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AST 1002
Final Exam Review
100
Astronomy
Undergraduate 1
04/26/2011

Additional Astronomy Flashcards

 


 

Cards

Term
AU
Definition
Astronomical Unit - distance from the Earth to Sun.
Term
ly
Definition
Distance light travels in one year.
Term
AU is the distance of what ?
Definition
The distance between Earth and the Sun
Term
ly measures what ?
Definition
Measures the distance light travels in one (1) year.
Term
What particles are found in an atomic nucleus ?
Definition
Protons and Neutrons
Term
Negatively charged protons in the nucleus are called ?
Definition
Electrons
Term
In the North Hemp., stars travel which direction around Polaris ?
Definition
counterclock-wise
Term
The stars rise in the _________ and set in the _________.
Definition
East / West
Term
The sun travels on the ______________.
Definition
ecliptic path
Term
The ecliptic path is tilted ________degrees.
Definition
23.5 degrees
Term
The Sun reaches the greatest distance North of the equator during ____________.
Definition
The summer solstice
Term
The Sun is at the greatest distance from the South of the equator during _________.
Definition
Winter Solstice
Term
When is the summer solstice ?
Definition
about June 21
Term
When is the winter solstice ?
Definition
about December 21st
Term
The vernal and autumnal equinox is when _____________.
Definition
the Sun cross the celestial equator and have equal days and nights.
Term
When are the vernal and autumnal equinox?
Definition
about March 21 and September 21
Term
The change of the seasons are a result of ______________.
Definition
the tilt of the Earth's axis rotation
Term
How long is one (1) lunar cycle ?
Definition
29.5 days
Term
What are the four (4) lunar phases ?
Definition
New Moon
First Quarter
Full Moon
Third Quarter
Term
When the Sun-Earth-Moon are aligned in the Full Moon phase it is called ?
Definition
Lunar eclipse
Term
When the Sun-Moon-Earth are aligned in New Moon phase what is it called ?
Definition
Solar eclipse
Term
Aristotle and Ptolemy believe in which solar system model ?
Definition
geocentric
Term
Copernicus, Kepler and Galileo believed in which solar system model ?
Definition
heliocentric
Term
Describe the heliocentric solar system model.
Definition
The Sun is the center of the universe.
Term
Describe the geocentric solar system model.
Definition
The Earth is the center of the universe.
Term
Kepler's first law states ______________.
Definition
that the planets travel in elliptical orbits around the Sun.
Term
Copernicus believed that planets _____________.
Definition
traveled in circular orbits around the Sun.
Term
Why are Venus and Mercury never seen in the late night sky ?
Definition
because they are closer to the Sun than Earth is.
Term
Newton's Law of Gravity states that ________________.
Definition
every mass is attracted to every other mass in the universe that is proportional to the product of the masses of each object and inversely proportional to the square of the distance between the centers of each object.
Term
What are the seven (7) regions of the EM spectrum longest to shortest wavelength.
Definition
Radio, microwaves, infared, visible, ultraviolet, xrays, gamma rays.
Term
How does a stars color relate to its temperature ?
Definition
Blue colored star is hotter than the red ones.
Term
What is the Large Impact Theory ?
Definition
Mars sized object struck Earth 4.5 billion years ago and caused the moon to form from the ejected materials.
Term
How long ago did the Large Impact Theory happen ?
Definition
4.5 billion years ago.
Term
What are lunar maria ? How are they formed ?
Definition
large dark crater basins on the moon that have been filled in by dark basaltic lava flow over 3 billion years ago.
Term
How are lunar maria and highlands different ?
Definition
Term
Name the eight (8) major planets in order from closest to the Sun outward ?
Definition
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
Term
Which planets are terrestial planets (inner) ?
Definition
Mercury, Venus, Earth, and Mars.
Term
Which planets are outer planets ?
Definition
Jupiter, Saturn, Uranus, and Neptune.
Term
What is the Solar Nebula Theory ?
Definition
A nebula contracted due to gravity, rotated and flattened to cause the Sun and the planets.
Term
How does the Solar Nebula Theory explain some features in the solar system ?
Definition
Term
Describe the surface of Mercury.
Definition
heavily cratered like the far side of the moon and has scarps (long cliffs from when the planet cooled and shrank)
Term
Describe the surface of Venus.
Definition
volcanic highlands and lowlands of cooled lava flows.
Term
Describe the surface of Mars.
Definition
reddish surface (rusty rock), has largest volcano (Olympus Mons)in the solar system, and a large deep crack as long as the U.S.
Term
Why does Earth have so few craters ?
Definition
because of the weathering process the craters wear down over time. Also the Earth's atmosphere cause metorites to burn up before hitting the surface.
Term
Which terrestial planet has the hottest surface ?
Definition
Venus because of the runaway greenhouse effect.
Term
Which terrestial planet is the smallest ?
Definition
Mercury
Term
How many moons does each terrestial planet have ?
Definition
Mercury and Venus have zero (0). Earth has one (1), and Mars has two (2).
Term
Which terrestrial planets have evidence of past or present volcanic activity.
Definition
Venus, Earth and Mars.
Term
Which of the terrestial planets have an atmosphere ? What are the main components ?
Definition
All except Mercury have atmospheres. Venus and Mars is mostly carbon dioxide gas and Earth is mostly nitrogen gas.
Term
Why is Mars "reddish" ?
Definition
