Starry Monday at Otterbein

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Starry Monday at Otterbein
Welcome to

• Astronomy Lecture Series
• -every first Monday of the month-
• June 6, 2005
• Dr. Uwe Trittmann

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Todays Topics

• Saturn the ringed Planet
• The Night Sky in June

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Feedback!

• Please write down suggestions/your interests on
  the note pads provided
• If you would like to hear from us, please leave
  your email / address
• To learn more about astronomy and physics at
  Otterbein, please visit
• http//www.otterbein.edu/dept/PHYS/weitkamp.asp
  (Obs.)
• http//www.otterbein.edu/dept/PHYS/ (Physics
  Dept.)

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Saturn the ringed Planet
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Saturn is a Jovian Planet
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Comparison

• Jovian
• far from the Sun
• widely spaced orbits
• large radii
• large masses
• predominantly gaseous
• low density
• no solid surface
• many moons
• many rings

• Terrestrial
• close to the Sun
• closely spaced orbits
• small radii
• small masses
• predominantly rocky
• high density
• solid surface
• few moons
• no rings

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Saturns Atmosphere

• 92 Hydrogen 7 Helium some methane, water,
  ammonia
• Belt structure similar to Jupiters, but fainter
• Storms are rarer
• White spot seen, 1990 (Voyager)

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Aurora Borealis and Australis on Saturn
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Ring Systems
Saturn
Uranus
Neptune
Jupiter
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Saturns Rings

• Rings composed of small, icy fragments, orbiting
  in concentric circles
• James Clerk Maxwell confirmed by James Keeler
  (1895) using Doppler shift
• Orbits obey Keplers laws (of course!)
• Inner rings move faster than outer ones

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Visibility of Saturns Rings
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Changing Ring Opening
2000
1999
1998
1997
1996
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How Do They Form?

• Miscellaneous debris
• Moons or other small bodies torn apart by tidal
  forces
• Roche limit distance inside of which an object
  held together by gravity will be pulled apart

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Rings and Shepherd Moons
Shepherd moons
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Ring Formation

• Rings may be short lived (on the time scale of
  solar system)
• Means that they must form fairly frequently
• A moon may pass too close to a planet (within the
  Roche limit) and be destroyed by tidal forces
• This will probably happen to Triton (a moon of
  Neptune) within 100 million years!

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Saturns Moons
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Saturns Moons

• Two-faced looks like Star Wars
  Death Star
• We saw
  these three
  plus Titan at
  rooftop

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Weitkamp Observatory Picture

• Saturn (March 9, 2004, 2050 EST)
• (Photographed with the LX200 10, and
  departments Sony DSC F-717 Digital Camera)

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Saturns Moons from the Roof
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Titan

• Titan is the only moon in the solar system known
  to have an atmosphere
• Infrared picture shows surface details

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Double-faced Japetus

• Extremely different surface reflectivity
• Probably dust

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Space ProbesVoyager Pioneer

• Pioneer 10
• launched in early 1970ies
• Still alive
• Voyagers launched 1977
• Jupiter 1979
• Saturn 1981
• Uranus 1986
• Neptune 1989

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The Grand Tour

• Small
• window of
• opportunity
• in 1977

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Leaving the Solar System

• Voyager 1
• 8.6 billion miles (95 AU) out
• Speed 3.6 AU/year

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The Sounds of Earth Message to the Aliens

• On the chance that someone is out there, NASA
  approved the placement of a phonograph record on
  each of the Voyager spacecraft. The recording,
  called "Sounds of Earth" fits on a 12-inch,
  copper disc containing greetings from Earth
  people in 60 languages, samples of music from
  different cultures and eras, and natural sounds
  of surf, wind and thunder, and birds, whales and
  other animals. The record also contains
  electronic information that an advanced
  technological civilization could convert into
  diagrams, pictures and printed words, including a
  message from President Carter. (Courtesy NASA)

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• Cassini NASA space probe
• Huygens ESA lander

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Cassini at Saturn a Picture Harvest
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Phoebe Saturns Outpost
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A Look through the Rings
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Rheas Bright Splat

• Rhea (949 mi)
• Cassini photo from 1.3 million miles

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• Visible here are Mimas (397 kilometers, or 247
  miles across) near lower right Janus (181
  kilometers, or 113 miles across) below the F
  ring and Enceladus (505 kilometers, or 314 miles
  across) at lower left.

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Hyugens at Titan

• STRANGE TITAN Get ready for two of the strangest
  hours in the history of space exploration. That's
  how long it will take the European Space Agency's
  Huygens probe to parachute to the surface of
  Saturn's largest moon Titan on January 14th,
  2005. Huygens will sample Titan's atmosphere,
  photograph its bizarre terrain, listen for alien
  sounds and, possibly, splash down in a liquid
  methane sea.

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Surface of Titan
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(No Transcript)
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Titan from 10 km
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360 Panorama of Titan
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(No Transcript)
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Titans thick atmosphere

• made up of nitrogen and methane
• extremely cold -290 degrees Fahrenheit
• Scientists believe Titan's atmosphere may be
  similar to that of the primordial Earth and
  studying it could provide clues to how life
  began.

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Titans Atmosphere
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The Night Sky in June

• The sun is at its highest -gt shortest nights!
• Summer constellations are coming up Hercules,
  Scorpius, Ophiuchus (Snake Bearer), Snake
• ? lots of globular star clusters!
• Center of the Milky Way in Sagittarius
• Jupiter is in the South at sunset

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Moon Phases

• Today (Waning crescent, 0)
• 6 / 6 (New Moon)
• 6 / 14 (First Quarter Moon)
• 6 / 22 (Full Moon)
• 6/ 28 (Last Quarter Moon)

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Today at Noon

• Sun at meridian, i.e. exactly south

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10 PM
Saturn sets

• Typical observing hour, early March
• no Moon
• Jupiter past meridian
• Pluto (experts only)

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South-West

• Virgo and
• Coma
• with the Virgo-Coma galaxy cluster

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Virgo-Coma Cluster

• Lots of galaxies within a few degrees

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M87, M88 and M91
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Zenith

• Big Dipper points to the north pole

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South

• Canes Venatici
• Corona Borealis
• Bootes
• Serpens

• Globular Star
• Clusters
• M 3
• M 5
• M 13

• Galaxies
• M 51
• M 101
• M 64 (Bl. Eye)

M 5
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South-East

• Hercules
• Ophiuchus
• Serpens

• Globular Star
• Clusters
• M 13
• M 92
• M 12
• M 10

Summer is Globular Cluster time!
M 5
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M13 Globular Cluster
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South-East

• Ophiuchus
• Serpens
• Scorpius

• Globular Star
• Clusters
• M 4
• M 19
• M 62
• M 80

Summer is Globular Cluster time!
M 5
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Summer Break Mark your Calendars for Fall!

• Next Starry Monday at Otterbein October 3, 2005,
  7 pm
• (this is a Monday
  )
• Web pages
• http//www.otterbein.edu/dept/PHYS/weitkamp.asp
  (Obs.)
• http//www.otterbein.edu/dept/PHYS/ (Physics
  Dept.)

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Mark your Calendars II

• Physics Coffee is every Wednesday, 330 pm
• Open to the public, everyone welcome!
• Location across the hall, Science 256
• Free coffee, cookies, etc.
• Will also return in the Fall!