Astronomy Second-Third Test

Question 1

3 planet properties

Answer 1

moons atmosphere type
Mercury: 0 trace terr
venus: 0 very thick terr
earth 1 perfect terr
mars 2 thin terr
jupiter 63+ very thick jovian
saturn 61+ very thick jovian
uranus 27+ very thick jovian
neptune 13+ very thick jovian
(pluto) 3/5 very thick jovian
rings around all four jovians, all on same plane going east around sun.

Question 2

tilts of planets

Answer 2

.1° merc 177° venus 23° earth 25° mars 3° jupiter 27° saturn 98° uranus 30° neptune 120° pluto

Question 3

smaller bodies in solar system

Answer 3

Ganymede is the biggest 5262km, then Titan, 5150km, then mercury, callisto, io, luna. Titan and Ganymede bigger than mercury!

Question 4

Bode’s Law

Answer 4

Not really a law and not really by bode.
Take the sequence 0,3,6,12… add four and divide by ten to get
.4, .7, 1.0, 1.6, 2.8, 5.2, 10.0.
This very nearly matches the distance of each planet from the Sun in AU going out in order.

Question 5

Problems with Bode’s law

Answer 5

at 2.8 there is no planet- asteroid belt instead, where jupiter’s gravity prevented planet formation. Ceres’ discovery in 1801 began to solve this problem.

Neptune does not fit in the pattern, pluto is where it should be. However pluto’s orbit is so elliptical it sometimes is closer than neptune.

Question 6

other thing to do with bode’s law

Answer 6

get AU with bode, period/mass with newton’s kepler’s third.

Most massive moons of saturn also follow it.

Question 7

Mercury facts

Answer 7

38% Earth’s diameter
59d rotational period, orbit 88- 3/2 radio
every two revolutions of sun, hits apogee.
-315°F - 800°F ground temp.
.205 eccentricity
.01 albedo
trace atmosphere, 42% O2 (prolly Co2) 29% sodium, 28%H2
mag field 1% earth’s.

Question 8

Mercury surface

Answer 8

heavily cratered, rocky lava flows, extinct volcanos, bit of water ice.

Question 9

elongation/conjunctions

Answer 9

For a body between an observer and the sun, the body will only get a certain number of degrees away from the sun in the night sky. This is when the planet’s maximum distance from the sun as seen on its orbit’s plane across the sun. East and west greatest elongations are these points, inferior conjunction is when planet is aligned between earth and sun, superior when planet is aligned on other side of sun.

Question 10

Mercury’s greatest elongation

Answer 10

28° as seen from earth, 15°/hr sky movement means less than two hours to see mercury. Mercury is small and faint, with one hour of dusk and any light polution it is very hard to see -fix this.

Question 11

Messenger’s path to mercury

Answer 11

did extremely intricate systems of oribts around earth, venus, and 3 times around mercury before it settled around there.

Question 12

precession of merc’s perihelion

Answer 12

will probably have to draw this, basically the orbit changes direction. early proof for general relativity.

Question 13

mercury false color

Answer 13

yellows are basalts, craters are blue, looks like moon. RGB filters are combined on a computer.

Question 14

Venus properties

Answer 14

82% earth's mass
surface temp 864°F
93x earth's temp
96% CO2, 3.5% nitrogen
no mag field
264 days retrograde rotation...

Question 15

venus surface

Answer 15

sandy and rocky, extinct volcanos and lava fields, everything heavily eroded-all rocks flat. thanks to radar have detailed elevation map of venus. collapses pancake domes. maats mons 26k feet high. aranoids spidery formations.

Question 16

venus atmosphere

Answer 16

a bit transparent to UV, transparent to radio, otherwise opaque. layer of sulfuric acid that rains down but doesn’t get to surface. makes life difficult….

Question 17

how to measure rotation

Answer 17

use radar/radio waves to measure doppler effect. First done in 1961 at the 85’ dish at goldstone. Dish had transmitter to do bouncing. Rotation of side coming at you is blueshifted, away is redshifted.

