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Astronomy Final
Ast.
41
Astronomy
Undergraduate 1
05/09/2011

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Cards

Term
Why is the moon's sky always dark?
Definition
Because it does not have an atmosphere to scatter the light.
Term
Name the planets in order of increasing distance from the sun?
Definition
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
Term
Describe Comets
Definition
-Dirty Snowballs (Avg Size- 5-10 km)
-Has tails (Ion and Dust)that always point away from the Sun
-Leaves behind debris that cause a meteor shower.
Term
Describe Asteroids
Definition
-Rock / Potato shaped / 50 km to 100 km / craters
- Sits in between Mars and Jupiter (Terrestrial and Jovian planets)
Term
What is zodiacal light?
Definition
Dust in the plane of the solar system that sunlight shines off of.
Term
What is zodiacal light?
Definition
Dust in the plane of the solar system that sunlight shines off of.
Term
What is a scarp?
Definition
A long cliff. Discontinuity on the Moon.
Term
What are there almost no maria on far side of the moon?
Definition
The crust on the far side is thicker. When objects hit it the crust did not crack.
Term
Why is the density of Mercury so high?
Definition
It has the highest % of iron core in solar system.
Theory is that something big hit Mercury and knocked off the exterior it had.
Term
How does the temperature on the night side of Venus compare to that on the day side?
Definition
Maintains a similar temperature throughout day and night time.
Term
What is meant by 3-2 spin orbital coupling?
Definition
Rotates 3 times on its axis every 2 orbits.
Term
How were the Moon and the maria on the Moon formed?
Definition
-Got hit by debris and made a hole in surface.
-Lava leaked out and filled the holes and formed the Maria.
Term
Where is the asteroid belt? Kuiper Belt? Oort Cloud?
Definition
Asteroid Belt - Between Mars and Jupiter
Kuiper Belt - Sits outside the orbit of Neptune from 30 to 50 AU.
Oort Cloud - Sits beyond the Kuiper Belt.
Term
Largest and Most Massive Planet?
Definition
Jupiter
Term
What is the smallest planet in the solar system?
Definition
Mercury
Term
Radiant
Definition
The places among the stars from which the meteors appear to come.
Term
What is the source of meteor showers?
Definition
The earths orbit passing through the debris of a passing comet.
Term
How big are the fragments in a meteor shower?
Definition
About the size of a grain of sand.
Term
What satellite has an atmosphere? What is its composition?
Definition
Titan - 95% Nitrogen with rest being predominately methane.
Term
Which is the most volcanically active object in the solar system?
Definition
Io
Term
What is the great red spot?
Definition
A persistent storm on Jupiter's surface
Term
Which Jovian planets have rings?
Definition
All Jovian planets have rings.
Term
Which planets have magnetic fields?
Definition
Earth, Jupiter, Saturn, Uranus, Neptune
Term
What the two (3?) most likely places for life (probably primitive) to exist in the solar system?
Definition
Mars and Europa (Maybe Enceladus)
Term
Why do we have seasons?
Definition
The earth is titled from the perpendicular towards the plane of orbit and it maintains and orientation.
Term
Opposition
Definition
Opposite in the sky from the Sun
Term
How have we discovered planets that orbit other stars?
Definition
We discover other planets orbiting around other stars by seeing transits of these planets across the star.
We can use the doppler effect to view the wobble of the planet.
Term
What does the density of a satellite tell you about its composition?
Definition
Density can tell you if its mostly rocky or mostly icy.
Term
What are shepherd satellites?
Definition
Keep particles contained within their orbits.
Reason the F ring exists on Saturn.
Term
Describe the make-up of Saturn's rings. (size and composition)
Definition
-Composed of Water Ice
-Average size of particles is the size of a snowball.
Term
How were the rotation rates of Mercury and Venus determined?
Definition
Determining rotation rates is dependent on radar ranging (Red shift / Blue Shift)
Term
Over the course of one night, does Orion change positions?
Definition
Orion moved East to West across the sky overnight because the Earth is rotating towards the East on its axis.
Term
Over the course of several weeks, why when observed at the same time of night was Orion in a different position in the sky?
Definition
Because the Earth orbits the sun and the stars in the night sky slowly change.
Term
Describe the Atmosphere of Venus, Mars, and Earth.
Definition
Venus - CO2
Mars - CO2 (much thinner)
Earth - Nitrogen, Oxygen
Term
If Venus, Earth, and Mars all started out with similar atmospheres, why are they now so different?
Definition
- Venus became so hot because it didn't rain (had a runaway greenhouse effect)
- On Mars the volcanic activity stopped; stopped source of CO2.
+Rained all the CO2 out of the atmosphere.
Term
What is the Roche Limit?
Definition
The distance where a particles tidal force is just as strong as the gravitational force between it.
- Particle pulls apart and forms a ring around the planet.
Term
How does a dwarf planet differ from a planet?
Definition
A dwarf planet is an object orbiting the Sun with enough mass to gravitationally pull itself into a spherical shape, yet not enough gravity to clear out surrounding planetesimals.
Term
How does the green house effect impact the temperature on the surface of Earth?
Definition
It maintains the temperature at 57 degrees. It does this by trapping the infrared radiation within the atmosphere.
Term
Seven Satellites and their Planets
Definition
Moon - Earth
Io - Jupiter
Europa - Jupiter
Ganymede - Jupiter
Callisto - Jupiter
Titan - Saturn
Triton - Neptune
Term
Why does Saturn's atmosphere have a smaller % of Helium than Jupiter, Uranus or Neptune?
Definition
Because Saturn is smaller it cooled quicker. Through this cooling a process was triggered that induced liquid helium rain. Helium is not present in Saturn's upper atmosphere because it dropped down to the lower layers of the planet.
Term
Composition of Jovian Planets
Definition
Outer layers of the Jovians are composed of - hydrogen and helium.
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