Transcript Slide 1

Class Update
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Observations
• Friday, Mar.5
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8-9:30pm University of Minnesota (Telescopes, Star Gazing & Moon
Craters) PRINT VERIFICATION SHEET
Saturday, Mar. 14
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Spring Break
No class next week
7-10pm MN Astronomical Society at Eagle Lake Observatory,
Norwood-Young America (Telescopes, Star Gazing & NO MOON
CRATERS) No verification sheet needed. Raquel and Gus present.
Call/text tutor Gus for a ride 954-670-3713; meet at 6pm at Café
Espresso Royale
$5 per car
Lab Dimensional Analysis & Significant Figures Quiz Mar. 3 or
5 depending on your lab section & day (open notebook)
Mars & Saturn Writing Assignment due Mar. 24 with Test 2
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Work on this over spring break (more details on calendar)
What’s in our solar system?
*Sun
*Planets
Terrestrial
Jovian
Dwarf
Small Solar System Bodies
*Meteoroids
*Comets
Dust
http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg
*Sun
a. Most of mass (>99%) of solar system
b. Star – produces own energy by fusion
c. Hot
http://sohowww.nascom.nasa.gov/gallery/images/large/eit001_prev.jpg
What’s in our solar system?
*Sun
*Planets
Terrestrial
Jovian
http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg
**KNOW THIS**
Terrestrial
“Earth-like”
• Small, less massive
• Close to Sun (warm)
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Heavy elements
High density
Solid Surfaces
Cratered
Few moons
Thin atmospheres
Weak magnetic fields
Slow rotation
Fast revolution (Kepler)
Jovian
“Jupiter-like”
• Large, massive
• Far from Sun (cold)
• Rings
• Big storms, turbulent atmosphere,
belt rotation
• Hydrogen rich (light elements)
• Low density
• Gas and Liquid
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Many moons
Thick atmospheres
Large magnetic fields (some tilted)
Fast rotation
Slower revolution
Terrestrial
Jovian
Assignment:
• Highlights of Mars and Saturn
• See class website calendar for details
• 20 points on next test
• At least 10 sentences covering 10 highlights
– 5 for Mars and 5 for Saturn
• Print and bring to test 2 on 3/24/15
What’s in our solar system?
*Sun
*Planets
Terrestrial
Jovian
Dwarf
http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg
What objects are planets and dwarf planets?
Question
Orbits Sun?
Round?
Not a moon?
Cleared orbit?
Not cleared orbit?
International Astronomical Union 2006
http://www.iau.org/news/pressreleases/detail/iau0603/
Planet
X
X
X
X
Dwarf Planet
X
X
X
X
Plutoids
Dwarf Planets
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Ceres
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Pluto
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Eris
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Makemake
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Haumea
Pluto Location
PlutoHard to
classify
Keberus
http://apod.nasa.gov/apod/ap120716.html
Styx
Pluto: Planet or ?
• Round
• Moons
• Orbit tilted to plane of solar system
• Orbit more elliptical than other planets
• Sometimes Pluto is closer to sun than Neptune
• Denser than Jovians, less dense than Terrestrials
• One of many objects orbiting sun beyond Neptune
Eris
44o orbit inclination
Highly elliptical orbit
July 2005 at 97 AU
Sep 2005 It has a moon.
Dwarf Planet Locations
Other problem objects
Large meteoroids (asteroids)
Asteroid Belt between Mars and Jupiter
http://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/Eris_
Orbit.svg/644px-Eris_Orbit.svg.png
Ceres (largest
object in asteroid
belt)
Orbits sun
Round
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~600 mi
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Part of
neighborhood of
other objects
=Dwarf Planet
Better pictures and video from DAWN – more coming in 2015
http://www.universetoday.com/119235/bright-spots-on-ceres-likelyice-not-cryovolcanoes/#more-119235
http://hubblesite.org/newscenter/newsdesk/archive
/releases/2005/27/image/a
*Planet
Terrestrial (small, dense…)
Jovian (large, gaseous…)
Dwarf
Current definition of Dwarf Planet
a. *Orbits a star
b. *Round by own gravity
c. *Has not cleared its neighborhood
Dwarf Planets
1. Pluto
2. Eris
3. Haumea
4. Makemake
5. Ceres
Dwarf
Planets
Dwarf Planet
Candidates
Image: NASA
Dwarf Planet Locations
Asteroid Belt
Kuiper Belt
Show solar system simulator
Image: NASA
What’s in our solar system?
