Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/135

Click to flip

135 Cards in this Set

  • Front
  • Back
What is meant by a geocentric universe?
One where the Earth is the center.
List the 5 basic astronomical objects in the universe:
1. star
2. planet
3. moon(satellite)
4. asteroid
5. comet
What is the term given to a large, glowing ball of gas that generates heat and light through nuclear fusion in its core?
A Star
What is the term given to a moderately large object that orbits a star and shine primarily by reflecting light from its star?
A Planet
List the 3 characteristics that are now required by the IAU to be considered a planet:
1. orbits a star
2. large enough for its own gravity to make round
3. has cleared most other objects from its orbital path
T or F
Based on the IAU's new definition of a planet, does Pluto still qualify? Why?
No, because it hasn't cleared its orbital path
According to the IAU, what is Pluto now considered?
Dwarf planet
What is the term given to an object that orbits a planet?
A moon or satellite
What is the term given to a relatively small and rocky object that orbits a star?
Asteroid
According to the IAU, asteroids are officially considered part of a category known as what?
Small solar system bodies
What is the term given to a relatively small and ice-rich object that orbits a star?
A comet
According to the IAU, comets are part of what category?
Small solar system bodies
Name the 7 collections of astronomical objects:
1. solary system
2. star system
3. galaxy
4. cluster
5. supercluster
6. universe
7. obervable universe
What is the term given to the Sun and all the material that orbits it, including the planets, dwarf planets and small solar system bodies?
Solar system
T or F
Although the term "solar system" technically refers only to our own star sysem, it is not applied to other star systems.
False,
The term is often used with other star systems.
What is the term given to a star and any planets and other materials that orbit it?
Star system
T or F
Roughly half of all star systems contain 2 or more stars.
True
What is the term given to a great island of stars in space, containing from a few hundred million to a trillion or more stars, all held together by gravity and orbiting a common center?
Galaxy
What is the term given to a collection of galaxies bound to gether by gravity?
Cluster or group of galaxies
What are small collections of galaxies called?
Groups
What are large collections of galaxies called?
Clusters
What is the term for a gigantic region of space where many individual galaxies and many groups and clusters of galaxies are packed more closely together than elsewhere in the universe?
Supercluster
What is the term give to the sum total of all matter and energy-that is all galaxies and everything between them?
Universe
What is the other term given to the Universe?
Cosmos
What is the term given to the portion of the entire un iverse that can be seen from Earth, at least in principle
Observable Universe
What is the term that is the average distance between Earth and the Sun which is @ 150 million kilometers
Astronomical Unit (AU)
What is the length of the semimajor axis of Earth's orbit?
1 AU
What is the term for the distance that light can travel in one year?
light year
What is the distance of 1 light year in kilometers?
9.46 trillion kilometers
What is the term given to the spinning of an object around its axis?
rotation
How often does the Earth rotate around its axis?
once each day
What is the term for the orbital motion of one object around another?
Orbit
What is the other term used instead of orbit?
Revolution
How often does the Earth orbit the Sun?
Once a year
What is the term for the increase in the aveerage distance between galaxies as time progresses?
Expansion of the Universe
What is the easiest way to catalgue in your brain the measurement of 1 lightyear?
10 trillion kilometers
How fast does light travel?
300,000 km/s
or
300,000 kilometers per second
or
186,000 miles per second
Who coined the phrase "star stuff"?
Carl Sagan
What is "star stuff"
we are all part of star stuff, that is to say that star stuff is made of material that was manufactured in stars from the simple elements born in the Big Bang
How long ago from our observations do we calculate that the Big Bang occurred?
14 billion years ago
What is the term for the process in which lightweight atomic nuclei smash together and stick (or fuse) to make heavier nuclei?
nuclear fusion
How do stars live?
From nuclear fusion
How do stars die?
When it exhuasts its usable fuel
What happens when a massive star dies?
in titanic explosions called supernovae
What is a supernovae?
When a massive star dies through titanic explosions
Explain, "The farther away we look in distance, the further back we look in time"?
