SOLAR SYSTEM EXAM 3 – Flashcards
Unlock all answers in this set
Unlock answersquestion
How can the eight major planets of our solar system can be classified on the basis of their properties and orbits?
answer
They divide naturally into two main groups.
question
Where in the solar system would you find Kuiper belt objects?
answer
beyond the orbit of Neptune, extending perhaps as far as 500 AU from the Sun
question
Which components of the present solar system have probably remained essentially unchanged since the solar system was formed and can therefore provide valuable clues to the manner of this formation?
answer
comets, asteroids, and meteoritic material
question
Why do astronomers no longer consider Pluto to be a planet?
answer
It is a member of a system of small objects, most of which are too small to be planets and show different orbits than the eight main planets.
question
An object less than a thousand kilometers across, composed of rock and iron and orbiting closer to the Sun than the planet Jupiter, would be called
answer
an asteroid.
question
There are no impact craters on the surface of Jupiter because...
answer
its surface is really the top of a very deep gaseous atmosphere.
question
Our planetary system is believed to have originated in a disk of gas and dust that surrounded the Sun shortly after the Sun formed. Such disks around young stars are
answer
an observational fact, having been observed around other stars in our Galaxy.
question
What are the most abundant elements in the solar system?
answer
hydrogen and helium, as shown by the great mass of the giant planets
question
The early universe appears to have contained only light elements, predominantly hydrogen and helium, and yet we now see significant amounts of heavier elements in stars and planets and our own bodies. Where did these heavy elements originate?
answer
in nuclear fusion in the deep interiors of stars and in violent explosions of massive stars (supernovae)
question
The ages of lunar rocks, brought back to Earth by astronauts and robotic spacecraft, have been determined by measuring the
answer
relative concentrations of radioactive elements.
question
What process heated the early solar nebula as it slowly condensed toward a central protosun?
answer
collisions of particles as they fell toward the center of the nebula due to gravity, thus converting kinetic energy into heat
question
What is the fundamental law of physics that allowed the planets to form, rather than having all of the material simply fall into the Sun?
answer
conservation of angular momentum
question
In our solar system, the inner planets are mostly rock and iron and the outer planets are mostly lighter material, such as hydrogen and ices. Why did the solar system form this way?
answer
The inner solar system was warm enough for the lighter material to vaporize (or never solidify), leaving rock and iron to form the inner planets.
question
What is the process by which the terrestrial planets are believed to have formed?
answer
accretion, in which dust particles stick together to form asteroid-like objects and then collide to eventually form the planets
question
What is the process by which the Jovian planets are believed to have formed?
answer
the accretion of dust and ice particles to form a planetary core, which then captured hydrogen and helium to form the planets that we see today
question
A gas giant planet has been found in orbit around the star HD 209458. How have astronomers been able to study the atmosphere of this planet?
answer
The planet passes in front of the star as seen from the Earth, and its atmosphere absorbs some of the star's light at wavelengths characteristic of hydrogen and other elements in the planet's atmosphere.
question
Many of the extrasolar planets that we have found have masses similar to or even greater than Jupiter, and yet they are orbiting very close to their stars—some well within Mercury's orbital distance from the Sun. Nothing like this is seen in our solar system. How did these massive extrasolar planets come to be where we find them?
answer
They are gas giants that formed much farther out in the protoplanetary nebula by core accretion, like our Jovian planets, and then they migrated inward to where we see them now.
question
What are some properties of the large planets?
answer
further from sun, have rings, tend to be gaseous
question
What are some properties of the small planets?
answer
closer to the sun, tend to be rocky
question
What are some properties of the sun?
answer
at "center", way larger than everything else
question
Do all planets orbit in the same direction?
answer
yes
question
Which planets do not rotate on their axis in the same direction as the other planets?
answer
venus and uranus (and the sun)
question
What are some properties of the terrestrial planets?
answer
rockey, inner solar system, slow rotation, few or no moons
question
What are some properties of the jovian planets?
answer
gaseous, outer solar system, rapid rotation, rings, and many moons
question
What are the properties of Mercury?
answer
looks a lot like moon (dry and has craters), terrstrial, very close to the sun so hard to make good observation, orbits the fastest
question
What are the properties of Venus?
answer
Similar to earth in size and mass, has clouds, very hot and high pressure, run away green house effect, has the highest average surface tempature (greenhouse effect)
question
What are the properties of the earth?
answer
only terrestrial planet to have a moon, has the highest density
question
What are the properties of mars?
answer
one day is roughly 24 hours, their tilt on axis is almost the same as ours (seasons same)
question
What are the properties of jupiter?
answer
gaseous, continuos storm, has the highest mass, most gravitational force
question
What are the properties of saturn?
answer
rings, less dense then water
question
What are the properties of uranus?
answer
tipped on it's side
question
What are the properties of Neptune?
answer
Storm, "mini jupiter"
question
What is a planet?
answer
"a planet is a body that orbits the sun, is large enough (has enough mass) to be round, and has 'cleared the neighborhood' of smaller objects"
question
What is a dwarf planet?