*Sun
*Planets
Terrestrial
Jovian
Dwarf
Small Solar System Bodies
*Meteoroids
*Comets
Dust
http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg
Small Solar System Bodies
*Meteoroids
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Definition: rocky matter in space
Small, rocky, oblong
Mostly between Mars and Jupiter
(Asteroid Belt)
Asteroid – larger meteoroid
*Comets
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Icy
Some from beyond Neptune - Kuiper
Belt Objects (40 AU)
Some from farther out (1/4 way to next
star) - Oort Cloud (1LY=63000AU)
http://herschel.jpl.nasa.gov/solarSystem.shtml
Kuiper Belt –
Many icy, rock
objects beyond
Neptune
Asteroid Belt –
Cluster of
meteoroids
between Mars
and Jupiter
Oort Cloud –
Icy matter,
including
many comets
way out here
http://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/Eris_
Orbit.svg/644px-Eris_Orbit.svg.png
Meteoroids/Asteroids
*Orbit the sun
 *Mostly between Mars
and Jupiter (Some
throughout the solar
system)
 *Rocky, sometimes icy
 *Most are oblong
 *Larger ones often
called asteroids
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Gaspra
*Meteoroids
Small (grain size) to Minnesota size
Largest asteroid,
Ceres, at ~600 mi.
is a dwarf planet
 2nd largest asteroid,
Vesta, at ~300 mi.
but not as round or
massive, so it
remains an asteroid
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Vesta
2nd Largest Object in Asteroid Belt
Planet or Dwarf planet or Asteroid?
Vesta
http://apod.nasa.gov/apod/ap120919.html
Examples of
Asteroids/meteoroids
Gaspra
http://www2.jpl.nasa.gov/galileo/images/gaspra.gif
12 mi X 7 mi
Mathilde
Gaspra
~12mi X 7 mi
Ida
Gaspra
(asterioid)
Phobos
(moon)
Deimos (moon)
Deimos
http://antwrp.gsfc.nasa.gov/apod/ap090316.html
Lutetia from Rosetta/ESA
~100 km diameter
http://www.esa.int/esa-mmg/mmg.pl?b=b&type=I&mission=Rosetta&single=y&start=4
Ida and Dactyl
36mi X 14 mi
http://antwrp.gsfc.nasa.gov/apod/ap990807.html
Eros 21 mi
NEAR Shoemaker
Mathilde
37 mi x 29 mi
Crater 20 mi wide X 6 mi deep
Detail 1200 ft
Asteroid Itokawa
Mission Hayabusa
http://www.isas.jaxa.jp/e/snews/2005/1102.shtml
*Meteoroid-
*Meteor-
*Meteorite-
Matter orbiting in
space
Matter glowing
in Earth’s
atmosphere
Meteor on
Earth
*Asteroid – Larger meteoroids
*Meteor (Shooting star, falling star)
*Small (grain to pea size)
 Fast (~50 mi/s)
 Nearby (40 to 80 miles)
 Collide with Earth’s atmosphere, glow
 Most do not reach ground in tact
 Add thousands of tons to Earth each year
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Fireball
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Larger (marble size+)
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Basketball size+ can
reach ground
Chelyabinsk Meteor
Still from a video of the Chelyabinsk meteor streaking across the sky. The video is available at
https://www.youtube.com/watch?v=SMnZr5DDRlA
Why study meteorites?
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*Composition and origin of Moon, Mars,
and asteroids
Why study meteorites?
*Estimate
origin and age
of our solar
system
(4.6 billion yrs)
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Why study meteorites?
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*Origin of life
Murchison
meteorite
(1969)
Why study meteorites?
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*Possible catastrophes for us
Why study meteorites?
