Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
62 Cards in this Set
- Front
- Back
What is the meaning of albedo? |
The higher the albedo, the more light the surface reflects, and the less it absorbs. |
|
Which planet has the most substantial atmosphere? |
Venus |
|
Which planet has the least substantial atmosphere? |
Mercury |
|
What are greenhouse gases? |
gases that absorb infrared light |
|
How does the greenhouse gases effect work? |
GG transmit visible light, allowing it to heat the surface, but then absorb infrared light from Earth, trapping the heat near the surface.
|
|
The proper order of the layers of the atmosphere from lowest altitude to highest is |
troposphere, stratosphere, thermosphere, exosphere. |
|
Which planet has a stratosphere? |
Earth |
|
The sky is blue because? |
molecules scatter the blue light more effectively than the red light. |
|
Convection occurs in the troposphere but not in the stratosphere because |
lower altitudes of the troposphere are warmer than higher altitudes, unlike the stratosphere. |
|
What is the difference in weather and climate? |
Weather refers to short-term variations in conditions, and climate refers to long-term variations in conditions. |
|
Why doesn't Venus have seasons like Earth and Mars? |
Its rotation axis is not tilted. |
|
From where did the molecular oxygen in Earth's atmosphere originate? |
photosynthesis from single-celled organisms |
|
Why do jovian planets bulge around the equator? |
Their rapid rotation flings the mass near the equator outward.
|
|
How do astronomers think Jupiter generates its internal heat? |
contracting, changing gravitational potential energy into thermal energy. |
|
Why is Jupiter denser than Saturn? |
The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn. |
|
Why is Neptune denser than Saturn? |
It has a different composition than Saturn, including a higher proportion of hydrogen compounds and rocks. |
|
Why do the jovian planets interior differ? |
Accretion took longer further from the Sun, so the more distant planets formed their cores later and captured less gas from the solar nebula than the closer jovian planets. |
|
Why does Jupiter have several distinct cloud layers? |
Different layers represent clouds made of gases that condense at different temperatures, |
|
The four Galilean moons around Jupiter are |
a mixture of rock and ice, with the ice fraction increasing with the distance from Jupiter. |
|
The fact that most moons always show the same face to their planet is |
a natural consequence of tidal forces acting on the moons. |
|
What causes synchronous rotation? |
A massive planet exerts a tidal force on a moon that causes the moon to align itself such that its tidal bulges always point toward and away from the planet. |
|
What is the most important reason why an icy moon is more likely to be geologically active than a rocky moon of the same size? |
Ice has a lower melting point than rock. |
|
Why are Saturn's rings so thin?> |
Any particle in the ring with an orbital tilt would collide with other ring particles, flattening its orbit. |
|
Planetary rings are |
all of the above |
|
Which planet can't be seen with the naked eye? |
Neptune |
|
Which planets location was predicted using calculations of orbital motions? |
Neptune |
|
True of False: Comets are balls of ice and dust. |
True |
|
A rocky leftover planetesimal orbiting the Sun is |
an asteroid |
|
Why do asteroids and comets differ in composition? |
Asteroids formed inside the frost line, and comets formed outside the frost line. |
|
Ceres, the largest asteroid, compares how in size to other solar system worlds? |
It is about half the size of Pluto. |
|
The combined mass of all the asteroids in the asteroid belt is |
less than that of any terrestrial planet. |
|
The large gaps in the asteroid belt are caused by |
orbital resonances with Jupiter. |
|
Why isn't there a planet where the asteroid belt is located? |
Gravitational tugs from Jupiter prevented material from collecting together to form a planet. |
|
What is a meteorite? |
a fragment of an asteroid from the solar system that has fallen to Earth's surface. |
|
Meteorites can come from |
comets, cores of asteroids, the Moon, and Mars. |
|
When do comets begin to form a tail? |
In Jupiter's orbit |
|
The dinosaurs died off largely because |
the dust injected into the stratosphere from the impact absorbed visible light from the Sun, causing global temperatures to plummet. |
|
When was Pluto discovered? |
about 80 years ago |
|
Why aren't small asteroids circular in shape? |
The strength of gravity on small asteroids is less than the strength of the rock. |
|
Approximately how many other planetary systems have been discovered to date? |
a thousand |
|
The Doppler technique provides a measure of a planet's |
minimum mass, orbital eccentricity, orbital radius |
|
A planet's density can be measured by combining |
Doppler and transit observations |
|
The transit method of planet detection works best for |
big planets in edge-on orbits around smaller stars |
|
Which planet occasionally transits across the face of the Sun? |
Mercury. |
|
Which planet search technique is currently best suited to finding Earth-like planets? |
transit |
|
The repeating pattern of the stellar motion of a detected planet via Doppler tells us |
the orbital period of the planet |
|
The depth of the dip in a star's brightness due to the transit of a planet depends most directly on |
the planet's size. |
|
How do we think the "hot Jupiters" around other stars were formed? |
Gas giants beyond the frost line and then migrated inwards |
|
What is a consequence of the discovery of hot Jupiters for the nebular theory of solar system formation? |
Modified to allow for planets to migrate inwards or outwards due to gravitational interactions. |
|
The Doppler technique only provides a measure of the minimum mass of a planet because |
only the motion of star toward the observer is measured, not the full motion. |
|
What is the Sun made of? |
70% hydrogen, 28% helium, 2% other elements |
|
The phase of matter the Sun is in |
plasma |
|
From the center outward, list the layers of the Sun in order? |
core, radiation zone, convection zone, photosphere, chromosphere, corona |
|
Why do sunspots appear dark in pictures of the Sun? |
They actually are fairly bright but appear dark against the even brighter background of the Sun. |
|
How does the Sun generate energy today? |
nuclear fusion |
|
How much mass does the Sun lose through nuclear fusion per second? |
4 million tons |
|
What are coronal holes? |
areas of the corona where magnetic field lines project into space allowing charged particles to escape the Sun and become part of the solar wind. |
|
What processes are involved in the sunspot cycle? |
the winding of magnetic field lines due to differential rotation |
|
What is the major drawback of the gravitational contraction theory? |
It predicted that the Sun could last only about 25 million years, which is far less than the age of the Earth. |
|
What does the Sun being in gravitational equilibrium mean? |
There is a balance within the Sun between the outward push of pressure and the inward pull of gravity. |
|
What is the average temperature of the surface of the Sun? |
6,000 Kelvin |
|
What happens to energy in the convection zone of the Sun? |
It is transported outward by the rising of hot plasma and the sinking of cooler plasma. |