Download major properties of the solar system

ORIGIN OF THE SOLAR
SYSTEM
Chapter 12
MAJOR PROPERTIES OF
THE SOLAR SYSTEM
Each planet is isolated about twice as far from the Sun
as its inward neighbour.
 The orbit of each planet around the Sun is
approximately circular.
 The planetary orbits lie nearly in the same plane.
 The direction of revolution of the planets around the
Sun is the same as the Sun’s rotation.
 Most planets spin in the same direction except (V, U?
and P).
 Most moons revolve in the same direction as the
planets rotate.
 All of the above facts suggest a single formation event.

MAJOR PROPERTIES OF
THE SOLAR SYSTEM
 All
of the above
facts suggest a
single formation
event for the solar
system.
MAJOR PROPERTIES OF
THE SOLAR SYSTEM
 Chemical
The terrestrial planets
are depleted in light
elements such as H and
He.
Lighter elements were
not able to condense
(form solids) near the
Sun. These elements
escaped from the inner
regions of the Solar
System.
MAJOR PROPERTIES OF
THE SOLAR SYSTEM
Ages
Meteorites
are 4.5 billion years old.
MAJOR PROPERTIES OF
THE SOLAR SYSTEM
Ages
Parts
of the Moon are also 4.5 billion years old.
MAJOR PROPERTIES OF
THE SOLAR SYSTEM
Ages
Earth
is at least 3.8 billion years old.
FORMATION of the SOLAR
SYSTEM
 The Solar System
formed about 4.5
billion years ago
from the solar
nebula.
 New stars are
currently forming in
the Orion Nebula.
Orion Nebula
FORMATION of the SOLAR
SYSTEM
 The Eagle Nebula is also a region of current star
formation.
Eagle Nebula
FORMATION of the SOLAR
SYSTEM
 Gravity
pulls gas and dust to the centre of the nebula.
 Material spins faster as nebula shrinks.
 Easier
for material to fall into the poles than equator.
A disk is formed with most of the material collecting
in the central region.
The formation of a star
FORMATION of the SOLAR
SYSTEM
 Disks
are observed
around many young
stars.
 When
the supply of
dust and gas is
depleted, the
collapse of the
nebula ceases and
the nebula then
begins to cool.
Protoplanetary Disks in the Orion Nebula
FORMATION of the SOLAR
SYSTEM
 As
the nebula
cools, the gas
forms heavier
compounds.
 Water
is formed
far from the
centre. Its
presence on
Earth is
unexpected.
FORMATION of the SOLAR
SYSTEM
 Grains
aggregate together to form planetesimals
(1 - 10 km, some still seen as asteroids and
comets)
Asteroid Ida
Comet Hale-Bopp
FORMATION of the SOLAR
SYSTEM
 In
the inner Solar
System, planetesimals
accreted to form the
terrestrial planets.
 Era
of heavy
bombardment by
planetesimals melted
planets and caused
differentiation.
FORMATION of the SOLAR
SYSTEM
Primordial Earth glowed from impact generated heat.
FORMATION of the SOLAR
SYSTEM
 In
the outer Solar System, lots of gas was available.
Protopanetary cores accreted huge amounts of gas.
Protoplanetary
Cores
FORMATION of the SOLAR
SYSTEM
 The
collapse of the solar nebula and the formation of
the planets occurred in a few million years.
FORMATION of the SOLAR
SYSTEM
 The
collapse of the solar nebula and the formation of
the planets occurred in a few million years.
 Lots of planetesimals left in the inner solar system to
cause havoc.
Mercury
Moon
FORMATION of the SOLAR
SYSTEM
FORMATION of the SOLAR
SYSTEM
 One
or more large
planetesimals collided
with Venus and
reversed its spin
direction.
Venus
FORMATION of the SOLAR
SYSTEM
 One
or more planetesimals collided with Earth and
pulled out enough material to form the Moon.
FORMATION of the SOLAR
SYSTEM
 Initially,
the Earth had no
water. Icy comets hitting
Earth brought water and
organic compounds
from the outer region.
Comet West
SHOEMAKER-LEVI COMET
FORMATION of the SOLAR
SYSTEM
 Comets
continue to impact the planets.
Comet Shoemaker-Levi Impact Sites on Jupiter