Post on 19-Jan-2016
transcript
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