Because it takes time for light to travel through space
T or F
Any snapshot of a distant galaxy is a picture of both space and time?
True, because the light we see from the far side of a galaxy must have left on it journey before the light we see from the near side.
That is to say that the light we see is older from the far side than from what we see on the near side
What is meant by the observable universe?
Because the universe is @ 14 billion years old, we cannot observe light coming from anything more than 14 billion lights years away
Describe our solar system on the 1: 10 billionth scale?
1.Sun is the size of a large grapefruit;
2.Earth is the size of a ball point in a pen
Describe one way to put the scale of the Milky Way Galaxy into perspective
1:10 billionth scale becomes useless,
use 1: 10 to the 19 and the diameter of the Milky Way becomes @ the length of a football field
On a scale how many stars are there in the Universe
Using a grain of sand to equal a star, the number is comparable to the number of every grain of dry sand on every beach on Earth or 10 to the 22 power
Based on the cosmic calendar when did you and your friends show up?
0.05 seconds ago
What is the Earth's ecpliptical plane?
The Earth's orbital path
What is the axis tilt?
only in relation to the ecliptic plane, the Earth's axis tilt is 23.5 degrees from the EArth's ecliptical plane.
What is the shape of the Milky Way
A huge disc shaped collection of stars with a central bulge with a spehrical halo that surrounds the entire disk
Where is our solar system located in the Milky Way?
@ 28,000 light years from the center of the Milky Way, sort of on the fringe
What is meant by our "cosmic address"?
When describing our place in the universe
What is the term for the the Sun and all of the objects that orbit it?
Our solar system
T or F
Asteroids and comets are included as part of our solar system.
True
What is the term for the huge, disk-shaped collection of stars called which our solar system is located?
Milky Way
T or F
The Milky Way is a solar system.
False,
It is the Milky Way Galaxy
What is the term for a great island of stars in space, containing from a few hundred million to a trillion or more stars.
Galaxy
T or F
The Milky Way is relatively large.
True
Approx. how many stars are in the Milky Way Galaxy?
100 Billion
Where is our solar system located in the Milky Way Galaxy?
little over halfway from the galactic center to the edge of the galactic disk
T or F
The Milky Way is one of the 2 largest among @ 40 galaxies in the LOCAL GROUP.
True
WHat is the term for groups of galaxies with moe than a few dozen members?
Galaxy Clusters
On a large scale how do galxies and galaxy cluster appear?
In giant chains and sheets
What is the term for galaxies and galxy clusters that are more tightly packed in some places?
Superclusters
What is the term for the supercluster that our Local Group belongs to?
Local Supercluster
What is the term for the sum total of all matter and energy, encompassing the superclusters and voids and everything within them?
The Universe
T or F
The Universe is expanding?
True
What is the term for the event that was the start of the Universe?
The Big Bang
Approx. how old is the Universe?
14 Billion years old
T or F
Individual galaxies and their contents do not expand.
True
When is it estimated that most galaxies including the Milky Way were formed?
within a few years of the Big Bang
What is the term used to describe the evolution of a star?
Life cycle
What is the result when gravity compresses the material in a cloud to the point where the center becomes dense enough and hot enough to generate energy by nuclear fusion?
A star is born
T or F
In its final death throes a star blows much of its content back out into space.
True
What is the term for the titanic explosions that occur when stars die?
Supernovae.
What is the term for the large glowing ball of gas that generates heat and light through nuclear fusion in its core?
A staR
wHAT IS THE TERM FOR A MODERATELY LARGE OBJECT THAT ORBITS A STAR and shines primarily by reflecting light from its star?
A planet
What are the 3 criteria for an object to be considered a planet?
It:
1. orbits a star
2. is large enough for its own gravity to make it round
3. has cleared most other objects from its orbital path.
Why isn't Pluto considered a planet any longer?
It has not cleared its orbital path.
What is Pluto considered now?
A dwarf planet
What is the term for an object that orbits a planet?
Moon or satellite
What is the term for a relatively small and rocky object that orbits a star?
asteroid
What is the term for a relatively small and ice-rich object that orbits a star?
