Study Points⚫ What is the major difference between a

planet and a dwarf planet?

⚫ Name a dwarf planet.

⚫ Where are the dwarf planets in our solar

system?

⚫ Distinguish between a meteor, a

meteorite, and a meteoroid.

⚫ What is a "shooting star"? Why do we

see it? On average, how big is one?

⚫ Why do we study meteorites?

⚫ What is a comet?

⚫ Describe a comet including the nucleus,

head and tail. Why do we see a comet?

⚫ Roughly, how big are comets?

⚫ What is the Asteroid Belt? the Oort

Cloud? the Kuiper Belt? Where is each

located?

⚫ Why study comets?

⚫ What is a meteor shower? What is the

comet connection to a meteor shower?

What’s in our solar system?

Sun

Planets

Terrestrial

Jovian

Dwarf

Small Solar System Bodies

Meteoroids

Comets

Dust

Sun (future lecture after Test 2 all about the 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?

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

Sun

Planets

Terrestrial

Jovian

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**From Last Lecture:

Terrestrial Jovian

Writing Assignment – Part of Test 2:

• Planet Highlights – 1 Terrestrial & 1 Jovian

• See class website calendar for details

• 20 points on next test

• 5 Highlights for each planet

• Print and bring to Test 2

What’s in our solar system?

Sun

Planets

Terrestrial

Jovian

Dwarf

What objects are planets and dwarf planets?*

International Astronomical Union 2006

http://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

⚫ Ceres (Asteroid Belt)

⚫ Pluto

⚫ Eris

⚫ Makemake

⚫ Haumea

Dwarf Planets*P

luto

ids

Haumea⚫ Telescopes discovered: DWARF PLANET

HAUMEA HAS A RING (10/11/2017)⚫ https://www.universetoday.com/137444/dwarf-planet-haumea-ring/

Pluto Location

Pluto Orbit

https://spaceplace.nasa.gov/ice-dwarf/en/

Pluto-

Hard to

classify

Pluto and

its largest

moon,

Charon

(top left)

https://www.nasa.gov/feature/pluto-s-big-moon-charon-reveals-a-colorful-and-violent-history

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

StyxKeberus

Watch Motion Video of Pluto’s 5 Moons

https://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-pluto-k4.html

Pluto Moons

https://spaceplace.nasa.gov/ice-dwarf/en/

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

• It is a Dwarf Planet

What are the names of the 2

areas in our solar system with

asteroids or meteoroids?*

⚫ 1.

⚫ 2.

⚫ And where is each located?*

⚫ 3. location of 1. =

⚫ 4. location of 2. =

Other Problem Objects

Large meteoroids (asteroids)

Asteroid Belt between Mars and Jupiter

Ceres (largest object in

asteroid belt)

Orbits sun

Round

Part of neighborhood of

other objects

=Dwarf Planet

~600 mi →

Pictures and video from DAWN

http://solarsystem.nasa.gov/planets/ceres

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

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

Terrestrial

Jovian

Dwarf

Small Solar System Bodies

Meteoroids

Comets

Dust

Meteoroids

▪ Definition: rocky matter in space*

▪ Small, rocky, oblong

▪ Mostly between Mars and Jupiter

(Asteroid Belt)

▪ Asteroid – larger meteoroid

Comets

▪ Definition: Icy object orbiting Sun*

▪ 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

Planet 9?• Part of Kuiper Belt and

influences other orbits

• Video here with more

info if interested:• http://www.universetoday.com/133555/pl

anet-9-cant-run-forever-two-asteroids-

give-clues/

http://www.universetoday.com/wp-

content/uploads/2016/03/Planet_Nine

_animation.gif

The Goblin – Potential Dwarf Planet

http://earthsky.org/space/new-dwarf-planet-the-goblin-planet-x

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

⚫ Dwarf Planet

(Largest in asteroid

belt), 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/rice size) is most common*Largest is up to Minnesota size

Vesta2nd Largest Object in Asteroid Belt

Planet or Dwarf planet or Asteroid?

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

Vesta

Lutetia from Rosetta/ESA

~120 km diameter (~70 mi)

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

Mathilde Gaspra

~12mi X 7 mi

Ida

Gaspra

(asterioid)

Deimos (Mars’ moon)

Phobos

(Mars’ moon)

36mi X 14 mi

http://antwrp.gsfc.nasa.gov/apod/ap990807.html

Ida and Dactyl

Eros 21 mi

NEAR Shoemaker

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

Asteroid Itokawa

Japan’s Hayabusa

2005-10

Japan’s Hayabusa2 - 2018

⚫ Watch https://www.nbcnews.com/mach/science/watch-japan-s-

hayabusa-2-spacecraft-touch-down-asteroid-ncna979756

Landed on asteroid Feb. 2019

⚫ 2 Bouncing rovers

⚫ Sample return mission to Earth in 2020

⚫ Picture:

⚫ Itokawa and Ryugu

What are NASA’s asteroid

plans?⚫ NASA asteroid mission

⚫ NASA asteroid spacecraft

Asteroids Visited by Spacecraft

NASA OSIRIS – Rex

Asteroid Sample Return Mission

NASA & ESA DART Mission to

redirect an asteroid

Meteorite*

Meteor on

Earth

Meteoroid*

Rocky (icy)

matter orbiting

the Sun

Meteor*

Matter glowing

in Earth’s

atmosphere

Asteroid – Larger Meteoroid*

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

Fireball

⚫ Larger (marble size+)

