods.htm
  • 50. Kepler MissionFebruary 02, 2012 P = 28 days 25 Earth masses New super-Earth detected within the habitable zone of a nearby star. http://planetquest.jpl.nasa.gov
  • 51. Anbother method of detection of planets. Invisible planet. The gravitational attraction of the invisible planet causes the star to wobble.
  • 52. As the invisible planet orbits the star its speed of rotation constantly changes. The changes are detected as a Doppler shift. Most of the exoplanets have been detected in this way .
  • 53. A planet around 51 Pegasi, 48 ly away, was the first planet discovered using this technique. Beyond our own solar system, the planets found so far tend to be large Jovians with orbits more like terrestrial planets. Until we can observe terrestrial planets, we will not be able to draw conclusions about the uniqueness of our own system. Kepler telescope is looking out for Earth like planets.
  • 54. Summary of the Nebula Theory. I- A slowly rotating cloud of gas and dust, 2 ly across, collapses under its own gravity. II- Proto- sun forms at center of the collapsed cloud or SOLAR NEBULA. III- rotation flattens cloud, forming disk around proto-sun IV - planets gradually formed in rotating disk V -As luminosity of sun increases, gas and dust is eventually blown away
  • 55. Which of the following is (are) are explained by the solar nebula theory? a- the orbits of the planets are nearly circular, and almost in the same plane. b- the planets orbit the Sun is the same direction that the sun rotates. c- the terrestrial planets have higher density and lower mass. d- comets do not necessarily orbit in the plane of the solar system. e. all of the above e. all of the above
  • 56. Image ____ shows the planet Uranus. a b c d
  • 57. Select the correct sequence of the figures in order of occurrence. (Planet formation) a- a b c d e b- d a b a c c- e d c a b d- c e b a d a d b e c
  • 58. The image represents a- FAU’s football stadium b- the Daytona car race track c- the Oort cloud d- the Kuiper belt
  • 59. What are the name of the objects inside the closed dotted lines? Mars Sun Jupiter