Question 18

why so slow rotation period

Answer 18

spin-orbit coupled with earth, same side faces us at each closest approach. mascons on venus!

Question 19

why venus so hot

Answer 19

runaway greenhouse effect- heat from sun is trapped. on earth, IR heat radiates back into space. can’t on venus. high temp causes outgassing from atmosphere causes more greenhosue etc etc. appears to be at equilibrium now. start of cycle unknown.

Question 20

venus landers

Answer 20

soviet venera 13 and 14. soft landed on ring. had mass spec, camera, chonometer, color chart, soil drill, hydrometer. spectrometer too.

Question 21

terraforming venus

Answer 21

transform C02 into o2. dump algae bombs on planet.

Question 22

Mars facts

Answer 22

atmosphere 1/200th ours, mostly CO2.
24hrs 39 minutes day. - like us
25° tilt. - like us
-250-60°F night/day.

Question 23

mars atmosphere

Answer 23

quite thin. mostly CO2. Water clouds, winds and sandstorms

Question 24

mars surface

Answer 24

polar ice caps have H20 and CO2 frozen. frosts in floors of craters near poles. sand and rock, iron oxides, ice. evidence of past water flow everywhere, apparently liquid water still might be underground.

Question 25

Olympus mons

Answer 25

extinct mountain volcano, 90k ft tall, 450 miles across. 3x height of everest.

Question 26

Valles Marinaris

Answer 26

gigantic canyon, made from past liquid flow. as long as united states is wide.

Question 27

opposition

Answer 27

close approach of two planets in orbit.

Question 28

holes in mars surface

Answer 28

sometimes sides of extinct lava domes. 275 feet deep. tunnels- lava tube flows. maybe put astronauts in these caves?

Question 29

evidence of past water flows

Answer 29

valles marinaris water flows, “wake islands” in old water channels, fault slip cliffs where water broke through and made a river.

Question 30

current liquid water?

Answer 30

Normally water on mars is either frozen or vapor, not enough atmospheric pressure to have liquid. ice sublimates, but maybe pressure under surface allows for liquid. wet sand seen on wind-shaped cliffs

Question 31

viking mars rover

Answer 31

first landing 1976, two vikings. original landing spot was too bouldery so they changed it mid-flight. landed with retrorockets and parachute. had a telescoping arm to reach for the soil, cleaning arms, cleaning arm whacked other arm. vaporized scooped stuff up.

Question 32

sojourner+pathfinder

Answer 32

1997. rover+lander. with airbags. rover was a foot long.

Question 33

spirit + opportunity

Answer 33

2004. twin rovers detected hematites. landed with parachute, airbags, platform. “blueberries”, sign of standing water previously on mars. martain surface (in one place) very fine packed sand (hard), dust devils.

Question 34

oppy encountered

Answer 34

Cape victoria, old crater with eroded sides and sand dunes in the middle. Side features called duck bay and cape verde.

Question 35

spirit found

Answer 35

on mesa called HOME PLATE. in polar region so during winter hibernated on slope for solar power. was almost lost during a monthlong sandstorm.

Question 36

CURIOSITY

Answer 36

landed 2012. Heatshield->parachute->retrorockets->sky crane dropped it. found some organic molecules.

Question 37

moons of mars.

Answer 37

phobos (28km) and deimos (16km). captured asteroids, not rounded. synchronous rotation.

Question 38

jupiter four moons

Answer 38

Galilean moons, the four biggest. on a plane.

Question 39

Jupiter outer atmosphere.

Answer 39

great red spot been spinning for hunderds of years- no friction below it to slow it down. different colored cloud bands paralell to equator. rotation period 9h50m. 11x diamter of earth, 300x mass. smaller storms caused by atmosphere turbulence, sweeps away ice crystals so you can see below surface.

Question 40

layers going in

Answer 40

water ice->ammonium+ammonium hydrosulfate clouds->gradual transition to liquid (H2)-> liquid metallic hydrogen (H)->rocky core, size of earth.
transitions hard to deescribe, between liquid and gaseous, not discrete phases like on earth.