answer
is a planet that orbits the sun and has enough mass to be round, but doesn't clear the neighborhood of smaller objects
question
What is an asteroid?
answer
rocky objects which orbit between mars and jupiter,
question
What are comets?
answer
come from beyond the orbit of neptune and are chunks of very dirty ice
question
Kuiper Belt
answer
Reigon that extends from around Neptune to about 500 AU from sun, some comets come from here, icy and rocky bodies, more massive than asteroid belt
question
Oort cloud
answer
proposed massive sphere of cometary material from 50,000 to 100,000 AU from sun, left over material from formation of solar system, source of unbound comets
question
How many dwarf planets are their in our solar system?
answer
5 that orbit our sun
question
Which planet has the longest day?
answer
Venus (243 earth days) to rotate on axis
question
Where did the elements come from?
answer
after the big band, only the lightest elements emerged (primarily hydrogen and helium), the first stars were primarily made of hydrogen with a little helium, the first stars processed the hydrogen and helium to make the heavier elements
question
What are giant molecular clouds?
answer
cold, massive clouds of gas and a little bit of dust. 71% hydrogen 27%helium and 2% everything else, multiple stars can form one cloud
question
what is a protostar?
answer
the greatest concentration of matter at the center. as materials fall inward it gains speed and collides with other materials and heats up. the whole nebula heats up (kelvin and helmholtz contraction)
question
Roatation
answer
the nebula starts with some rotation, was the material collapses inward, the nebula rotates faster
question
L=MVrotR conversation of angular momentum
answer
L=angular momentum (basically stays the same) M=mass (doesnt change) Vrot=rotational velocity (increases) R=distance from center
question
what is protoplanetarydisk?
answer
when the nebula flattens out, it's in this disk that the planets form
question
What is the result of contraction and rotation?
answer
a flat rapidly rotating disk forms, the matter concentrated at the centers becomes the protosun
question
as the protosun was growing, what parts of the solar nebula were warmer while what parts are colder?
answer
the inner parts are warmer, the outer parts are colder
question
what happened to the inner regions during planet formation?
answer
water were vaporized and other gasses were pushed away and only the heavier elements were left, terrestrial planets formed from the remaining rocky material
question
What is terrestrial planet formation?
answer
Ionized atoms stick by sharing electrons building to dust grains, dust grains and pebbles collide sticking together, accumulate into larger planetsimals
question
What is differentiation?
answer
Gravity tends to drag heavier objects down...planets differentiate
question
What is core accreation?
answer
Cored build up in the same way as terrestrial planets, thanks to colder temps gas was moving slowly and was easily captured by the massive cores Uranus and Neptune probably formed closer to the sun and got flung out
question
Disk instability
answer
Instability in the disk leads to clumps, gravitational collapse allowed planets to form,do not form from rocky cores
question
Radioactive unstable nuclei
answer
Too many protons or neutrons
question
Radioactive decay
answer
Change from one element to another
question
Radioactive dating
answer
Each radioactive nucleus decays at it's own rate
question
Astrometric method
answer
Precise measurements of a stars position in the sky relative to other stars
question
Radial velocity method
answer
also called Doppler shift method, spectrum shifts blue to red and red to blue, yields planets orbital periods, mass and distance from star
question
How do we detect extrasolar planets
answer
Look for wobbles in stars
question
Transit method
answer
Planet orbits in front of star then brightness of star goes down
question
Field reversal
answer
There is evidence that our magnetic field flips from time to time
question
Solar wind
answer
The sun emits charged particles (mostly protons and electrons) called solar windo
question
Rifts
answer
Where crust is breaking apart
question
Subduction
answer
One crust may slip beneath another
question
Which waves cannot make it through liquid P waves or S waves
answer
S waves
question
Seismic waves
answer
Transverse
question
P waves
answer
Longitudinal
question
Earths structure
answer
-crust (least dense, mainly silicates) -mantle (mainly iron-magnesium, slow motion like wax) -liquid core (dense liquid material, mixture of iron, nickel and perhaps sulfur, all melted) -solid inner core (solid iron and nickel, the pressure is so high it makes it solid)
question
The observation that first suggested to geologists that the Earth's core may be molten was that
answer
P waves from an earthquake could be observed on the diametrically opposite side of the Earth from the earthquake, but S waves could not.
question
The reason the Earth has a core of almost pure iron is that
answer
iron is the most abundant heavy element, and it sank while the Earth was molten, by differentiation.
question
The material in the innermost core of the Earth is
answer
hot and solid.
question
The majority of earthquakes occur
answer
at the boundaries of tectonic plates.
question
The magnetosphere is
answer
a cavity within the high-speed solar wind, caused by the Earth's magnetic field.
question
What is the long-term behavior (over millions of years) of the Earth's magnetic field?
answer
The field is normally relatively stable, but the north and south magnetic poles reverse every 300,000 years or so (the north pole becomes a south pole, and vice versa).
question
What is the primary function of a greenhouse gas?
