Download A Census of the Solar System

A Census of the Solar System
1 star and 8 major planets
Mercury
Venus
terrestrial
giant
Earth
(1)
Mars
(2)
Jupiter
(39)
Saturn
(18)
Uranus
(23)
Neptune
(8)
Planetary comparisons
The Gas Giants
Jupiter -- 1/1000 Msun , 300 Mearth
1/10 Rsun , 11 Rearth
Terrestrial Objects
7 largest moons
Other members
Dwarf Planets – Pluto and the Trans-Neptunian
or Kuiper Belt Objects
Highly elliptical orbit inclined 170 to ecliptic
Brings it inside Neptune’s orbit, 1979 –
1999, Pluto was closer than Neptune
Asteroids, Meteors and Comets
Fundamental Properties of the solar System
1. Planets and their satellites all lie in the same plane - the ecliptic – to within a few degrees
2. Sun’s rotational equator aligned with ecliptic
3. Planetary orbits are nearly circular ellipses
4. Planets all revolve in same W -> E direction
5. Sun and planets all rotate on axes in same W –E direction (except Venus and Uranus)
6. Distance between planets have a regular spacing (Bode’s Law)
7. Planet – satellite systems resemble solar systems
8. comets define a large almost spherical cloud surrounding the solar system – Oort Cloud
9. Planet compositions differ and there is a gradient with distance from the Sun
10. All mass is in the Sun (99.9%) but most of the angular momentum is in the planets
Formation of Solar System
The Condensation Sequence of the
elements, minerals and molecules
The Heavy Bombardment
The Search for ExoSolar Planets
Astrometric Detection Method
Doppler Detection Method
Transit Detection Method
The first two methods are based on the fact that a planet orbiting a star will
cause the star to "wobble" in space.
The first method detects the component of this wobble that is horizontal to
our line of site, and is based simply on observing the position of the star
over time.
***The second method detects the component of the wobble
that is radial to us, (i.e. directly towards or away from us), and
is based on the Doppler shift in the star's light as the star
moves towards or away from us.
*** The third method is based on detecting the small drop in apparent
luminosity of a star as a planet transits in front of it, between the star
and the Earth.
ExtraSolar System Planets
Multiple systems
As of Sept, 2015 -- 1892 planets confirmed (JPL) + 5596 candidates
The Kepler Mission
Designed to constantly survey the same region of sky 105 sg deg
1.4 meter diameter mirror with a 0.95m photometer.
Uses the transit method and survey thousands of stars repeatedly at
least 3 – 4 times to determine period and orbit of transiting planet.
Results from Kepler satellite:
Press release Feb 2, 2011
A NASA telescope taking a nose count of planets in one small
neighborhood of the Milky Way registered more than 1,200 candidates,
including 58 residing in life-friendly orbits around their parent stars.
The census, collected by NASA's Kepler Space Telescope after just four
months of work, shows that small planets like Earth are much more
prevalent than Jupiter-sized worlds and that multiple-planet systems are
common (about 200).
As of Sept 2016 -- 2330 confirmed , + 4696 candidates
Of these, 21 are in less than twice Earth size and in the habitable zone,
http://kepler.nasa.gov/Mission/discoveries/
11 new systems with 26 planets
Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sunlike Star Dec 5 , 2011
Probably about mass of Neptune ~ 35M earths
Exo planet types
First Earth-sized planet in the habitable zone of another star, April 2014
Finding Habitable Worlds
Adaptive Optics – Interferometry – The Large Binocular Telescope
Figure'2:'LEECH'observations'of'HR'8799'(left)'and'Kappa'And'(right).''These'are'the'
most'sensitive'observations'taken'of'each'system.''No'planet'is'visible'interior'to'the'
known'planets.'
Characterizing%
the%
Atmospheres%
of%
Known%
Exoplanets:%
ESO Discovers Earth-Size Planet in Habitable
Zone of Nearest Star
The new planet circles Proxima Centauri, the smallest
member of a triple star system known to science fiction
fans everywhere as Alpha Centauri. Just over 4 lightyears away, Proxima is the closest star to Earth, besides
our own sun.
They determined that the new planet, dubbed Proxima b, is at
least 1.3 times the mass of Earth. It orbits its star far more closely
than Mercury orbits our sun, taking only 11 days to complete a
single orbit -- a "year" on Proxima b.
Web sites -- http://planetquest.jpl.nasa.gov/
exoplanet.eu
exoplanets.org (Caltech)
Kepler mission -- http://www.kepler.arc.nasa.gov/