Question 41

other jup facts

Answer 41

rings are solid particles (methane, water, Co2 ices) orbiting planet, aurorae caused by solar wind+atmosphere+jup’s magnetic field.)

Question 42

MOON SIZES

Answer 42

ganymede, callisto, europa, io SIZES IN ORDER

Question 43

Io

Answer 43

2% bigger than earth’s moon. Extremely volcanis as discovered by Linda Morabito at JPL in 79. Volcanos due to extreme tidal forces from Jupiter’s gravity. No atmosphere so volcanic material flies up, freezes, snows back down.

Question 44

Europa

Answer 44

Like most jovian moons, ice-covered. ice-cover is a good insulator, liquid water possible below surface- LIFE POSSIBLe

Question 45

Saturn facts

Answer 45

Rings made up of many ice chunks, shepard moons keep them around. Saturn tilt 27° means over 30 yr cycle that rings are seen from different angles to earth. has bands etc same as jupiter.

Question 46

Titan

Answer 46

> 4% larger than mercury. Has an atmosphere 3x thicker than Earth’s, made of nitrogen and methane. Lakes and rivers of liquid methane on the surface. Boulders and chunks of methane. very cold though due to extreme distance from sun

Question 47

Enceladus

Answer 47

Moon of saturn. covered with ice, which maintains a record of cratering throughout solar system history. tiger stripes near south pole spew liquid water as geysers- weird! Some kind of internal heating??

Question 48

Uranus

Answer 48

has rings and moons. blue due to methane in atmosphere. white spots turbulence/storms. otherwise same as jupiter…

Question 49

Neptune

Answer 49

bluer than uranus more methane. has a great blue spot. Predicted by perturbations in uranus orbit. Tilted 88°/92°. On side.

Question 50

Triton

Answer 50

Moon of neptune. NOT titan. 80% size of earth’s moon. water ice, dirty water ice. retrograde rotation! WHY! IDK

Question 51

Pluto.

Answer 51

Wrongly predicted 1915, discovered 1930 by Clyde Tombaugh found it.

Question 52

How to discover pluto

Answer 52

Look at negative of star plates. apparent motion of stars, look for different ones. Really used BLINKER PLATE, shows 2 plates flashing make it easier to see differences. 10000s of stars, hard to see/find.

Question 53

Charon

Answer 53

Moon of pluto- discovered from a silver lump in the photos 1978. Now 5 bodies, Nix and Hydro plus P4 and P5.

Question 54

Pluto facts

Answer 54

VERY eccentric orbits compared to rest of solar system. on an incline too…. very cold, this atmosphere. dark and light areas can be mapped. eccentric enough that it crosses neptune’s orbit. terrestrial. Not a former moon of neptune.

Question 55

eris and sedna

Answer 55

way out from pluto. nonsensical eccentric orbits.

Question 56

planetary definition process

Answer 56

Harvard had definitions, E europeans had defintions. waited til last day of planet conference in prague when only E europeans were left- they voted one of theirs.

Question 57

Shitty defition of planet

Answer 57

1. Must orbit sun - exoplanet
2. Must be massive enough to get spherical shape - minor planet
3. Must have cleared its orbital path of debris - dwarf planet

Question 58

Asteroids

Answer 58

Space rocks… asteroid belt. trojans following jupiter and in front of it. Apollo asteroids go from belt to earth around sun. earth people want to be able to divert the, >9000 near earth asteroids, possibly millions more.`

Question 59

Comets

Answer 59

Ice bodies from outside solar system. can have absolutely gratuitous orbits. 1.5yrs to 17k years. Come in from any plane cause their origin is in a spherical shape around solar system.

Question 60

Comet diagram/info

Answer 60

Water sublimates when it gets close to sun. Nucleus of comet (10km) across. Coma of the cost (glowing gas around head) 100,000km across. 2 tails. Ion trail always pointing away from sun, dust trail following orbital path. Often can break up close to sun, can spectrally analyze them!