answer
It absorbs infrared radiation emitted by the ground.
question
How many different layers are there in the Earth's atmosphere?
answer
4
question
What are the four layers of the Earth's atmosphere?
answer
1.) Troposphere 2.) Stratosphere 3.) Mesosphere 4.) thermosphere/lonosphere
question
What happens in the troposphere?
answer
sunlight heats earth's surface, causes convection (warm on bottom, cold on top), contains half of the earth's atmosphere, weather occurs in this layer
question
What happens in the stratosphere?
answer
ozone absorbs harmful rays from the sun and UV here and heats up, temperature increases with height, very stable
question
What happens in the mesosphere?
answer
temperature decreases with height, meteors and rock fragments burn up
question
What happens in the thermosphere / lonosphere?
answer
layer with auroras, oxygen and nitrogen atoms absorb, short UV radiation
question
What is half life?
answer
time in which one-half of the nuclei decays, comparing the ratio of elements determines the age
question
Gravitational lensing method
answer
planet passes in front of different star (a star thats behind it), gravitational lensing makes background star look brighter, very rare method
question
What happens as you go from the outter layers of the earth to the inner?
answer
the pressure and temperature increase
question
What is the difference between small and large bodies when it comes to internal heating?
answer
smaller bodies radiate heat quicker, larger bodies should have hot interiors radioactive decay radiates heat
question
Do geographic poles and magnetic poles line up?
answer
No, a geographic north pole is a magnetic south pole and geographic south pole is magnetic north pole
question
What can generate magnetic fields?
answer
electric currents
question
For planets, where is the electric current generated from?
answer
molten outter core in rotation, need a charged material (hot liquid) and needs to be in rotation
question
is the magnetic field static?
answer
No, it is moving all the time and the pole location is changing, north and south poles move independently
question
What is field reversal?
answer
there is evidence that our magnetic field flips from time to time, not clear why it does
question
What is the aurora?
answer
particle overload, a leak through the magnetic field, an interaction with upper atmosphere, when charged particle collide with atoms, northern lights come from here as a result of light being emited
question
What is the internal structure of the earth?
answer
low density crust, crust mantle, liquid outer core (process of differentiation), solid inner core
question
Earths atmosphere
answer
78% N, 21% O, 0.03% Co2, and 0-2% H2O atmosphere shields us from harmful UV radiation help keeps surface warm and spreads heat around gases mostly released through volcanic activity
question
What is the coriolis effect?
answer
on a non-rotating body (object), objects travel in a straight line the earth rotates causing the path of the object to change causes rotation seen in weather systems
question
Greenhouse effect
answer
greenhouse gases (CO2 and H2O) are transparent to visible light, but not to infrared light
question
What does a lot of craters on the moons surface mean?
answer
means the surface is old and has no weathering
question
Does the moon have plate tectonics?
answer
no, or no magnetic field, or no atmosphere has cooler interior
question
What is maria?
answer
remains of huge lava flows, less craters than highlands, is younger, circular in shape (implies large impacts), explains mountains: materials being thrust up from the impact
question
What are lunar highlands?
answer
older, light-colored terrain, far side of the moon is predominately lunar highlands, presume crust is thicker
question
maira vs highlands
answer
maria made of basalt and rich in iron, magnesium, and titanium highlands are rich in calcium and aluminum silicates highland material is generally less dense and older
question
Lunar structure
answer
Magnetometers: no magnetic field seismometers: found moonquakes, but way more earthquakes per year Crust: varies in structure Mantle: too cold and rigid Small molten core containing little iron *compared to earth
question
Lunar rocks
answer
all lunar rocks are igneous rocks (were molten at one time), similar to terrestrial volcanic rocks, are totally dry
question
What is the primary reason for tides?
answer
the moon, but the sun also plays a roll
question
What are spring tides?
answer
when the moon and sun line up their tidal forces line up giving a larger shift in the water level moon is in new or full phase
question
What are neap tides?
answer
when the sun and moon are at right angels the tidal forces partially cancel each other out yielding smaller tidal shifts
question
What is tidal recession?
answer
our moon has even a long term effect on our earth and itself, the earths rotation is faster than the moons orbit around the earth
question
What is synchronous rotation?
answer
the earth exerts tidal forces on the moon, the moon would buldge towards earth due to tidal forces (when moon was molten rock), earths gravitational pull would try and force an alignment, slowing down the moons rotation, moon cooled and locked in this rotation rate and shape
question
What is the fission theory?
answer
spin of earth threw off material from earth onto the moon, can't explain the differing properties of the rocks (missing some elements)
question
What is the capture theory?
answer
the moon was captured by earth's gravity, this is very unlikely
question
What is the co creation theory?
answer
the moon formed debris, similar to the planets. but why only around the earth did a moon form?
question
What is the collisional ejection theory?
answer
collision of large body with young earth > ejected debris from the collision forms the moon > moons interior is molten > moon's surface cools and crust forms: smaller impacts create craters > large impacts create basins > basins flood with lava to form maria
