EAS206 Lecture Notes - Lecture 21: Kuiper Belt, Solid Nitrogen, Plain
30 Apr 2018
School
Department
Course
Professor
New Horizons
• Has everything you need to image the object in visible and IR and UV light on the
spectrum
Kuiper Belt
• Trans-Neptunian orbits (beyond the orbit of Neptune)
• May of these ojets are ery dark = lo aledo, do’t reflet ery ell so hard to
pick up
Kuiper Belt Objects
• Very big objects (six others)
• Range in albedo and colour
o Different compositions? Geologic differences
• Sedna
o Inuit goddess of the sea = frigid temperatures
o Perihelion = closest part to the Sun
▪ Does’t ee oe lose to the Solar syste
• So that means not only do we have objects that are very large, but we also have
objects that have been moved out of their original orbit (started like Pluto but has
been shifted since)
Pluto – Charon System
• What was known before New Horizons
o Pluto’s orit oes ithi the orit Neptue (loser to the Su for a rief
period)
▪ Resonance with Neptune (3:2 ratio) = never collide
• For every 2 times Neptune goes around, Pluto goes around 3
times
o Pluto’s orit rage fro 0 AU to 8 AU
• Stable orbit ratios
o As you freeze out the atmosphere that the nitrogen snows out onto the
surface. As it gets closer to the sun, it becomes a gas again
o Pluto and Charon is tidally locked
• Nearly featureless
o Thought that it was an ancient surface, undifferentiated with lots of craters
o Northern Hemisphere
▪ Rift valleys
▪ Craters
• But oe area that does’t have ay craters = resurfacig ad very
young
o Different colours = different composition
o White areas = like Europa
▪ Water ice
• But not water ice = it is instead nitrogen ice
find more resources at oneclass.com
find more resources at oneclass.com
Pluto from New Horizons
• Relief on surface of Pluto
o Mountains = 3500 m high
o Haze layers = backlit by the Sun
o Does have an atmosphere
▪ Chemistry that happens to that atmosphere to produce haze (almost 11
layers)
o GEOLOGY HAPPENING HERE AT – 200 TO – 240OC
▪ METHANE, CARBON MONOXIDE, NITROGEN ARE ALL SOLID
• Craters/Surface Age
o Some areas that have lots of craters that can be up to 4 Ga
o Sputnik Planitia = NO CRATERS
o Old surface (~ 4.5 Ga) to young (10 – 100 Ma) (*)
• Geological Features: Sputnik Planitia
o Nitrogen ice
▪ Enough ice that flows like a slow, viscous liquid
o Probably an impact basin
▪ Filled by ices after it was formed
o Nitrogen ice glaciers that are carrying water ice rocks
o Cellular terrain (FLAT)
▪ Convection cells in nitrogen ice
• Indication of how thick the ice is
• Potentially thicker than ~ 500 m (insulating blanket for the heat
from the interior to come up and cause convection within these
nitrogen ice)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
New horizons: has everything you need to image the object in visible and ir and uv light on the spectrum. Kuiper belt: trans-neptunian orbits (beyond the orbit of neptune, ma(cid:374)y of these o(cid:271)je(cid:272)ts are (cid:448)ery dark = lo(cid:449) al(cid:271)edo, do(cid:374)"t refle(cid:272)t (cid:448)ery (cid:449)ell so hard to pick up. Above but because the ice is so thick, this why we. See the cellular terrain (resurfacing the ice = would explain why it"s so young there: pitted nitrogen ice, sun causing sublimation from ice to gas, use ir to figure out what kind of ice is there. Pluto and charon: interiors: geologically dead, losing heat (because of its size, sources of heat, no solar influence, tidal energy? (liquid ocean from charon maybe early in history, radiogenic. Activity: pluto is large enough to continue producing an ocean, whereas charon is not, probably why it froze and cause the fracturing. Triton: probably came from similar origins as pluto and charon.