because of the rusty rocks from iron oxides.
Term
What are Mars' polar ice caps made up of ?
Definition
Water ice and carbon dioxide ice (dry ice).
Term
What are two pieces of evidence that Mars used to have running water.
Definition
Erosion and deposition features (river channels and layered deposits commonly in lakes)
Term
What is special about Jupiter's moon Io ?
Definition
it has several active sulfuric volcanoes erupting on its surface.
Term
What is special about Saturn's moon Titan ?
Definition
it has an atmosphere denser than Earth's and mostly the same composition.
Term
What is the name of the probe that landed on Titan ?
Definition
the Huygens probe landed on Titan during the Cassini mission.
Term
What was discovered on Titan by the Huygens probe ?
Definition
Large dunes and lakes and rivers of methane.
Term
How is Pluto's surface different from other planets ?
Definition
1. Its highly eccentric orbit (not circular)
2. Sometimes found closer to the Sun than Neptune.
3. Orbit is tilted 17 degrees to the elliptical plane.
4. It is mostly rock and ice.
Term
Why was Pluto called a "dwarf planet" in 2006 ?
Definition
Because of the discovery of Eris and that it does not sweep its orbit clear of other objects.
Term
Which outer planets have rings ?
Definition
All of them do.
Term
Which outer planet has a rotational axis at 90 degrees ?
Definition
Uranus
Term
Which planet has a bluish tint and Why ?
Definition
Uranus and Neptune cuz of the presence of methane gas which absorbs the red and reflect blue light.
Term
Why do Saturn's rings look larger than other planets ?
Definition
Because of the large amount of water ice in the rings, it reflects the sunlight.
Term
What is up with Jupiters "Great Red Spot" ?
Definition
it is large long lived circular storm.
Term
What is the Roche-Limit and what causes it ?
Definition
It is the distance from an astronomical body at which its gravitational force can pull apart another. It is due to the gravitational tidal forces.
Term
Do Saturn's rings lie inside or outside the Roche-Limit ?
Definition
Inside
Term
Why are the outer planets so large ?
Definition
Their distance from the Sun allowed the light gases to coalesce into large planets.
Term
Which outer planet is closest to the asteroid belt ?
Definition
Jupiter
Term
What are the six layers of the Sun ?
Definition
Core, Radiative Zone, Convective Zone, Photosphere, Chromosphere, Corono
Term
Which layer of the Sun is the hottest ?
Definition
the core
Term
Which layer of the Sun radiates mostly in the visible range of the EM spectrum ?
Definition
Photosphere
Term
The Sun is mostly _____________ which fuses into _______________.
Definition
Hydrogen (H) element / helium (He)
Term
When (H) fuses into (He) in the core is produces heat and energy due to ___________.
Definition
the mass of the helium product of nuclear fusion is less than the mass of the original H atoms and the excess initial mass is converted into energy E=mc2
Term
What is the state of Hydrostatic Equilibirum ?
Definition
So that the inward pull of gravity is balanced by the outward push of thermal pressure of the Sun.
Term
How long is a sunspot cycle ?
Definition
11 years
Term
What causes the sunspot cycle ?
Definition
The differential rotation rate of the Sun.
Term
What can happen during a sunspot cycle ?
Definition
During an active cycle the rate of solar winds towards Earth are increased which cause power outages, damage to Earth's satellites, and increased auroras.
Term
What is a pc
Definition
one parsec
Term
How many ly is one pc ?
Definition
3.26 ly
Term
What are the stages of evolution in order ?
Definition
Term
How long will the Sun stay in the main sequence ?
Definition
11 years
Term
Why will the Sun leave the main sequence ?
Definition
Hydrogen is depleted in its core.
Term
What are the other stages of evolution like ?
Definition
Term
How do the stages of low mass stars differ from those of high mass stars ?
Definition
Term
How are the lifetimes of low mass stars different from those of high mass stars ?
Definition
Term
What is the temperature, luminosity, and colors of stars while on the main sequence ?
Definition
Term
What is a neutron star ?
Definition
Term
What is a black hole ?
Definition
Objects with such a great gravitational force that nothing can espcape its radius.
Term
Which types of stars end up as neutron stars or black holes ?
Definition
Term
What is the layered structure of a red giant ?
Definition
Layers of nuclear fusion build up with the heaviest elements being fused closest to the center.
Term
How does fusing iron in the core lead to a supernova explosion in high mass stars ?
Definition
Term
Why is a past explosion important to us on Earth ?
Definition
Term
After a supernova explosion what does the remnant core become ?
Definition
Term
How are the remnant of the core after a supernova explosion characterized ?
Definition
Term
How does a neutron star differ from a white dwarf or black hole ?
Definition
Term
What is the escape velocity of a black hole ? How can we detect them ?
Definition
Not even light can escape the radius. Evidence is from binary stars that pull matter from neighboring stars, which causes Xrays and other radiation, which we CAN detect.
Term
What is the Milky Way galaxy and what shape is it ?
Definition
Our Milky Way galaxy is spiral.
Term
How many stars are in our galaxy ? And where is the Sun located ?
Definition
100 billion stars, and the Sun is located half way out.
Term
What are the three (3) main types of galaxies ?
Definition
Irregular, spiral, and elliptical
Term
How does Hubble's Law support the Big Bang Theory ?
Definition
Term
What is the current estimated age of our universe ?
Definition
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