Class Update• Observations

• Friday, Mar.5• 8-9:30pm University of Minnesota (Telescopes, Star Gazing & Moon

Craters) PRINT VERIFICATION SHEET

• Saturday, Mar. 14• 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• Work on this over spring break (more details on calendar)

Spring BreakNo class next week

What’s in our solar system?

http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg

*Sun*Planets

TerrestrialJovianDwarf

Small Solar System Bodies *Meteoroids *CometsDust

*Sun a. Most of mass (>99%) of solar systemb. Star – produces own energy by fusionc. Hot

http://sohowww.nascom.nasa.gov/gallery/images/large/eit001_prev.jpg

What’s in our solar system?

http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg

*Sun*Planets

TerrestrialJovian

Terrestrial“Earth-like”• Small, less massive• Close to Sun (warm)

• 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

• Many moons• Thick atmospheres• Large magnetic fields (some tilted)• Fast rotation• Slower revolution

**KNOW THIS**

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?

http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg

*Sun*Planets

TerrestrialJovianDwarf

What objects are planets and dwarf planets?

International Astronomical Union 2006http://www.iau.org/news/pressreleases/detail/iau0603/

Question Planet Dwarf Planet

Orbits Sun? X X

Round? X X

Not a moon? X X

Cleared orbit? X

Not cleared orbit? X

Dwarf Planets

Ceres

Pluto

Eris

Makemake

Haumea

Plu

toid

s

Pluto Location

Pluto-Hard to classify

http://apod.nasa.gov/apod/ap120716.html

StyxKeberus

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

44o orbit inclination Highly elliptical orbit

July 2005 at 97 AU Sep 2005 It has a moon.

Eris

Dwarf Planet Locations

http://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/Eris_Orbit.svg/644px-Eris_Orbit.svg.png

Other problem objects

Large meteoroids (asteroids)

Asteroid Belt between Mars and Jupiter

http://hubblesite.org/newscenter/newsdesk/archive/releases/2005/27/image/a

Ceres (largest object in asteroid belt)

Orbits sun

Round

Part of neighborhood of other objects

=Dwarf Planet

~600 mi

Better pictures and video from DAWN – more coming in 2015http://www.universetoday.com/119235/bright-spots-on-ceres-likely-ice-not-cryovolcanoes/#more-119235

*PlanetTerrestrial (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 Planets1. Pluto2. Eris3. Haumea4. Makemake 5. Ceres

Image: NASA

Dwarf Planets

Dwarf PlanetCandidates

Haumea

Show solar system simulator

Image: NASA

Asteroid Belt Kuiper Belt

Dwarf Planet Locations

What’s in our solar system?

http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg

*Sun*Planets

TerrestrialJovianDwarf

Small Solar System Bodies *Meteoroids *CometsDust

*Meteoroids Definition: rocky matter in space Small, rocky, oblong Mostly between Mars and Jupiter

(Asteroid Belt) Asteroid – larger meteoroid

*Comets Icy Some from beyond Neptune - Kuiper

Belt Objects (40 AU) Some from farther out (1/4 way to next

star) - Oort Cloud (1LY=63000AU)

Small Solar System Bodies

http://herschel.jpl.nasa.gov/solarSystem.shtml

http://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/Eris_Orbit.svg/644px-Eris_Orbit.svg.png

Asteroid Belt – Cluster of meteoroids between Mars and Jupiter

Kuiper Belt – Many icy, rock objects beyond Neptune

Oort Cloud – Icy matter, including many comets way out here

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

Gaspra

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

*MeteoroidsSmall (grain size) to Minnesota size

Vesta2nd Largest Object in Asteroid BeltPlanet or Dwarf planet or Asteroid?

http://apod.nasa.gov/apod/ap120919.html

Vesta

http://www2.jpl.nasa.gov/galileo/images/gaspra.gif12 mi X 7 mi

Examples of Asteroids/meteoroids

Gaspra

Mathilde Gaspra

~12mi X 7 mi

Ida

Gaspra (asterioid)

Deimos (moon)

Phobos (moon)

