Solar System “Fluff” Pt. 2The fluffier fluff.

Comets.Snowballs of DOOM!!!

Anatomy of a cometNucleus (1 – 100 km)

Coma (100,000 km)

Tails (1 – 500 million km)Dust Tail Ion Tail

Hydrogen Envelope (Cloud)10 million – 100 million km

The Nucleus

Heart of the comet

Consists of:Dust Ice (H2O)

Other ices (CO2, CH4, NH3, etc.)

Can appear VERY dark! (<10% reflectivity)

The Coma

Dense “Atmosphere” of materials surrounding nucleus.

Consists of vaporized materials from the nucleus as the comet approaches the sun

Comets have extremely low gravity Cant keep the material close, or even

hang on for long!

The Coma can be larger than the sun!

Ion Dust

The Tails!

Gases from comet ionized by UV from sun

Magnetic field from solar wind pushes them back

Solar photons strike the material from the coma

This tail curves, due to the comets motion

Halley’s

Trans-neptunian objects (TNO)

• ANY object that is part of the solar system and beyond the orbit of Neptune.

• Three subcategories• Kuiper Belt• Scattered Disc:• Oort Cloud:

• All objects are primarily Icy, with frozen volatiles (methane, ammonia, etc.), some rock

The Kuiper Belt• Consists of Objects from 30 – 50 A.U

• KBO = Kuiper Belt Object

• Hypothesized in 1930• Discovered in 1987

• Over 100,000 KBOs larger than 100km

• Most are resonant with Neptune’s orbit

The Scattered DiscRegion primarily beyond the Kuiper Belt

Dynamic – objects are not locked into

resonance like KBOsMost comets are believed to

originate from this region

First designated in the late 90’sOnly very recently officially

accepted

A sampling

more

The Oort cloud

• Farthest reaches of the solar system

• Objects up to 1 light year away (50,000 A.U.)

• Spherical in structure, instead of flat, disc shaped regions

• May have formed as a result of interactions with nearby stars• (pulling objects out from the solar system)

Orbits of comets

HIGHLY elliptical

Bringers of Life (not doom)

Many impacts of early earth were comets

Thought to have contributed 3 things to early EarthWater (comets are very icy)Organic molecules (Comets contain precursors)Perhaps even fully formed amino acids

Much research is still being done.

Mission: Deep Impact

impact

impact

Shoemaker-levy

Hyakutake

360 million km tail

Not a spaceship…

Hale-Bopp