Chapter 4 The Solar System Interplanetary Matter and the Birth of Planets - PowerPoint PPT Presentation

1 / 22
About This Presentation
Title:

Chapter 4 The Solar System Interplanetary Matter and the Birth of Planets

Description:

Chapter 4. The Solar System. Interplanetary Matter and the Birth of Planets. AST 1002 Introduction to Astronomy. Dr. Mike Reynolds. Our Solar System... Made up of: ... – PowerPoint PPT presentation

Number of Views:316
Avg rating:3.0/5.0
Slides: 23
Provided by: Mik7177
Category:

less

Transcript and Presenter's Notes

Title: Chapter 4 The Solar System Interplanetary Matter and the Birth of Planets


1
Chapter 4The Solar SystemInterplanetary Matter
and the Birth of Planets
  • AST 1002 Introduction to Astronomy
  • Dr. Mike Reynolds

2
Our Solar System
  • Made up of
  • One Central Star
  • Eight (or nine, or ten ) known Planets
  • Satellites orbiting the Planets
  • Miscellaneous debris Minor Bodies asteroids,
    meteoroids, comets, dust
  • Astronomers believe the Solar System is about 4.6
    billion years old
  • Why do we think it is that old?
  • Through the study of meteorites and dating of
    these objects

3
Solar System Formation
  • Sohow did the Solar System form and end up with
    all these different types of objects?
  • Currently the best theory is the Nebular Theory
  • The Solar System developed out of an interstellar
    cloud of dust and gas
  • Cloud of dust and gas also called a Nebula
  • This theory best accounts for the objects we
    currently find in the Solar System and the
    distribution of these objects

4
Nebular Theory Specifics
  • Started with a cloud of gas and dust
  • Most likely left over from a previous supernovae
  • Nebula started to collapse and condense this
    process continued
  • The Sun-to-be collected most of the mass in the
    nebulas center, forming a Protostar
  • Protostar No nuclear fusion at first
  • Probably next flattened into a disk called the
    Protoplanetary Disk
  • Planets eventually formed from / in this disk

5
Why is the Solar System Orderly?
  • With a beginning as a cloud of gas and dust, this
    cloud most likely was
  • Somewhat spherical
  • Had a low pressure and low density
  • Something started the nebula collapse
  • Once the collapse began, gravity would have
    caused the collapse to continue

6
Processes and Results
  • Three processes occurred with the nebular
    collapse
  • Temperatures continued to increase
  • The solar nebula spun faster and faster
  • The solar nebula disk flattened
  • The orderly motions of the Solar System today are
    a direct result of the Solar Systems beginnings
    in a spinning, flattened cloud of gas and dust

7
What Evidence Do We Have?
  • We see discs of gas and dust around other stars
  • Evidence of stars forming in clouds of gas and
    dust
  • Computer modeling
  • Other disk-forming evidence found throughout the
    Universe
  • Similar Situations and modeling, like spiral
    galaxies

8
Other Important Evidence
  • The types of objects found within the Solar
    System provide significant clues
  • Types of Planets and their distributions
  • Rocky or Terrestrial close to the Sun
  • Gas Giants or Jovian far from the Sun
  • Dwarf Icy far , far from the Sun
  • Comets and Asteroids
  • Meteorites recovered on Earth
  • Motions of most Solar System objects
  • Orbit and rotate in an organized fashion

9
But Alas! A Few Exceptions
  • Pluto,
  • Eris
  • Earth with a large moon
  • Uranus tilted on its side
  • Venus retrograde rotation

10
Other Solar Systems?
  • Yes! We have found evidence of Extra-Solar
    Planets
  • Look for a wiggle in the stars position via its
    spectrum (red/blue shifts)
  • Finds the planet indirectly
  • Dr. Geoff Marcy first to see this
  • Also look for a brightness drop transit
  • Gravitational lensing
  • BIG! Most of these are much bigger than Jupiter
  • Three planets have been found around the star
    Upsilon Andromeda
  • Over 160 Stellar Systems have been discovered to
    date!

11
Data courtesy Chabot Observatory Dr. Terry
Galloway et al.
12
A couple of Earth-Size Planets
  • HD 69830
  • Announced in January 2006
  • Appears to be five Earth Masses, Icy planet (more
    like Pluto/Eris than Earth)
  • Discovered by gravitational lensing
  • Artist's impression
  • Credit European
  • Space Organization

13
The 1st Really Earth-Like Extrasolar Planet
Discovered
Gliese 581c
14
What is Gliese 581?
  • A red dwarf star
  • Mass is 1/3 that of the Sun
  • Red dwarfs are at least 50 times fainter than the
    Sun and are the most common stars in our Galaxy
  • Located 20.40 light years from Earth
  • Among the 100 closest stars to us

15
The Gliese 581 System
  • Currently known to have three planets
  • Gliese 581b 16X as massive as Earth completes
    one orbit of Gliese 581 in 5.4 days
  • Appears to be Neptune-like
  • Gliese 581c rocky planet 1.5X Earths radius
  • Gliese 581d 8X as massive as Earth orbits
    Gliese 581 in 84 days

16
What About Gliese 581c
  • Gliese 581c is 14X closer to its star than the
    Earth is from the Sun
  • It is estimated that the mean temperature of
    Gliese 581c lies between 0o and 40o C
  • water would thus be liquid.
  • Its radius should be only 1.5 times the Earth's
    radius, and models predict that the planet should
    be either rocky - like our Earth - or covered
    with oceans.
  • Stéphane Udry
  • Member of the discovery team

17
Artists impression of Gliese 581 system Credit
ESO
18
What is Gliese 581c? A planet of Jabba the Hutts?
Well you would have to adjust Jabba for the 2X
Earth's gravity!
19
Liquid water is critical to life as we know it.
Because of its temperature and relative
proximity, this planet will most probably be a
very important target of the future space
missions dedicated to the search for
extra-terrestrial life. On the treasure map of
the Universe, one would be tempted to mark this
planet with an X.
  • Xavier Delfosse
  • Member of the discovery team from Grenoble
    University (France)

20
HD 69830 Gliese 581cA Comparison
21
Extrasolar Planets
  • Can tell us a lot about our Solar System
    formation
  • There are some significant issues at this point
  • Extrasolar planets are mostly much bigger than
    Jupiter
  • Extrasolar planets orbit much closer to their
    stars than our Gas Giants
  • Theory here is these Gas Giants migrated closer
    to their stars

22
(No Transcript)
Write a Comment
User Comments (0)
About PowerShow.com