⚫ Basketball size+ can

reach ground

Chelyabinsk Meteor

⚫ Feb. 15, 2013, speed of about 40 mi/s or 19 km/s

⚫ 1500 people injured, 13,000 tons, 20 m diameter

⚫ https://www.youtube.com/watch?v=dpmXyJrs7iU

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, & 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

⚫ Barringer Crater

⚫ Crater: 4/5 mile across, ~500 feet deep

⚫ Occurred ~50,000 years ago

⚫ Energy ~ 20 Megatons of TNT

⚫ Original meteor ~ house size (45m), 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, tails

Bayeux Tapestry

CometsHang in sky for

days/weeks*

Comet McNaughthttp://antwrp.gsfc.nasa.gov/apod/ap070212.html

Credit & Copyright: Minoru Yoneto

Comet – orbit

• Most have very 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

creating tail*

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–

Original Description

⚫ Many are

frozen, dirty

icebergs*

⚫ Others are

loose

collections of

ice, gas, dust

(Shoemaker-

Levy 9 - 1993)*

Comet Nucleus–

Additional Description

APOD –

Wild 2

Size ~ 1/2 Manhattan (14kmX4km)

Comet Tempel 1

Size: ~1/3 Manhattan ~8kmX5km

Average Comet Size (nucleus): few miles

Average Comet Tail: millions of miles

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)

Dust tail (blue)

Gas tail (white)

Period of CometShort Period comets*

In plane of solar system

Halley (76 yr),

Tempel-Tuttle (33 yr)

Long Period comets*

Out of planeHale-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 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

Comet “Hideouts”*⚫ Oort Cloud*

⚫ Sphere of frozen material around solar system*

⚫ ~ 100,000 AU (~1 LY)

⚫ long period comets, out-of-plane of SS

⚫ Kuiper Belt*

⚫ Objects in plane of solar system beyond Neptune

⚫ ~ 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?

In 2014 Rosetta and Philae at

Comet 67P/Churyumov-Gerasimenko

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

http://www.esa.int/Our_

Activities/Space_Scienc

e/Rosetta/Rosetta_s_la

nder_Philae_wakes_up

_from_hibernation

Reminder: Meteors and comets are seen for

different reasons

Meteors:

In Earth’s

atmosphere

Comets:

Not in Earth’s

atmosphere

Meteor Shower*connection between meteors and comets

⚫ Comet leaves trail of

ice and dust

⚫ Earth sweeps through

the comet dust

⚫ See 10s to 100s of

meteors per hour

⚫ Meteor Shower

happens when Earth

passes through leftover

comet debris*

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

Watch example here:

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

Terrestrial

Jovian

Dwarf

Small Solar System Bodies

Meteoroids

Comets

Dust – small particles in the cosmos

Next Lecture

Greenhouse Gasses

Threats to Our Environment

- Dinosaur Extinction

Observation Projects

OBSERVATION PROJECTS: 135 points available, 100 pts maxAll Observations due by midnight (11:59pm) on their due date.

You can hand in the observation during class, email a picture by midnight, or

submit on D2L Assignment Submissions.✓ Earth-Sun Scale Model Due Jan. 28 (10 points) Make scaled model & take picture✓ Sunset – Part 1 Due Feb. 18 (10 points) Take 1st picture of sunset (same location)✓ Student Conference Due Feb. 27 (occurs on Feb. 25) (5 points)❖ Moon Phases Due TODAY Mar. 5 (10 points) Observe 4 phases & record in table➢ Planetarium (Plan) Due May 5 (10 points) See a show Feb. 4 (FIELD TRIP)❑ Stargazing (SG) Due May 12 (20 points) Go stargazing & write report❑ Telescope (Tel) Due May 12 (20 points) Look through a telescope ❑ Moon Craters (MC) Due May 12 (10 points) Look at moon craters

FUTURE: (don’t start yet)❑ Astrophysics Lecture or Report Start Mar. 19; Due Apr. 21 (10 points) Attend

lecture Apr. 14 or write report ❑ Sunset – Part 2 Start Apr. 7; Due Apr. 28 (10 pts) 2nd sunset picture, same location❑ Astronomy News Evaluation Start Mar. 31; Due May 5 (20 pts) New report

• Continue answering STUDY POINTS (flashcards)• D2L Quizzes 5-7 open. Quizzes 5-8 for Test 2

• Observations: (weather & calendar update)❑ Moon Phases Due TODAY Mar. 5 (10 pts) Observe 4 phases & record in table

❑ Turn in now or email/D2L submit picture of your table by 11:59pm tonight❑ Stargazing (SG) Due May 12 (20 points) Go stargazing & write report❑ Telescope (Tel) Due May 12 (20 points) Look through a telescope ❑ Moon Craters (MC) Due May 12 (10 points) Look at moon craters

• Lab this week on Dimensional Analysis & Significant Figures• Come to your registered lab time this week. Don’t miss lab. Helpful for

the Lab Quiz in 2 weeks.

• Tutor Oskar in T3200 Mon, Wed, Fri – class website has hours

• Test 2, Tuesday, March 24• 40 multiple choice questions

• 20 points for Planets Writing Assignment – print & bring to test

• Work on this over spring break

• Study by answering Study Points and doing D2L quizzes

• Happy Spring Break next week – work on writing assignment

Homework & Observations