Comet
What is the term for the Sun and all the material that orbits it, including planets, dwarf planets, and small solar system bodies?
Solar System
What is the term for a star, sometimes more than one star, and any polanets and other materials that orbit?
Star System
How many star systems contain 2 or more stars?
1/2 or one half
What is the term for the portion of the ntire universe that can be seen from Earth, at least in princi[;e?
Observable Universe
What is the distance that light can travel in 1 year?
A light year
In kilometers, how long is a light year?
9.46 trillion kilometers
T or F
A light year is a measure of time?
False,
It is a measurement of distance, 9.46 trillion km (kilometers)
What is the term for the increase in the average distance between galaxies and their contents
Expansion of the Universe
What is the formula for distance?
distance= speed x time
What is the speed of lightin kilometers?
300,000km/second
What is the speed of light in miles?
186,000 miles/second
T or F
Galaxies funciton as cosmic recycling plants
True
What elements did the Universe contain in its earliest stage?
Hydrogen and helium
Name the 4 elements that make up primarily us and the Earth?
1. Carbon
2. Nitrogen
3. Oxygen
4. Iron
What is thought to be manufacturer of the additional elements?
The stars, either through nuclear fusion
How long ago is it thought that our solar system was formed?
4.5 Billion years ago
What is the distance of a light year in miles?
6 trillion miles.
T or F
THE FARTHER AWAY WE LOOK IN DISTANCE, THE FURTHER BACK WE LOOK IN TIME.
True
Name the brightest star in the night sky?
Sirius
How far away is Sirius?
8 light years away.
T or F
When we look at Sirius, we are seeing it in real time.
False,
we see it as it was @ 8 years ago.
How many light years away from us is the Andromeda Galaxy?
2.5 million light years
What is the other name for the Andromeda Galaxy?
M31
Approx. how large is the Andromeda Galaxy?
100,000 light years in diameter
What is the term for the smaller objects that orbit the Sun, including asteroids and comets?
Small solar system bodies
Name the only other world man has stepped onto?
Our Moon
What is the nearest star system to our own?
Alpha Centauri @ 4.4 light years away.
Name the space probe that the US launched in 1977, that flew past Jupiter, 1979, Saturn in 1981, Uranus in 1986 and Neptune in 1989 and is now bound for the stars?
Voyager 2
What is the rough est. of the toal number of stars in the o servable universe?
22
10

or 10 to the 22nd power
On a cosmic calendar on which the Big Bang takes place on the in the first instant of January 1, how long is approximately 1 month?
1.16 Billion years
How long did the death of the dinosaurs take place?
65 million years ago
What is the term for the flat plane that defines the Earth's orbital path?
Ecliptical plane
What is the degree of tilt for the Earth's axis?
23.5 degrees from a line perpendicular to the ecliptic plane
In what direction is the Earth's axis tilt pointed?
Towards Polaris aka the North Star
What is the other name for the star Polaris?
North Star
T or F
The Earth orbits the Sun in the same direction that it rotates on its axis.
True
In what direction does the Earth rotate and orbit the Sun?
Counter clockwise as viewed from above the North Pole
What is the term for the region of the Sun and its nearby stars?
Local solar neighborhood
How fast are we moving relative to nearby stars?
70,000km/hr or 40,000mi/hr
T or F
We are moving 3x as fast as the Space Station orbits the Earth in relation to neaby stars.
True
T or F
In 10,000 years, the constellations will be noticeabaly different from those we see today.
True
Approx. what is the distance from the galactic center of the Milky Way is our solar system?
28,000 light years
What are the 2 astonishing facts discovered by Hubble @ about outside our Local Group
1. Virtually every galaxy outside the Local Group is moving away from us.
2. The more distant the galaxy, the faster it appears to be racing away.
Name the example that is often cited to explain how the universe is expanding?
Raisins in a cake
How fast do we spin around Earth's axis?
1,000 km/hr
How fast does the Earth orbit the sun?
100,000 km/hr
T or F
We are latecom ers on the scale of cosmic time.
True