Deimos http://antwrp.gsfc.nasa.gov/apod/ap090316.html

Lutetia from Rosetta/ESA

~100 km diameterhttp://www.esa.int/esa-mmg/mmg.pl?b=b&type=I&mission=Rosetta&single=y&start=4

36mi X 14 mihttp://antwrp.gsfc.nasa.gov/apod/ap990807.html

Ida and Dactyl

Eros 21 mi

NEAR Shoemaker

37 mi x 29 mi Crater 20 mi wide X 6 mi deepDetail 1200 ft

Mathilde

http://www.isas.jaxa.jp/e/snews/2005/1102.shtml

Asteroid Itokawa

Mission Hayabusa

*Meteorite-

Meteor on Earth

*Meteoroid-

Matter orbiting in space

*Meteor-

Matter glowing in Earth’s atmosphere

*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 tactAdd thousands of tons to Earth each year

Fireball Larger (marble size+) 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?

*Composition and origin of Moon, Mars, and asteroids

Why study meteorites?

*Estimate origin and age of our solar system

(4.6 billion yrs)

Why study meteorites?

*Origin of life

Murchison meteorite (1969)

Why study meteorites?

*Possible catastrophes for us

Why study meteorites?

*Summary:Composition of Moon, Mars, & asteroidsEstimate origin and age of solar systemOrigin of lifePossible catastrophes for us

Barringer Crater in Winslow, AZ

Meteor Crater in Winslow, AZ

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

Samples

Iron-Nickel

Types of meteorites

Stony-Iron Stony

*Comets*cosmic snowball

* frozen gas, rock and dust*icy, fuzzy appearance, tail

Bayeux Tapestry

Comets*Hang in sky for days/weeks

Comet McNaughthttp://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

Tail = gas/ice/dust blown back by sun

Nucleus = Dense center

Head = Nucleus + surrounding gas/ice/dust

*Comet Parts

(Head and tail look dense but are not)

Frozen, dirty iceberg

Comet Borrelly

http://photojournal.jpl.nasa.gov/target/Other?subselect=Target:Borrelly:

Comet Nucleus– Old Description

Comet Nucleus– New Description

*Many are frozen, dirty icebergs

*Others are loose collections of ice, gas, dust (Shoemaker-Levy 9 - 1993)

APOD – Wild 2

Size ~ 1/2 Manhattan (14kmX4km)

Comet Tempel 1

Size: ~1/3 Manhattan ~8kmX5km

Average Comet Size (nucleus): few milesAverage Comet Tail: millions of miles

http://apod.nasa.gov/apod/ap110216.html

Comet Parts

Tail: Ions, gas, dust blown away by sun

*Two tails: Gas tail – Ions and gas, blown

straight back from Sun (white) Dust tail – Lags behind so

looks curved (blue)

Period of Comet*Short Period comets In plane of solar system Halley (76 yr), Tempel-Tuttle (33 yr)

*Long Period comets Out of plane Hale-Bopp (~4000 yr)

http://www.eso.org/outreach/info-events/hale-bopp/comet-hale-bopp-summary-apr07-97-rw.html

Comet Orbit

Most have very elliptical orbitsShort period comets generally orbit in the

plane of the solar systemLong period comets orbit from all

directionsSuggests two “hideouts” or origins

*Comet “Hideouts” Oort Cloud

~ 100 000 AU (~1 LY) long period comets,

out-of-plane of SS

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 systemLife?

Rosetta and Philae at Comet 67P/Churyumov-Gerasimenko

http://www.universetoday.com/119296/dust-whirls-swirls-and-twirls-at-rosettas-comet/

Reminder: Meteors and comets seen for different reasons

Meteors: In Earth’s atmosphere

Comets: Not in Earth’s atmosphere

*Meteor Shower Comet leaves

trail of ice and dust

Earth sweeps through the comet dust

See 10s to 100s of meteors per hour

http://astrobob.areavoices.com/2011/10/19/orionid-meteor-shower-could-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?

http://www.techastronomy.com/UserFiles/2007/7/22/solar_system4(1).jpg

*Sun*Planets

TerrestrialJovianDwarf

Small Solar System Bodies *Meteoroids *CometsDust – small particles in the cosmos

Next Lecture

Greenhouse Gasses

Threats to Our Environment - Dinosaur Extinction