The chapter summarizes the current understanding of the solar system. It describes the major components, including the Sun, 8 planets, asteroids, comets, and over 100 moons. It also differentiates between terrestrial and Jovian planets. Additionally, it discusses early theories about how the solar system formed via a contracting nebula and dust condensation.
2. Units of Chapter 6
An Inventory of the Solar System
Planetary Properties
Computing Planetary Properties
The Overall Layout of the Solar System
Terrestrial and Jovian Planets
Interplanetary Debris
3. Units of Chapter 6, cont.
Spacecraft Exploration of the Solar System
Gravitational Slingshots
g
How Did the Solar System Form?
The C
Th Concept of Angular Momentum
t fA l M t
4. 6.1 An Inventory of the Solar System
Early
Earl astronomers kne Moon, stars, Merc r
knew Moon stars Mercury,
Venus, Mars, Jupiter, Saturn, comets, and
meteors
Now known: Solar system has 135 moons, one
star,
star nine planets (added Uranus Neptune and
Uranus, Neptune,
Pluto), asteroids, comets, and meteoroids
6. 6.2 Planetary Properties
Distance from Sun known by Keplers laws
Orbital period can be observed
Radius known from angular size
Masses from Newtons laws
Rotation period from observations
Density can be calculated knowing radius and
mass
7. 6.4 Terrestrial and Jovian Planets
Terrestrial planets:
Mercury, Venus, Earth,
Mars
Jovian planets:
Jupiter, Saturn, Uranus,
Neptune
Pluto is neither
8. 6.4 Terrestrial and Jovian Planets
Differences between the terrestrial planets:
Atmospheres and surface conditions are very
dissimilar
di i il
Only Earth has oxygen in atmosphere and liquid
water on surface
Earth and Mars rotate at about the same rate; Venus
and Mercury are much slower and Venus rotates in the
slower,
opposite direction
Earth and Mars have moons; Mercury and Venus
dont
Earth and Mercury have magnetic fields; Venus and
y g ;
Mars dont
10. 6.7 How Did the Solar System Form?
Nebular
N b l contraction:
i
Cloud of gas and dust contracts due to gravity;
conservation of angular momentum means it spins
faster and faster as it contracts
11. 6.7 How Did the Solar System Form?
Condensation theory:
y
Interstellar dust grains
help cool cloud, and act as
condensation nuclei
12. Summary of Chapter 6
Solar system consists of Sun and everything
orbiting it
Asteroids are rocky, and most orbit between
orbits of Mars and Jupiter
p
Comets are icy, and are believed to have
formed early in the solar system s life
systems
Major planets orbit Sun in same sense, and all
but Venus rotate in that sense as well
Planetary orbits lie almost in the same plane
13. Summary of Chapter 6, cont.
Four inner planets terrestrial planets are
rocky, small, and dense
y
Four outer planets jovian planets (omitting
Pluto) are gaseous and large
Nebular theory of solar system formation:
cloud of gas and dust gradually collapsed under
its own gravity, spinning faster as it shrank
C d
Condensation theory says dust grains acted as
ti th d t i t d
condensation nuclei, beginning formation of
larger objects