*Summary:
 Composition of Moon, Mars, & asteroids
 Estimate origin and age of solar system
 Origin of life
 Possible catastrophes for us
Barringer Crater in Winslow, AZ
Meteor Crater in Winslow, AZ
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Barringer Crater
Crater: 4/5 mile across, ~500 feet deep
Occurred ~50 000 years ago
Energy ~ 20 Megatons of TNT
Original meteor ~ house size, 300 000 tons
Speed 40 000 mi/h
Types of meteorites
Iron-Nickel
Stony-Iron
Samples
Stony
*Comets
*cosmic snowball
* frozen gas, rock and dust
*icy, fuzzy appearance, tail
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Bayeux Tapestry
Comets
*Hang in sky
for days/weeks
Comet McNaught
http://antwrp.gsfc.nasa.gov/apod/ap070212.html
Credit & Copyright: Minoru Yoneto
Comet – orbit
• *Most have
elliptical orbits
• *Some in plane
of solar system
but some not
*Comet –
why do we see them?
1. Nears Sun &
melts
2. Debris reflects
sunlight
3. Sunlight blows
debris away
Interactive comet orbit at
http://www.windows.ucar.edu/tour/link=/comets/comet_model_interactive.html
*Comet Parts
Nucleus = Dense center
Tail = gas/ice/dust
blown back by sun
Head = Nucleus +
surrounding
gas/ice/dust
(Head and tail look dense but are not)
Comet Nucleus–
Old Description
Frozen, dirty
iceberg
Comet Borrelly
http://photojournal.jpl.nasa.gov/target/Other?subselect
=Target:Borrelly:
Comet Nucleus–
New Description
*Many are frozen,
dirty icebergs
*Others are loose
collections of
ice, gas, dust
(ShoemakerLevy 9 - 1993)
APOD –
Wild 2
Comet Tempel 1
Size: ~1/3 Manhattan ~8kmX5km
Average Comet Size (nucleus): few miles
Size ~ 1/2 Manhattan (14kmX4km)
Average
Comet Tail: millions of miles
Comet Parts
Tail: Ions, gas, dust blown
away by sun
*Two tails:
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Gas tail – Ions and gas, blown
straight back from Sun (white)
Dust tail – Lags behind so
looks curved (blue)
Period of Comet
*Long Period comets
Out of plane
Hale-Bopp (~4000 yr)
http://www.eso.org/outreach/info-events/halebopp/comet-hale-bopp-summary-apr07-97-rw.html
*Short Period comets
In plane of solar system
Halley (76 yr),
Tempel-Tuttle (33 yr)
Comet Orbit
Most have very elliptical orbits
 Short period comets generally orbit in the
plane of the solar system
 Long period comets orbit from all
directions
 Suggests two “hideouts” or origins
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*Comet “Hideouts”
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Oort Cloud
 ~ 100 000 AU (~1 LY)
 long period comets,
out-of-plane of SS
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Kuiper Belt
 ~ 40 – 1000 AU
 Kuiper Belt Objects
(KBOs)
 short period comets,
in-plane of SS
Comet “Hideouts”
*Why study comets?
Water carriers?
 Original material of solar system
 Life?
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Rosetta and Philae at
Comet 67P/Churyumov-Gerasimenko
http://www.universetoday.com/119296/dust-whirls-swirls-and-twirls-at-rosettas-comet/
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Reminder: Meteors and comets seen for
different reasons
Meteors:
In Earth’s
atmosphere
Comets:
Not in Earth’s
atmosphere
*Meteor Shower
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Comet leaves
trail of ice and
dust
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Earth sweeps
through the
comet dust
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See 10s to
100s of
meteors per
hour
http://astrobob.areavoices.com/2011/10/19/orionid-meteor-showercould-make-your-wildest-dreams-come-true/
Meteor showers
Best ones
 Perseids Aug 10-14
 Leonids
Nov 14-19
 Geminids Dec 10-13
http://www.youtube.com/watch?v=6XTBrYWrey0
Meteor Streak from Meteor Shower
http://www.jpl.nasa.gov/asteroidwatch/meteor.php
What’s in our solar system?
*Sun
*Planets
Terrestrial
Jovian
Dwarf
Small Solar System Bodies
*Meteoroids
*Comets
Dust – small particles in the cosmos
http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg
Next Lecture
Greenhouse Gasses
Threats to Our Environment
- Dinosaur Extinction