sun : terrestrial planets : jovian planets

Sun : Terrestrial planets : Jovian planets

5 AU

50 AU

500 AU

50,000 AU

Comet McNaught from Australia (January 2007)

Dust tail

Hydrogen envelope

Ion tail

Nucleus

Coma

Comet Halley (1986) Comet Hartley2 (2010)

Comet Nuclei

Comet Holmes (2007) : Coma and ion tail

Comet Hale-Bopp (1997) : dust tail and ion tail

Earthgrazer: The Great Daylight Fireball of 1972

Car damaged by Peekskill meteor (shown below)

Impact sites discovered since 1980

Chicxulub crater, Yucatan Peninsula, Mexico – 65 MY

Clearwater Lakes, Quebec, Canada – 290 MY

Meteor Crater AZ – 40,000 years

1200 meters

Torino Scale: Impact hazard associated with NEO

Kin

etic

Ene

rgy

(MT)

Impact probability

108

105

100

1

10-8 10-6 10-4 10-2 >0.99

No concern – Pay attention – Threatening – Certain impact

Meteorites

Stony Stony-Iron (pallasites)

Irons

Meteorites

Stony Stony-Iron (pallasites)

Irons

Achondrites Chondrites

Meteorites

Stony Stony-Iron (pallasites)

Irons

Achondrites Chondrites

Ordinary Chondrites

Carbonaceous Chondrites

Iron meteorite

Pallasite meteorite

Ordinary stone Meteorite

Achondrite

Ordinary Chondrite

Chondrule

Carbonaceous Chondrite

Primitive stones 52 87 85 (chondrites) Differentiated stones 1 9 12 Irons 42 3 2 Stony Irons 5 1 1 (pallasites)

Meteorite Abundances (%)

Finds Falls Antarctic

Primitive stones 52 87 85 (chondrites) Differentiated stones 1 9 12 Irons 42 3 2 Stony Irons 5 1 1 (pallasites)

Meteorite Abundances (%)

Finds Falls Antarctic

Primitive stones 52 87 85 (chondrites) Differentiated stones 1 9 12 Irons 42 3 2 Stony Irons 5 1 1 (pallasites)

Meteorite Abundances (%)

Finds Falls Antarctic

Primitive stones 52 87 85 (chondrites) Differentiated stones 1 9 12 Irons 42 3 2 Stony Irons 5 1 1 (pallasites)

Meteorite Abundances (%)

Finds Falls Antarctic

2004 FH

3753 Cruithne

1 Ceres 940

2 Pallas 580

4 Vesta 550

10 Hygeia 440

107 Camilla 250

87 Sylvia 225

12 Victoria 115

8 Flora 150

433 Eros 7x20x30

3476

4 Vesta

21 Lutetia

253 Mathilde

243 Ida (243) Ida 1 Dactyl

433 Eros

951 Gaspra

2867 Steins

25143 Itokawa

243 Ida

Dactyl

Kirkwood Gaps N

umbe

r of a

ster

oids

(p

er 0

.005

AU

bin

)

Distance (AU)

4:1 3:1 2:1

Kirkwood Gaps N

umbe

r of a

ster

oids

(p

er 0

.005

AU

bin

)

Distance (AU)

4:1 3:1 5:2 7:3 2:1

Kirkwood Gaps N

umbe

r of a

ster

oids

(p

er 0

.005

AU

bin

)

Distance (AU)

4:1 3:1 5:2 7:3 2:1 11:5

Kirkwood Gaps N

umbe

r of a

ster

oids

(p

er 0

.005

AU

bin

)

Distance (AU)

4:1 3:1 5:2 7:3 2:1 8:3 11:5

Kirkwood Gaps N

umbe

r of a

ster

oids

(p

er 0

.005

AU

bin

)

Distance (AU)

4:1 3:1 5:2 7:3 2:1 10:3 8:3 11:5

Orbital resonance

25143 Itokawa

Asteroids composition albedo population C-type carbonaceous 0.03 75% S-type Fe + Mg silicates 0.10 – 0.22 17% M-type Fe +Ni alloy 0.10 – 0.18 8%

S M C

popu

latio

n

Distance (AU) 2.0 2.5 3.0 3.5

S M C